T E C HNICAL FIE LD

T he present disclosure relates to a forming method and apparatus. T he method and apparatus can be used in the forming of a wall section of a cast-in-place wall. More particularly, but not exclusively, the present disclosure relates to apparatus for forming a mould cavity to form a wall section; and a method of forming a wall section.

BAC KG R OU ND

T here is a continuing demand for basement living space in cities, such as London, where space is at a premium. The basement may be created or enlarged by performing excavation within an existing building. The walls of the building are supported during the excavation process to preserve building integrity, for example using telescopic tubular steel props (also known as jack posts or Acrow props). The basement is completed by building load-bearing walls which support the original walls of the building. The load-bearing walls may also function as retaining walls, for example to retain earth or soil. T he load-bearing walls may comprise one or more cast-in-place walls which is cast in situ and forms an integral part of the structure. (This is distinct from a precast component which is formed remotely, for example at an off-site location, and then transported to the desired location.) T he process comprises forming a temporary structure which forms a mould cavity into which concrete is poured. It is important that voids or pockets are not formed during the casting process as these may result in inherent weaknesses in the wall structure. Another potential problem arises if the loads applied by the concrete cause the mould cavity to deform. T hese problems are exacerbated for larger mould cavities as a result of the higher loads. At least in certain embodiments, the present invention seeks to overcome or ameliorate some of the aforementioned problems.

S U MMARY O F T H E INVE NTIO N

Aspects of the present invention relate to apparatus for forming a mould cavity to form a wall section; and a method of forming a wall section as claimed in the appended claims.

According to a further aspect of the present invention there is provided apparatus for forming a mould cavity to form a wall section of a cast-in-place wall, the apparatus comprising:

a plurality of forming plates for forming a support wall which defines at least one wall of the mould cavity; and

a support assembly for supporting the forming plates;

wherein the forming plates are configured to be assembled into a first row comprising at least one of said forming plates, the first row forming the mould cavity for a first concrete pouring operation; and into a second row comprising at least one of said forming plates, the second row forming the mould cavity for a second concrete pouring operation. The apparatus is configured to enable the first row to be formed in a first assembly stage; and the second row to be formed in a second assembly stage.

At least in certain embodiments, the first concrete pouring operation is performed after the first assembly stage; and the second concrete pouring operation performed afterthe second assembly stage. T hus, the first and second concrete pouring operations are staggered. The forming of the wall section is a multi-stage process. At least in certain embodiments, the apparatus enables multiple concrete pouring operations to be performed. The wall section may thereby be formed in a plurality of pouring operations. These concrete pouring operations may be more readily controlled and/or monitored. T he cast-in-place wall may comprise or consist of at least one said wall section. T he apparatus may provide a temporary support structure for forming the wa ll section. Once the wall section has been formed, the apparatus may be removed. At least in certain embodiments, the apparatus is reusable. The apparatus may be re-configurable to enable the forming of wall sections having different shapes and/or dimensions.

T he first concrete pouring operation comprises pouring concrete into the mould cavity formed by the first row. T he concrete may be poured up to the level of the top of the first row in the first concrete pouring operation. The second concrete pouring operation comprises pouring concrete behind the second row. T he concrete may be poured up to the level of the top of the second row in the second concrete pouring operation.

In arrangements in which said first row and/or said second row comprise a plurality of said forming plates, the forming plates in each row may be configured to connect with each other. Alternatively, or in addition, the forming plates in the first row may be configured to connect to the forming plates in the second row. The forming plates in the second row may connect to the forming plates in the first row along a common edge, for example along a horizontal edge. The forming plates may comprise cooperating features which interlock with each other to connect adjacentforming plates. T he cooperating features may be arranged to connect forming plates disposed in one or more of the following relative positions: above, below and beside. T he cast-in-place wall may be formed on a kick (which may function as a base or foundation for the cast-in-place wall). The apparatus may comprise means for forming the kick. T he kick forming means may comprise a kick forming box. An initial concrete pouring operation may be performed to pour concrete into the kick forming box to form the kick. T he kick may be formed before forming the cast-in-place wall or concurrently with forming the cast-in-place wall. The forming plates may be configured to cooperate with the kick forming means.

T he cast-in-place wall may comprise a bottom and a top. The apparatus may be configured to form the cast-in-place wall from the bottom to the top. The forming plates may be configured such that the second row may be assembled on top of the first row. In a variant, the apparatus may be configured to form the cast-in-place wall from the top to the bottom. The cast-in-place wall may be formed during excavation, for example as a shaft or trench is excavated. T he forming plates may be configured such that the second row may be assembled below the first row.

T he forming plates are suitable for forming at least one surface of the wall section. For example, the forming plates may form an outer surface of the wall section. T he forming plates may comprise a panel, for example having a major surface forforming the at least one surface of the wall section. Alternatively, or in addition, the forming plates may form a side wall and/or an upper surface of the wall section.

T he forming plates in the first row may be configured to connect to the forming plates in the second row. T he forming plates may be configured to connect to each other along a common edge, for example along a horizontal edge, to connect the forming plates in said first row to the forming plates in said second row. The forming plates may comprise cooperating features.

T he forming plates may be configured to connect to an adjacent forming plate. The forming plates may be configured to connect to each other along a common edge, for example along a vertical edge, to connect adjacent forming plates in said first row and/or said second row.

T he forming plates may be formed from a sheet metal. In a variant, the or each forming plate may comprise a pre-cast structure. F or example, the or each forming plate may comprise a pre-cast concrete panel. In this arrangement the pre-cast structure may be incorporated into the cast-in- place wall. T he pre-cast structure may comprise one or more interlocking features for cooperating with a corresponding feature in another pre-cast structure. T he pre-cast structure may comprise one or more locking features for cooperating with the concrete poured into the mould cavity.

T he apparatus may comprise means for supporting at least one reinforcing member in said mould cavity. The reinforcing member may, for example, comprise a reinforcing steel bar. T he apparatus may be configured to support the at least one reinforcing member during said first concrete pouring operation and/or during said second concrete pouring operation. In certain embodiments, the means for supporting the at least one reinforcing member may comprise a support member which may be at least partially embedded in the concrete. The support member may be sacrificial and may be embedded in the cast-in-place wall.

T he support means may be configured to support the at least one reinforcing member such that at least a portion thereof projects outside of the mould cavity for integration into an adjacent wall section. T he support means may, for example, be configured to support the at least one reinforcing member to project from a side of the mould cavity.

T he apparatus may comprise at least one side forming plate for forming a side wall of the wall section. T he at least one side forming plate may comprise a projection and/or a recess forforming a feature for interlocking with an adjacent wall section.

T he at least one side forming plate may be configured to support at least one reinforcing member. T he at least one side forming plate may be configured to support the at least one reinforcing member in a substantially horizontal position. The at least one side forming plate may comprise at least one aperture for receiving said at least one reinforcing member.

T he apparatus may comprise at least one upper forming plate for forming an upper surface of the wall section. The at least one upper forming plate may comprise a projection and/or a recess for forming a feature for interlocking with an adjacent wall section. The at least one upper forming plate may be configured to support at least one reinforcing member. T he at least one reinforcing member may be supported in a substantially vertical position. The at least one upper forming plate may comprise at least one aperture for receiving said at least one reinforcing member. At least one of said forming plates may comprise an elongate projection for forming a channel in the wall section. The resulting channel may, for example, be used to trace electrical cables and/or conduits in the wall section. T he elongate projection may have a positive draft angle to facilitate removal from the wall section when the concrete has cured. T he support assembly may comprise at least one upright. T he forming plates could be mounted directly to said at least one upright. Alternatively, or in addition, the support assembly may comprise at least one support arm. T he forming plates may be mountable to said at least one support arm. At least in certain embodiments, the at least one support arm may be movable to an undeployed position, for example to provide access. T he at least one support arm may be articulated or may be pivotally mounted to said at least one upright.

T he apparatus described herein may be used to form opposing outer surfaces of the wall section of the cast-in-place wall. The plurality of forming plates may comprise at least one first forming plate and at least one second forming plate. T he at least one first forming plate may define a first wall of the mould cavity; and the at least one second forming plate may define a second wall of the mould cavity. The first and second walls may be opposing walls. In use, the mould cavity may be formed between the first and second walls. The first and second forming plates may be configured to be assembled into first rows in said first and second walls respectively. The first rows in said first and second walls may each comprise at least one of said first and second forming plates. T he first rows may form the mould cavity for a first concrete pouring operation. T he first and second forming plates may be configured to be assembled into second rows in said first and second walls respectively. T he second rows in said first and second walls may each comprise at least one of said first and second forming plates. T he second rows may form the mould cavity for a second concrete pouring operation.

According to a further aspect of the present invention there is provided apparatus for forming a mould cavity to form a wall section of a cast-in-place wall, the apparatus comprising:

at least one forming plate for forming a support wall which defines at least one wall of the mould cavity; and

means for supporting at least one reinforcing member in said mould cavity. T he support means may be incorporated into one or more of said forming plates. T he support means may be configured to support the at least one reinforcing member such that at least a portion thereof projects outside of the mould cavity for integration into an adjacent wall section.

T he support means may be configured to support the at least one reinforcing member to project from a side of the mould cavity.

T he support means may be configured to support the at least one reinforcing member to project from a top or a bottom of the mould cavity. T he apparatus may comprise means for forming at least one feature for cooperating with an adjacent wall section. The at least one feature may be a male or female profile. The forming means may form a keyed interface in the wall section for cooperating with the adjacent wall section. At least in certain embodiments, the adjacent wall section may be cast around the at least one feature.

T he forming means is configured to cast the at least one feature in a side of the wall section. T he forming means may comprise a side forming plate. The side forming plate may comprise a projection and/or a recess for forming the at least one feature for interlocking with an adjacent wall section. T he apparatus may comprise an elongate projection for forming a channel in the wall section.

According to a further aspect of the present invention there is provided apparatus for forming a mould cavity to form a wall section of a cast-in-place wall, the apparatus comprising:

at least one forming plate for forming a support wall which defines at least one wall of the mould cavity; and

means for forming at least one feature for cooperating with an adjacent wall section. T he at least one feature may form a water joint between the adjacent wall sections. T he forming means may form a keyed interface in the wall section for cooperating with the adjacent wall section. At least in certain embodiments, the adjacent wall section may be cast around the at least one feature.

T he forming means may be configured to castthe at least one feature in a side of the wall section.

T he forming means may comprise a side forming plate. The side forming plate may comprise a projection and/or a recess for forming the at least one feature.

T he apparatus may comprise an elongate projection for forming a channel in the wall section.

According to a further aspect of the present invention there is provided apparatus for forming a mould cavity to form a wall section of a cast-in-place wall, the apparatus comprising:

at least one forming plate for forming a support wall which defines at least one wall of the mould cavity;

the at least one forming plate comprising a side forming plate for forming a side of the support wall, wherein the side forming plate comprises a projection and/or a recess for forming a feature for interlocking with an adjacent wall section.

According to a further aspect of the present invention there is provided a method of forming a cast-in-place wall comprising at least a first wall section and a second wall section, the method comprising:

casting the first wall section, the first wall section having at least one first feature for cooperating with the second wall section; and casting the second wall section adjacent to the first wall section such that the second wall section cooperates with the at least one first feature of the first wall section. The second wall section may be cast after the first wall section. T he first wall section may be cast in a first mould cavity. T he second wall section may be cast in a second mould cavity.

T he second mould cavity may be at least partially defined by the first wall section. T he method comprise forming the second wall section using a side of the first wall section as part of the mould, such that the at least one feature cooperates with the second wall section.

T he second wall section may comprise at least one second feature for cooperating with the at least one first feature. The at least one first feature and the at least one second feature may cooperate to form a joint T he at least one first feature may comprise a first projection and/or a first recess.

T he at least one first feature may be configured to interlock with the second wall section. T he at least one first feature may be formed integrally with the first wall section.

According to a further aspect of the present invention there is provided a method of forming a cast-in-place wall comprising at least a wall section, the method comprising:

assembling a mould cavity using at least one forming plate to form a support wall;

supporting at least one reinforcing member in said mould cavity; and

casting the first wall section in the mould cavity with the at least one reinforcing member supported therein.

T he at least one reinforcing member may be supported in the mould cavity such that a portion thereof projects out of the wall section for integration into an adjacent wall section.

T he at least one reinforcing member may be supported in the mould cavity so as to project from a side of the wall section.

T he at least one reinforcing member may be supported in the mould cavity so as to project from a top or a bottom of the wall section.

T he at least one reinforcing member may be supported by a support member mounted to the at least one forming plate; and/or an aperture formed in the at least one forming plate. According to a further aspect of the present invention there is provided a method of forming a wall section of a cast-in-place wall using a forming apparatus which defines a mould cavity, the forming apparatus comprising a plurality of forming plates; the method comprising:

assembling a first row comprising at least one of said forming plates and performing a first concrete pouring operation; and

assembling a second row comprising at least one of said forming plates and performing a second concrete pouring operation. T he first row may be formed in a first assembly stage; and the second row may be formed in a second assembly stage. At least in certain embodiments, the first concrete pouring operation is performed after the first assembly stage; and the second concrete pouring operation performed after the second assembly stage. T hus, the first and second concrete pouring operations are staggered. It will be understood that the forming of the wall section is a multi-stage process. At least in certain embodiments, the method comprises multiple concrete pouring operations which are performed as separate operations. T he pouring of the concrete into the mould cavity may be more readily controlled and/or monitored during said separate pouring operations. T he cast-in-place wall may comprise or consist of at least one said wall section.

T he forming plates are suitable for forming at least one surface of the wall section. T he forming plates may, for example, form an outer surface of the wall section.

At least in certain embodiments, the second concrete pouring operation may be performed before the concrete poured during the first concrete pouring operation has cured. T he first concrete pouring operation may comprise pouring concrete into the mould cavity formed by the first row. T he concrete may be poured up to the level of the top of the first row in the first concrete pouring operation. T he second concrete pouring operation may comprise pouring concrete into the mould cavity formed by the second row. T he concrete may be poured up to the level of the top of the second row in the second concrete pouring operation. T he method may comprise connecting the forming plates in said first row with each other; and/or connecting the forming plates in said second row with each other. Alternatively, or in addition, the method may comprise connecting the forming plates in the first row to the forming plates in the second row. The method may comprise connecting the forming plates in the second row to the forming plates in the first row along a common edge, for example along a horizontal edge. T he method may comprise connecting adjacent forming plates disposed one above the another; or beside each other. T he method may comprise connecting the forming plates in the first and second rows to each other. The forming plates in the second row are connected to the forming plates in the first row along a common edge, for example along a horizontal edge. T he forming plates may comprise cooperating features which interlock with each other to connect adjacent forming plates.

T he method may comprise forming a kick for supporting the cast-in-place wall. The method may comprise forming the kick using kick forming means, such as a kick forming box. An initial concrete pouring operation may be performed to pour concrete into the kick forming box to form the kick. The kick may be formed before forming the cast-in-place wall or concurrently with forming the cast-in-place wall. The forming plates may be configured to cooperate with the kick forming means.

T he cast-in-place wall may comprise a top and a bottom. The method may comprise forming the cast-in-place wall from the bottom to the top. T he method may comprise assembling the second row on top of the first row. In a variant, the method may comprise forming the cast-in-place wall from the top to the bottom. The cast-in-place wall may be formed during excavation, for example as a shaft or trench is excavated. The method may comprise assembling the second row below the first row.

T he first row may comprise a plurality of said forming plates. T he method may comprise connecting adjacent forming plates in the first row to each other. T he second row may comprise a plurality of said forming plates, the method comprising connecting adjacent forming plates in the second row to each other. The forming plates in said first and second rows may be connected along a common edge, for example along a horizontal edge.

T he method may comprise supporting at least one reinforcing member during said first concrete pouring operation and/or said second concrete pouring operation. The reinforcing member may be a reinforcing steel bar. T he forming apparatus may be configured to support the at least one reinforcing member. T he method may comprise locating the at least one reinforcing member in a support means, such as an aperture, provided in said forming apparatus. The at least one reinforcing member may be supported such that at least a portion thereof projects outside of the mould cavity for integration into an adjacent section of the wall section. T he at least one reinforcing member may project outwardly from a side of the wall section. T he forming apparatus may comprise at least one side forming plate for forming a side of the wall section. T he at least one side forming plate may be profiled to form a feature in the wall section for interlocking with an adjacent wall section. T he feature may form a key for cooperating with an adjacent wall section. At least one reinforcing member may be supported by the at least one side forming plate. T he forming apparatus may be supported by one or more reinforcing members during said first concrete pouring operation and/or said second concrete pouring operation.

T he method may comprise supporting said at least one reinforcing member during said first concrete pouring operation and/or said second concrete pouring operation.

T he method may comprise forming a channel in the wall section during the forming process. At least one of said forming plates may comprise an elongate projection for forming said channel.

T he cast-in-place wall may comprise or consist of one or more of said wall sections. In arrangements in which the cast-in-place wall comprises a plurality of said wall sections, the method may be repeated to form a plurality of said wall sections. The method may comprise forming a first wall section and repeating the process to form a second wall section. The first and second wall sections may be disposed adjacent to each other. A side wall of the first wall section may define a portion of the mould cavity for forming the second wall section.

T he method may comprise supporting said forming plates to perform said first concrete pouring operation and said second pouring operation. A support assembly may be used to support said forming plates. The support assembly may comprise at least one support arm and at least one upright

T he method described herein may be used to form opposing outer surfaces of the wall section of the cast-in-place wall. The plurality of forming plates may comprise at least one first forming plate and at least one second forming plate. The method may comprise using at least one first forming plate to define a first wall of the mould cavity; and using at least one second forming plate to define a second wall of the mould cavity. The first and second walls may be opposing walls. In use, the mould cavity may be formed between the first and second walls. The first and second forming plates may be configured to be assembled into first rows in said first and second walls respectively. T he first rows in said first and second walls may each comprise at least one of said first and second forming plates. T he first rows in said first and second walls may form the mould cavity for a first concrete pouring operation. The first and second forming plates may be configured to be assembled into second rows in said first and second wa lls respectively. T he second rows in said first and second walls may each comprise at least one of said first and second forming plates. T he second rows may form the mould cavity for a second concrete pouring operation. T he method may comprise repeating the process to form one or more additional rows. According to a further aspect of the present invention there is provided a method of forming a wall section of a cast-in-place wall using a forming apparatus which defines a mould cavity, the forming apparatus comprising a plurality of forming plates; the method comprising:

performing a first ground excavation operation to form a hole;

assembling a first row comprising at least one of said forming plates in said hole to form a first mould cavity;

performing a first concrete pouring operation at least partially to fill said first mould cavity; performing a second ground excavation operation to extend the hole;

assembling a second row comprising at least one of said forming plates in said hole after said second ground excavation operation to form a second mould cavity; and

performing a second concrete pouring operation at least partially to fill said second mould cavity.

T he first ground excavation may form a hole, such as a shaft or trench. T he second ground excavation may be performed to enlarge the hole, for example to increase the depth of the hole. T he method may comprise additional ground excavation operations; forming plate assembly operations; and concrete pouring operations.

According to a further aspect of the present invention there is provided apparatus for forming an integrated water impermeable layer in a cast-in-place wall, the apparatus comprising:

at least one impermeable member for forming the water impermeable layer; and anchoring means for anchoring the at least one impermeable member to the cast-in- place wall, the anchoring means being configured to be at least partially embedded in concrete during formation of the cast-in-place wall. At least in certain embodiments, the water impermeable layer forms an integrated waterproof layer. T he water impermeable layer may be used to provide waterproof tanking of the cast-in-place wall.

T he anchoring means may comprise at least one anchor member for projecting into a mould cavity into which the concrete is introduced to form the cast-in-place wall. The anchor member may comprise or consist of an anchor which, in use, is at least partially embedded in the concrete forming the cast-in-place wall. The anchor may comprise a head portion for resisting withdrawal of the anchor member from the cast-in-place wall. The anchor may comprise a negative return angle for resisting withdrawal of the anchor member from the cast-in-place wall. T he anchor member may form a fastening plug for receiving a mechanical fastener, such as a screw. T he anchor member may comprise a fastener receiving aperture for receiving a mechanical fastener. In use, the anchor member is pre-installed in the cast-in-place wall and, at least in certain embodiments, may extend through the water impermeable layer. Thus, the anchor member may provide a fixing point without the need to form a separate hole in the water impermeable layer.

T he anchor member may comprise a connector for releasably connecting the anchoring means to a forming plate for forming the mould cavity. The connector may, for example, comprise a projection for location in an aperture provided in the forming plate. T he connector may comprise one or more resilient members for engaging the forming plate. T he resilient members may be spring biased against the forming plate to connect the anchoring means to the forming plate. T he connector may comprise a threaded section. The threaded section of the connector may be screwed into a forming plate prior to forming the mould cavity. T he forming plate may, for example, be composed of plywood or other material suitable for receiving a threaded fastener. T he forming plate may remain in-situ after the concrete has cured to form an inner surface. Alternatively, the threaded section may extend through the forming plate to receive a cooperating fastener, such as a nut, to mount the impermeable member to the forming plate. T he fastener may be released to remove the forming plate after the concrete has cured. T he anchor may form a head of a screw or bolt which remains spaced apart from a surface of the impermeable member so that the head may be encapsulated in the concrete. T he connector may be removable. T he anchor member may comprise a frangible section to facilitate removal of the connector. Alternatively, the connector may be mounted in the fastener receiving aperture. T he fastener receiving aperture may be exposed when the connector is removed. T he anchor may be provided at a first end of the anchor member and the connector may be provided at a second end of the anchor member. T he first and second ends of the anchor member may be opposite to each other.

E ach impermeable member may comprise at least one aperture for receiving a respective anchor member. T he anchor member may have an enlarged base for engaging a surface of the impermeable member.

T he anchoring means may comprise at least one aperture formed in the impermeable member for receiving the concrete during formation of the cast-in-place wall.

T he apparatus may comprise sealing means for forming a seal between two of said impermeable members disposed adjacent to each other. In use, each impermeable member may abut against an adjacent impermeable member. Alternatively, or in addition, in use, each impermeable member may partially overlap an adjacent impermeable member. E ach impermeable member may comprise one or more overlap member for at least partially overlapping an adjacent one of said impermeable members.

E ach impermeable member may comprise a releasable fastener for mounting the impermeable member to a forming plate.

T he impermeable member may comprise or consist of a flexible membrane. Alternatively, the impermeable member may comprise a pre-formed panel. The pre-formed panel may comprise a rigid or semi-rigid structure. T he anchoring means may be integrated with the impermeable member. Alternatively, the anchoring means may be installed in a subsequent procedure step.

According to a further aspect of the present invention there is provided an anchor member for anchoring an impermeable member to a cast-in-place wall, the anchor member comprising an anchor configured to be at least partially embedded in concrete during formation of the cast-in- place wall.

T he anchor member may comprise a fastener receiving aperture for receiving a mechanical fastener. The anchor member may be pre-installed in the cast-in-place wall and, at least in certain embodiments, may extend through the water impermeable layer. T he anchor member may provide a fixing point without the need to form a separate hole in the water impermeable layer. T he anchor member may project into a mould cavity into which the concrete is introduced to form the cast-in-place wall.

T he anchor may comprise a head portion for resisting withdrawal of the anchor member from the cast-in-place wall. The anchor member may comprise a negative return angle for resisting withdrawal of the anchor member from the cast-in-place wall. T he fastener receiving aperture may be formed in a base of the anchor member. In use, the base may locate externally of the impermeable member and the cast-in-place wall. T hus, the fastener receiving aperture is accessible after forming the cast-in-place wall.

T he anchor member may comprise a connector for releasably connecting the anchoring means to a forming plate for forming the mould cavity. The connector may, for example, comprise a projection for location in an aperture provided in the forming plate. T he connector may comprise one or more resilient members for engaging the forming plate. T he resilient members may be spring biased against the forming plate to connect the anchoring means to the forming plate. T he connector may be removable. T he anchor member may comprise a frangible section to facilitate removal of the connector. Alternatively, the connector may be mounted in the fastener receiving aperture. T he fastener receiving aperture may be exposed when the connector is removed.

T he connector may comprise a threaded section. The threaded section of the connector may be screwed into a forming plate prior to forming the mould cavity. T he forming plate may, for example, be composed of plywood or other material suitable for receiving a threaded fastener. T he forming plate may remain in-situ after the concrete has cured to form an inner surface. Alternatively, the threaded section may extend through the forming plate to receive a cooperating fastener, such as a nut, to mount the impermeable member to the forming plate. T he fastener may be released to remove the forming plate after the concrete has cured. T he anchor may form a head of a screw or bolt which remains spaced apart from a surface of the impermeable member so that the head may be encapsulated in the concrete.

T he anchor may be provided at a first end of the anchor member and the connector may be provided at a second end of the anchor member. T he first and second ends of the anchor member may be opposite to each other.

T he anchor member has been described herein as anchoring an impermeable member to a cast- in-place wall. T he impermeable member may be used to form a waterproof layer, for example to provide tanking of a wall. T he impermeable member may be used to form a damp proofing layer. Other uses and applications for the anchor member are also envisaged. For example, the anchor member may be anchored in mortar provided between bricks when building a wall.

T he apparatus may comprise at least one second panel member configured to form a second impermeable layer. T he second impermeable layer may be formed inwardly of the first impermeable layer. The first and second impermeable layers may be spaced apart from each other such that a cavity is formed between them. The second impermeable layer may be mounted to the first impermeable layer.

According to a further aspect of the present invention there is provided an apparatus for forming a water impermeable layer, the apparatus comprising:

at least one first panel member for forming a first impermeable layer; and

at least one second panel member for forming a second impermeable layer;

wherein the apparatus is configured to form a cavity between the first and second impermeable layers. At least in certain embodiments, the cavity may be at least substantially sealed. At least in certain embodiments, the cavity may support an operating pressure which is greater than or less than atmospheric pressure. The apparatus may include at least one port for introducing a gas into the cavity to increase an operating pressure of the cavity to greater than atmospheric pressure; and/or removing a gas from the cavity to decrease an operating pressure of the cavity to less than atmospheric pressure.

T he apparatus may comprise a control system for testing the integrity of the seals. The control system may monitor the operating pressure in the cavity to test the integrity of the seal. A pump may be provided to pump a gas into the cavity and/or to remove gas from the cavity. T he control system may measure an absolute value of the operating pressure in the cavity. Alternatively, or in addition, or may determine a rate of change of the operating pressure in the cavity. T he control system may be configured to increase the operating pressure in the cavity to a pressure greater than atmospheric and then to measure a change or a rate of change in the operating pressure with respect to time. Alternatively, the control system may be configured to reduce the operating pressure in the cavity to a pressure less than atmospheric pressure and then to measure a change or a rate of change in the operating pressure with respect to time. The control system may trigger an alarm if a determination is made that an integrity of a cavity has been compromised.

According to a further aspect of the present invention there is provided a method of forming an integrated water impermeable layer in a cast-in-place wall, the method comprising:

using at least one forming plate to form a support wall of a mould cavity;

providing at least one impermeable member on the at least one forming plate; and performing a concrete pouring operation at least partially to fill the mould cavity;

wherein the at least one impermeable member comprises anchoring means, the anchoring means being at least partially embedded in the concrete during the concrete pouring operation. At least in certain embodiments, the water impermeable layer forms an integrated waterproof layer. T he water impermeable layer may be used to provide waterproof tanking of the cast-in-place wall. E ach impermeable member may be releasably mounted to the at least one forming plate. T he impermeable member may be mounted to the at least one forming plate prior to forming the support wall. Alternatively, the impermeable member may be mounted to the at least one forming plate after forming the support wall and before performing the concrete pouring operation. T he method may comprise providing a plurality of said impermeable members. E ach impermeable member may be arranged to abut an adjacent impermeable member or to partially overlap an adjacent impermeable member. T he anchoring means may comprise at least one anchor member for projecting into the mould cavity.

T he method may comprise inserting the anchor member into a respective aperture formed in the impermeable member.

T he method may comprise comprising applying sealing means to form a seal between adjacent impermeable members. The sealing means may comprise a waterproof material, for example applied as an elongate strip over the joint formed between the impermeable members. The waterproof material may be fastened using adhesive or a plastic welding operation.

T he method may comprise installing at least one second panel member to form a second impermeable layer. T he second impermeable layer may be disposed inwardly of the first impermeable layer. T he first and second impermeable layers may be spaced apart from each other such that a cavity is formed between them. The second impermeable layer may be mounted to the first impermeable layer.

According to a further aspect of the present invention there is provided a method of forming a water impermeable layer, the method comprising:

using at least one forming plate to form a support wall of a mould cavity;

providing at least one first impermeable member on the at least one forming plate; performing a concrete pouring operation at least partially to fill the mould cavity; and installing at least one second panel member to form a second impermeable layer, the second impermeable layer being disposed inwardly of the first impermeable layer.

T he at least one first impermeable member may comprise anchoring means, the anchoring means being configured to be at least partially embedded in the concrete during the concrete pouring operation. T he first and second impermeable layers may be spaced apartfrom each other such that a cavity is formed between them. T he second impermeable layer may be mounted to the first impermeable layer. At least in certain embodiments, the method may comprise at least substantially sealing the cavity. In use, the cavity may support an operating pressure which is greater than or less than atmospheric pressure. At least one port may be provided for introducing a gas into the cavity to increase an operating pressure of the cavity to greater than atmospheric pressure; and/or removing a gas from the cavity to decrease an operating pressure of the cavity to less than atmospheric pressure. A drainage port may be provided, for example to drain water from the cavity. T he method may comprise testing an integrity of the cavity. T he method may comprise monitoring the operating pressure in the cavity to test the integrity of the seal. T he method may comprise pumping a gas into the cavity and/or removing a gas from the cavity. T he method may comprise measuring an absolute value of the operating pressure in the cavity. Alternatively, or in addition, the method may comprise measuring a rate of change of the operating pressure in the cavity.

According to a further aspect of the present invention there is provided apparatus for forming a cast-in-place wall, the apparatus comprising:

at least one forming plate for forming a first mould cavity to form a first wall section of the cast-in-place wall;

at least one forming plate forforming a second mould cavity to form a second wall section of the cast-in-place wall; and

a partitioning plate for separating the first mould cavity and the second mould cavity.

T he partitioning plate may be removable to enable mixing of a curable material in the first and second mould cavities.

T he partitioning plate may comprise a concave or convex section for forming an interlocking between said first and second wall sections.

T he first and second wall sections may be formed adjacent to each other.

According to a further aspect of the present invention there is provided a method of forming a mould cavity to form a cast-in-place wall, the apparatus comprising:

forming a first mould cavity to form a first wall section of the cast-in-place wall, the first mould cavity comprising a partitioning plate;

performing a first concrete pouring operation at least partially to fill said first mould cavity; forming a second mould cavity adjacent to the first mould cavity, the partitioning plate separating the first and second mould cavities;

performing a second concrete pouring operation at least partially to fill said second mould cavity; and

removing the partitioning plate from between the first and second mould cavities. T he first mould cavity may be formed and the first concrete pouring operation is completed prior to forming the second mould cavity. T he partitioning plate is removed from between the first and second mould cavities after the second concrete pouring operation to enable mixing of the concrete at the interface between the first and second mould cavities. T he term concrete used herein refers to cementitious materials either with or without a ballast, such as gravel or other aggregate material.

Within the scope of this application it is expressly intended thatthe various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. T hat is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. T he applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BR IE F DE S C RIPTIO N O F T HE DRAWING S

One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

F igure 1 shows a first perspective view of an apparatus according to an embodiment of the present invention installed in a trench;

F igure 2 shows a second perspective view of the apparatus shown in F igure 1 ;

F igure 3 shows first and second forming assemblies for use in the apparatus shown in F igures 1 and 2;

F igure 4 shows a third forming assembly for use in the apparatus shown in F igures 1 and 2;

F igure 5 shows a first variant of the third forming assembly shown in F igure 5;

F igure 6 shows a second variant of the third forming assembly shown in F igure 5;

F igures 7A to 7F illustrate the sequential stages in forming a vertical wall section using the apparatus according to an embodiment of the present invention;

F igure 8A to 8M illustrate the sequential stages in forming a vertical wall section using the apparatus according to a further embodiment of the present invention;

F igures 9A and 9B illustrate a water impermeable layer formed integrally with the cast- in-place wall W described herein;

F igures 10A and 10B illustrate a variant ofthe water impermeable layer shown in F igures

9A and 9B; and

F igure 1 1 illustrates a variant of the apparatus shown in F igures 9A and 9B to form a sealed chamber between first and second water impermeable layers. DE TAILE D DE S C RIPTION

An apparatus 1 for forming a cast-in-place wall W in accordance with an embodiment of the present invention will now be described with reference to the accompanying figures. The apparatus 1 described herein is a modular system that is re-configurable to form cast-in-place walls W having different configurations. T he apparatus 1 is described herein with reference to a domestic building project by way of example. However, the apparatus 1 is not limited in this respect and could be employed in other applications, including commercial building projects. T he apparatus 1 is re-usable.

T he cast-in-place wall W is cast in-situ (i.e. on-site) and forms a load-bearing structural component. T he cast-in-place wall W is formed from a cementitious material, which in the present embodiment is concrete C . T he cast-in-place wall W comprises one or more of said wall sections 2. The wall section 2 extends vertically, typically to the full height of the cast-in-place wall W. A plurality of the wall sections 2 can be arranged next to each other to form the cast-in-place wall W. As described herein, adjacent wall sections 2 may interlock with each other or may be connected to each other by one or more reinforcing members.

T he apparatus 1 is assembled to form a support wa ll 3 which operatively defines at least a portion of a mould cavity 4 into which the concrete C is poured. It will be understood that the mould cavity 4 is formed on-site at the location where the cast-in-place wall W is to be installed. The apparatus 1 comprises a plurality of forming assemblies 5-n and a support assembly (denoted generally by the reference numeral 7). T he forming assemblies 5-n combine to form a support wall 6 which defines at least one wall of the mould cavity 4. T he forming assemblies 5-n and the support assembly 7 in the present embodiment are fabricated from steel. The forming assemblies 5-n are operatively arranged in a series of rows R n, each comprising one or more of said forming assemblies 5-n. T he rows R n are assembled one on top of the next and the forming assemblies 5-n in consecutive rows connect together. As described herein, the or each wall section 2 is formed in multiple stages. A row R n is assembled to form the mould cavity 4 and the concrete C is introduced into the mould cavity 4 formed by that row R n. T he next row R n is assembled on top of the existing row R n to extend the mould cavity 4 vertically upwardly and the concrete C is introduced into the extended portion of the mould cavity 4. The process is repeated to form the wall section 2 to the desired height T he forming assemblies 5-n are configured to be removable from the wall section 2 once the concrete C has cured. For example, those features of the forming assemblies 5-n that contact the concrete C are formed without negative draft angles.

T he support assembly 7 is configured to support the forming assemblies 5-n. A suitable method for mounting a support member in an upright position is known from the Applicant s earlier U K patent application G B 1405173.4, the contents of which is incorporated herein in its entirety by reference. The support assembly 7 comprises a plurality of uprights 10 and a plurality of support arm assemblies 1 1 -n. In use, the uprights 10 extend substantially vertically and are fixedly mounted in position. The uprights 10 may, for example, be mounted to a foundation. Alternatively, the uprights 10 may comprise a pile or other member driven into the ground. The uprights 10 comprise a plurality of apertures for mounting the support arm assemblies 1 1 -n. The apertures in the uprights 10 are equally spaced apart and are provided along the length of the uprights 10 to allow adjustment of the vertical position of the support arm assemblies 1 1 -n. The support arm assemblies 1 1 -n are mounted to the uprights 10.

T he support arm assemblies 1 1 -n each comprise a mounting bracket 12-n, a support arm 13-n and a mounting head 14-n. The mounting brackets 12-n comprise first and second T-shaped brackets 15-n suitable for positioning on opposing sides of the uprights 10. The T-shaped brackets 15-n each have two (2) apertures which align with the apertures provided in the uprights 10. T he mounting brackets 12-n are fastened to the uprights 10 using suitable mechanical fasteners (not shown), for example by aligning the apertures in the T-shaped brackets 15-n and the apertures in the uprights 10 and inserting a clevis pin or bolt. The support arms 13-n are pivotally mounted to the mounting brackets 12-n and pivot between an upright position and a substantially horizontal position. T he support arms 13-n are inoperable in the upright position and operable in the substantially horizontal position. T he support arms 13-n can be pivoted to the upright position to provide improved user access, for example in the passage between the forming assemblies 5-n and the uprights 10. The mounting heads 14-n are configured to engage the forming assemblies 5-n and to mount them in position. As shown in F igure 3, the mounting heads 14-n comprise a U- shaped member 16 for engaging the forming assemblies 5-n. The forming assemblies 5-n are connected to the mounting heads 14-n using suitable mechanical fasteners, such as a clevis pin and clip arrangement. The length of the support arms 13-n is adjustable to allow the distance between the uprights 10 and the intended location of the support wall 6 to be adjusted. In the present embodiment, the mounting heads 14-n comprise a threaded member 17 having a male thread which is received in a cooperating threaded member (not shown) having a female thread which is mounted to the support arms 13-n. In an alternative embodiment the support arms 13-n may comprise first and second members translatable relative to each other, for example in a telescoping arrangement. T he relative position of the first and second members may be adjusted to change the length of the support arms 13-n. A locking mechanism may be provided to lock the position of the first and second members 14, 15 relative to each other.

T he support wall 6 is composed of a plurality of the forming assemblies 5-n arranged in two or more rows R n. E ach of the rows R n comprises at least one of the forming assemblies 5-n. As described herein, the forming assemblies 5-n are configured to interconnect with the forming assemblies 5-n in the row R n above and/or below. The configuration of the forming assemblies 5-n will now be described in more detail. In the present embodiment, there are three (3) iterations of the forming assemblies 5-n. The first, second and third forming assemblies 5-1 , 5-2, 5-3 are shown in F igures 3 and 4. T he first fornning assembly 5-1 and/or the second forming assembly 5- 2 and/or the third forming assembly 5-3 can be connected to each other to form one of said rows R n. T he support wall 6 is formed by assembling a plurality of said rows R n on top of each other.

As shown in F igure 3, the first forming assembly 5-1 comprises a first forming plate 20-1 , upper and lower first transverse mounting channels 21 -1 , 22-1 and a first connecting lug 23-1. In use, the first forming plate 20-1 faces into the mould cavity 4 and forms an outer (front) face of the wall section 2. The first forming plate 20-1 has a width of 900mm and a depth of 600mm. The first forming plate 20-1 comprises a first elongated projection 24-1 for forming a vertical channel in the outer surface of the wall section 2. T he resulting channel can, for example, be used to locate electrical cables in the wall section 2. To facilitate separation of the first forming assembly 5-1 from the wall section 2, the first elongated projection 24-1 comprises a positive draft angle. In the present embodiment, the first elongated projection 24-1 has a V-shaped profile, but other profiles are contemplated. A first side of the first forming plate 20-1 (the left hand side in the arrangement illustrated in F igure 3) comprises a first overlapping region 25-1 for forming a temporary lap joint with an adjacent one of said forming assemblies 5-n. T he upper and lower first transverse mounting channels 21 -1 , 22-1 are configured to be connected to at least one mounting head 14- n disposed on the support arm 13-n. T he upper and lower first transverse mounting channels 21 - 1 , 22-1 are fastened to the first forming plate 20-1 and extend alongside the first overlapping region 25-1. T he upper and lower first transverse mounting channels 21 -1 , 22-1 each comprise a C-shaped channel extending substantially parallel to a central longitudinal axis of the firstforming plate 20-1. In use, the upper and lower first transverse mounting channels 21 -1 , 22-1 preferably extend substantially horizontally. T he first connecting lug 23-1 projects vertically upwardly from the top of the first forming assembly 5-1 for cooperating with a like firstforming assembly 5-1 . T he first connecting lug 23-1 may be movably mounted so that it can be selectively deployed. T he first connecting lug 23-1 may, for example, pivot or translate between a deployed position and an un- deployed position.

As shown in Figure 3, the second forming assembly 5-2 comprises a second forming plate 20-2, upper and lower second transverse mounting channels 21 -2, 22-2, upper and lower receiving channels 26, 27 and a second connecting lug 23-2. In use, the second forming plate 20-2 faces into the mould cavity 4 and forms an outer (front) face of the wall section 2. The second forming plate 20-2 has a width of 900mm and a depth of 600mm. The second forming plate 20-2 comprises a second elongated projection 24-2 for forming a vertical channel in the outer surface of the wall section 2. The resulting channel can, for example, be used to locate cables in the wall section 2. To facilitate separation of the second forming assembly 5-2 from the wall section 2, the second elongated projection 24-2 comprises a positive draft angle. In the present embodiment, the second elongated projection 24-2 has a V-shaped profile, but other profiles are contemplated. A second side of the second forming plate 20-2 (the right hand side in the arrangement illustrated in F igure 3) is configured to overlap the first overlapping region 25-1 of the first forming assembly 5-1 to form the temporary lap joint. The upper and lower receiving channels 26, 27 are fastened to the second forming plate 20-2 and arranged to receive the projecting portions of the upper and lower first transverse mounting channels 21 -1 , 22-1 respectively. The upper and lower receiving channels 26, 27 may, for example, each comprise a hat channel fastened to the second forming plate 20-2. In use, the upper and lower second transverse mounting channels 21 -2, 22-2 of the first forming assembly 5-1 locate in said upper and lower receiving channels 26, 27 to connect the first and second forming assemblies 5-1 , 5-2 disposed adjacent to each other. A first side of the second forming plate 20-2 (the left hand side in the arrangement illustrated in F igure 3) comprises a second overlapping region 25-2 for forming a lap joint with an adjacent one of said forming assemblies 5-n. T he upper and lower second transverse mounting channels 21 -2, 22-2 are configured to be connected to at least one mounting head 14-n disposed on the support arm 13-n. The upper and lower second transverse mounting channels 21 -2, 22-2 are fastened to the second forming plate 20-2 and extend alongside the second overlapping region 25-2. The upper and lower second transverse mounting channels 21 -2, 22-2 each comprise a C-shaped channel extending substantially parallel to a central longitudinal axis of the second forming plate 20-2. T he second connecting lug 23-2 may be movably mounted so that it can be selectively deployed.

As shown in Figure 4, the third forming assembly 5-3 is a corner section and is arranged to form a vertical side wall of the wall section 2. When multiple wall sections 2 make up the cast-in-place wall W, the adjacent wall section 2 defines one side of the mould cavity 4 and at least one third forming assembly 5-3 forms the other side. The third forming assembly 5-3 comprises a third forming plate 20-3, upper and lower connecting lugs 28, 29, and first and second locating members 30, 31. T he third forming plate 20-3 comprises first and second end plates 32, 33 and an outer mounting plate 34. The first end plate 32 has a width of 900mm and a depth of 600mm; and the second end plate 33 has a width of 900mm and a depth of 600mm.T he first and second end plates are configured to form a vertical side wall of the wall section 2. The first and second end plates 32, 33 translate relative to each other to allow the width of the third forming plate 20-3 to be adjusted. This adjustment allows the apparatus 1 to be used to adjust the depth of mould cavity 4, thereby adjusting the thickness of the cast-in-place wall W. An inclined panel 35 is disposed between the outer mounting plate 34 and the first end plate 32. The inclined panel 35 is configured at least substantially to match the profile of the first and second elongated projections 24-1 , 24-2. The upper and lower connecting lugs 28, 29 are provided on the outer mounting plate 34 for connection to at least one mounting head 14-n disposed on the support arm 13-n. The first and second locating members 30, 31 are disposed on an inner surface of the outer mounting plate 34 and, in use, project into a bank of earth or a trench wall to help locate the third forming assembly 5-3. A method of forming a cast-in-place wall W in accordance with an aspect of the present invention will now be described with reference to F igures 1 and 2. In the arrangement illustrated in F igures 1 and 2, the cast in-place wall W is a wall of a basement, for example the basement of a domestic dwelling. In the illustrated example, the cast-in-place wall W is a retaining wall of an excavation comprising a trench T. The cast-in-place wall W is formed as a sidewall of the trench T. The cast- in-place wall W comprises a plurality of wall sections 2. T he wall sections 2 each form a vertical section of the cast-in-place wall W and are formed adjacent to each other. T he wall sections 2 are formed sequentially (i.e. one after the other) and each wall section 2 is formed only after the adjacent wall section 2 has been formed and the concrete C cured sufficiently to enable removal of at least the third forming assemblies 5-3 (which define the side walls of the mould cavity 4). T he process of forming the wall sections 2 will now be described. The support assembly 7 is installed in the trench T by mounting the uprights 10 in a substantially vertical position. T he uprights 10 in the present embodiment are self-supporting. The uprights 10 may, for example, be mounted to a foundation F formed at the bottom of the trench T. The uprights 10 are installed offset from the desired location of the cast-in-place wall W, for example on the opposite side of the trench T. In a variant of the apparatus 1 described herein, the forming assemblies 5-n could be mounted directly to the uprights 10.

T he forming assemblies 5-n are arranged to form the support wall 6 which defines at least one wall of the mould cavity 4. In the illustrated arrangement the forming assemblies 5-n form a front face of the wall section 2; and a rear face of the cast-in-place wall W is defined by a sidewall of the trench T. Alternatively, a separate forming member could be provided to form the rear face of the mould cavity 4. The wall sections 2 are each higher than the individua l forming assemblies 5- n. To achieve the desired height the forming assemblies 5-n are arranged in at least first and second rows R 1 , R2 to form the support wall 6. T he first row R 1 is formed by mounting a series of the support arm assemblies 1 1 -n mounted to the uprights 10. The first and second forming assemblies 5-1 , 5-2 are mounted to the support arm assemblies 1 1 -n to form the support wall 6. A first side of the wall section 2 is defined by an adjacent wall section 2 and/or a sidewall of the trench T. The third forming assemblies 5-3 also mounted to the support arm assemblies 1 1 -n to define a second end of the wall section 2. The first, second and third forming assemblies 5-1 , 5- 2, 5-3 connect together to form the first row R 1 of the support wall 6. One or more connecting pieces (spigots) may optionally be provided between the first, second and third forming assemblies 5-1 , 5-2, 5-3 to connect the adjacent first second and third forming plates 20-1 , 20- 2, 20-3. The first row R 1 forms an initial mould cavity 4. A first concrete pouring operation is then performed to introduce concrete C into the mould cavity 4. The mould cavity 4 is at least partially filled with the concrete C in the first concrete pouring operation. An operator can ensure that the mould cavity 4 is filled with concrete C during the first concrete pouring operation avoiding the formation of voids or cavities which may compromise the strength of the wall section 2.

A second row R 2 of said first second and third forming assemblies 5-1 , 5-2, 5-3 is then formed on top of the first row R 1. The first, second and third forming assemblies 5-1 , 5-2, 5-3 in the second row R2 connect to each other and also to the first second and third forming assemblies 5-1 , 5-2, 5-3 in the first row R 1 . The aforementioned one or more connecting pieces (spigots) may optionally also connect the first, second and third forming assemblies 5-1 , 5-2, 5-3 in the first and second rows R 1 , R2. The addition of the second row R2 increases the vertical height of the mould cavity 4. A second concrete pouring operation is then performed at least partially to fill the extended mould cavity 4 with concrete C. The alternating sequence of forming a row R n and filling the mould cavity 4 is repeated until the wall section 2 is complete. The concrete C is then allowed at least partially to cure until the wall section 2 is self-supporting. T he third forming assemblies 5- 3 may then be removed to expose a side wall of the wall section 2. The first and second forming assemblies 5-1 , 5-2 may optionally also be removed, or they may be left in situ to provide additional support. T he next wa ll section 2 may then be formed alongside the wall section 2 using the process described herein.

T he apparatus 1 described herein enables the forming assemblies 5-n to be arranged to form the rows R n relatively quickly, helping to ensure that the concrete C poured during consecutive pouring operations can combine to form a contiguous structure. F urthermore, at least in certain embodiments, the apparatus 1 may provide a safe working environment by creating accessible corridors around the perimeter of the excavation.

A modified arrangement of the third forming assembly 5-3 is shown in F igure 5. The third forming assembly 5-3 is configured to form at least one interlocking feature in the vertical side wall of the wall section 2. In particular, the third forming plate 20-3 comprises interlock forming means 36 for forming an interlocking (or keyed) feature in a side wall of the wall section 2. T he interlock forming means 36 in the present embodiment comprises a concave section in the form of an elongated channel. The elongated channel 36 extends substantially vertically and, in use, forms a vertical channel in the side wall of the wall section 2. T he elongated channel 36 has a positive draft angle to facilitate removal of the third forming assembly 5-3 after the wall section 2 has been formed. In the present embodiment the elongated channel 36 has a substantially rectangular or trapezoidal profile, but other configurations are also contemplated. As outlined above, the vertical side wall of each wall section 2 may define a side of the mould cavity 4 when an adjacent wall section 2 is cast. By forming at least one interlocking feature in the side wall, adjacent wall sections 2 may interlock with each other. T his interlocking may inhibit out-of-plane movements of the adjacent wall sections 2. At least in certain embodiments, this may improve the strength of the resulting cast-in-place wall W. The elongated channel 36 is illustrated as having a uniform profile in a longitudinal direction. In a variant, the elongated channel 36 may have a non-uniform profile in said longitudinal direction, for example comprising a first longitudinally tapered section and/or a second longitudinally tapered section. T he first and second longitudinally tapered sections may taper in the same direction or in opposite directions. The resulting interlocking of the adjacentwall sections 2 may inhibit relative movement in a vertical direction. Alternatively, or in addition, the third forming plate 20-3 may comprise a convex channel (not shown). The third forming assembly 5-3 may be handed, for example to form a first variant for forming a left-hand end wall of the wall section 2 and a second variant for forming a right hand end wall of the wall section 2.

A modified arrangement of the third forming assembly 5-3 is shown in F igure 6. In this variant the interlock forming means comprises a convex section in the form of an elongated channel. T he method and apparatus of forming interlocking features in the wall sections 2 making up a cast-in- place wall W is believed to be patentable independently. As shown in Figure 6, the modified arrangement of the third forming assembly 5-3 is also configured to support one or more reinforcing members 37, such as a reinforcing steel bar (also referred to as a rebar). In particular, the third forming assembly 5-3 is arranged to support the reinforcing member 37 in a substantially horizontal orientation during casting of the wall section 2. A support aperture 38 is formed in the first end plate 32 for receiving the reinforcing member 37. In the illustrated arrangement the support aperture 38 is formed in the elongated channel 36 of the first end plate 32. An end of the reinforcing member 37 could be located in the support aperture 38 such that the reinforcing member 37 is located within the wall section 2. Alternatively, the reinforcing member 37 may be positioned such that an end thereof projects out of the mould cavity 4. Thus, when the wall section 2 is cast, the reinforcing member 37 extends out of side wall of the wall section 2 and can be embedded within an adjacent wall section 2 (formed in a subsequent casting process). T his arrangement may help to reinforce the joint between adjacent wall sections 2. The method and apparatus of supporting the reinforcing member 37 during the casting process is believed to be patentable independently.

T he apparatus 1 according to the present embodiment is also suitable for forming a cast-in-place wall W comprising a plurality of wall sections 2 in the form of vertical pins (columns). T he wall sections 2 each have substantially the same width as the first forming assembly 5-1 . The formation of the wall sections 2 using a plurality of said first forming assemblies 5-1 will now be described with reference to F igures 7A-F . A foundation (also known as a toe) F is formed from concrete which is cast in situ, for example at the base of a trench T. A kick is then formed on the foundation F to provide a base for the wall section 2. The kick may be cast in place, for example by assembling a form box in the required position on the foundation F. One or more steel reinforcing bars (not shown) may be installed in the kick so as to extend upwardly from an upper surface thereof. T he wall section 2 is formed on top of the kick using the forming assemblies 5-1. T he form box may be used to provide support for one or more of the first forming assemblies 5-1 in the first row R 1 , for example to prevent or reduce deformation when the concrete C is poured into the mould cavity 4. In the present embodiment, the kick has substantially the same width as the wall section 2.

T he support assembly 7 is installed in the trench T by mounting the uprights 10 in a substantially vertical position. The uprights 10 in the present embodiment are self-supporting and are installed offsetfrom the desired location of the wall section 2, for example on the opposite side of the trench T. As shown in F igure 7A, one of the first forming assemblies 5-1 is supported by four (4) of said first support arm assemblies 1 1 -1 supported by respective first and second uprights 10. The first support arm assemblies 1 1 -1 extend substantially horizontally across the trench T when engaged. T he first forming assembly 5-1 forms a mould cavity 4. The mould cavity 4 has a height of approximately 600mm, corresponding to the height of the first forming assembly 5-1. In the illustrated arrangement, the first forming assembly 5-1 forms a front face of the wall section 2; and a rear face of the cast-in-place wall W is defined by a sidewall of the trench T. R einforcement bars are now installed at a full height for the wall section 2. A first concrete pouring operation is then performed to introduce concrete C into the mould cavity 4. The concrete C can be poured in a controlled manner with visual access to the mould cavity 4. The concrete C is poured around the reinforcement bars which are disposed in the mould cavity 4.

As shown in F igure 7B, a second row R2 comprising one of said first forming assemblies 5-2 is then formed on top of the first row R 1. T he first forming assembly 5-2 in the second row R2 connects to the first forming assembly 5-1 in the first row R 1. The addition of the second row R 2 increases the vertical height of the mould cavity 4. T he first forming assembly 5-2 in the second row R2 is supported by four (4) of said first support arm assemblies 1 1 -2 supported by respective first and second uprights 10. In the present embodiment, the mould cavity 4 has a height of approximately 1200mm when said second row R2 is added. A second concrete pouring operation is then performed to fill the extended mould cavity 4 with concrete C . The second row R 2 is assembled and the second concrete pouring operation performed before the concrete C poured during the first concrete pouring operation has cured. At least some of the concrete C introduced into the mould cavity 4 during a pouring operation may be mixed with some of the concrete poured during the previous pouring operation. As shown in F igure 7C, a third row R3 comprising one of said first forming assemblies 5-3 is then formed on top of the second row R2. The first forming assembly 5-3 in the third row R3 connects to the second forming assembly 5-2 in the second row R2. The addition of the second row R2 increases the vertical height of the mould cavity 4. T he first forming assembly 5-3 in the third row R3 is supported by four (4) of said first support arm assemblies 1 1 -3 supported by respective first and second uprights 10. In the present embodiment, the mould cavity 4 has a height of approximately 1800mm when said third row R 3 is added. A third concrete pouring operation is then performed to fill the extended mould cavity 4 with concrete C. T he third row R3 is assembled and the third concrete pouring operation performed before the concrete C poured during the second concrete pouring operation has cured.

As shown in Figure 7D, the process is repeated to add the fourth row R4 comprising one of said first forming assemblies 5-4 and a fourth concrete pouring operation performed. The first forming assembly 5-4 in the fourth row R4 is supported by four (4) of said first support arm assemblies 1 1 -4. In the present embodiment, the mould cavity 4 has a height of approximately 2400mm when said fourth row R4 is added. As shown in F igure 7E , the process is repeated to add the fifth row R 5 comprising one of said first forming assemblies 5-5 and a fifth concrete pouring operation performed. The first forming assembly 5-5 in the fifth row R 5 is supported by four (4) of said first support arm assemblies 1 1 -5. In the present embodiment, the mould cavity 4 has a height of approximately 3000mm when said fifth row R5 is added. This process is repeated, as required, to achieve the desired height of the wall W. T he concrete C is then allowed to cure in the mould cavity 4.

As shown in F igure 7F, once the concrete C has cured, the first forming assemblies 5-1 to 5-5 are removed along with the of first support arm assemblies 1 1 -1 to 1 1 -5. One or more fixed cross- members 40 may be mounted to the uprights 10 to brace the top of the wall section 2. T he process is then repeated to form a second wall section 2 adjacent to the first wall section 2. T he cast-in- place wall W comprises a plurality of said wall sections 2, the wall sections 2 each being formed in multiple stages.

In a variant of the present invention may be used to form wall sections 2 adjacent to each other. T he first forming assembly 5-1 forms a first mould cavity 4 for forming a first wall section 2. A partitioning member in the form of an end plate is installed to close a one wall of the first mould cavity 4. A first concrete pouring operation is performed to introduce concrete C into the first mould cavity 4. A second mould cavity 4 is formed alongside the first mould cavity 4. The partitioning member is disposed between the firstand second mould cavities 4. A second concrete pouring operation is then performed to fill the second mould cavity 4 with concrete C . The partitioning member is then removed from between the first and second mould cavities. T he removal of the partitioning member connects the first and second mould cavities. At least in certain embodiments, the partitioning member is removed before the concrete C cures, thereby allowing mixing of the concrete C at the interface between the first and second mould cavities. T his mixing can increase structural integrity of the cast-in-place wall W. T he partitioning member may be removed by displacing it upwardly from the top of the mould cavities 4. In a variant, a vertical slot may be formed in the forming assemblies 20-n to arrange removal of the partitioning member in a non-vertical direction (for example horizontally).

It will be appreciated that various modifications may be made to the embodiment(s) described herein without departing from the scope of the appended claims.

T he method and apparatus 1 described herein have focused on the forming of wall sections 2 alongside each other. The apparatus 1 described herein may be modified to enable the wall sections 2 to be formed on top of each other. A forming assembly 5-n could be configured to extend at least partially over the top of the mould cavity 4. T he forming assembly 5-n may comprise a forming plate 20-n which extends over the top of the mould cavity 4. In use, the additional forming assembly 5-n could define an upper surface of the wall section 2. T he forming assembly 5-n could comprise one or more projections and/or one or more recesses for forming interlocking feature(s) in the upper surface of the wall section. Alternatively, or in addition, the forming assembly 5-n may be configured to support one or more reinforcing members to extend between the wall sections 2. F or example, the forming assembly 5-n could support one or more reinforcing members in a substantially vertical orientation. The reinforcing members could be supported by a forming assembly 5-n configured to extend over at least a portion of the top of the mould cavity 4.

T he apparatus 1 described herein comprises first and second forming assemblies 5-1 , 5-2 having cooperating features which can interconnect adjacent first and second forming assemblies 5-1 , 5-2. In a modified arrangement, the first forming assembly 5-1 may have male and female connectors disposed at opposing ends thereof for cooperating with a like first forming assembly 5-1 . A male connector may be provided at a first end of the first forming assembly 5-1 and a female connector may be provided at a second end of the first forming assembly 5-1 , the male and female connectors having cooperating features. A plurality of like first forming assemblies 5- 1 may be connected to each other, for example to form one of said rows R n. A false floor could be supported by the support arm assemblies 1 1 -n, for example to facilitate the introduction of concrete into the mould cavity 4 as the rows of forming plates 5-m increase. T he height of the false floor could be adjustable. For example, a lift mechanism may be provided selectively to raise and lower the false floor. T he lift mechanism may be mounted to the uprights 10 or the support arm assemblies 1 1 -n.

T he forming assemblies 5-n may be coupled to the support arm assemblies 1 1 -n. F or example, the forming assemblies 5-n may be pivotally mounted to the support arm assemblies 1 1 -n. In this arrangement, the forming assemblies 5-n may be pivoted when the support arm assemblies 1 1 - n are raised so as not to obstruct the trench T. The forming assemblies 5-n may be pivoted to an operative position when the support arm assemblies 1 1 -n are lowered. A locking mechanism may be provided to lock the forming assemblies 5-n in an operative position.

T he apparatus 1 described herein could be used to support one or more cast-in apparatus as forming the wall section(s) 2 is formed. T he cast-in apparatus may, for example, comprise a bracket or mounting device. The cast-in apparatus may be supported by one or more of the support arm assemblies 1 1 -n during formation of the wall section 2. The cast-in apparatus may be held stationary during by the one or more support arm assemblies 1 1 -n for accurate location in the cast-in-place wall W.

A further embodiment of the apparatus 1 according to the present invention will now be described with reference to F igures 8A to 8M. The apparatus 1 is a development of the earlier embodiments described herein. Like reference numerals are used for like components.

T he apparatus 1 in the present embodiment is configured to form a cast-in-place wall W of a lightwell LW. The cast-in-place wall W is formed simultaneously with the excavation of a shaft s H to form the lightwell LW. The cast-in-place wall W in the illustrated arrangement forms a retaining wall of the lightwell LW, but it will be understood that the method and apparatus may be used in other applications. For example, the apparatus 1 may be used to form a retaining wall of a trench.

T he cast-in-place wall W is cast in-situ (i.e. on-site) and forms a load-bearing structural component. T he cast-in-place wall W is formed from a cementitious material, which in the present embodiment is concrete C . T he cast-in-place wall W comprises a plurality of said wall sections 2. T he wall sections 2 each extend around at least partway around the perimeter of the lightwell LW. T hus, in the present embodiment, the wall sections 2 extend horizontally. T he wall sections 2 are formed one above the other to form the cast-in-place wall W which defines the lightwell LW. The wall sections 2 may interlock with adjacent wall sections 2 or may be connected to each other by one or more reinforcing members.

T he apparatus 1 is assembled to form a support wa ll 3 which operatively defines at least a portion of a mould cavity 4 into which concrete C is poured to form the cast-in-place wall W. The apparatus 1 comprises a plurality of forming assemblies 5-n and a support assembly (denoted generally by the reference numeral 7). The forming assemblies 5-n each comprise a forming plate 20-1 which combine to form a support wall 6 which defines at least one wall of the mould cavity 4. T he forming assemblies 5-n and the support assembly 7 in the present embodiment are fabricated from steel. T he forming assemblies 5-n are operatively arranged in a series of rows R n, each of said rows R n comprising one or more of said forming assemblies 5-n. Unlike the earlier embodiments described herein, the rows R n are assembled consecutively below each other as the lightwell LW is excavated. The mould cavity 4 is created between the support wall 6 and the sidewall of the excavated shaft S H. Concrete C is poured into the mould cavity 4 to form the wall section 2. The next row R n is assembled below the existing row R n to form the support wall 6 at a lower position in the shaft S H. C oncrete C is introduced into the mould cavity 4 to form the next wall section 2 disposed below the previously formed wall section 2. The process is repeated as the lightwell LW is excavated to form the shaft S H to the desired depth. T he forming assemblies 5-n are configured to be removable from the wall section 2 once the concrete C has cured. For example, those features of the forming assemblies 5-n that contact the concrete C are formed without negative draft angles.

T he support assembly 7 is configured to support the forming assemblies 5-n. T he support assembly 7 comprises at least one upright 10 and a plurality of support arm assemblies 1 1 -n. In use, the upright(s) 10 extends substantially vertically and is fixedly mounted in position. In the present embodiment, the at least one upright 10 comprises a pile or other member which is driven into the ground. The uprights 10 comprise a plurality of apertures for mounting the support arm assemblies 1 1 -n. The apertures in the uprights 10 are equally spaced apart and are provided along the length of the uprights 10 to allow adjustment of the vertical position of the support arm assemblies 1 1 -n. T he support arm assemblies 1 1 -n are mounted to the at least one upright 10. T he upright 10 is driven vertically into the ground before excavation of the lightwell LW. In the illustrated arrangement, two of said uprights 10 are driven into a central location in the lightwell LW. In a variant, the uprights 10 may be disposed coincident with a corner of the lightwell LW. Alternatively, or in addition, the uprights 10 may be disposed coincident with a sidewall of the lightwell LW. The forming plates 20-n may be mounted directly to the uprights 10.

T he support arm assemblies 1 1 -n each comprise a mounting bracket 12-n, a support arm 13-n and a mounting head 14-n. The mounting brackets 12-n comprise first and second T-shaped brackets 15-n suitable for positioning on opposing sides of the uprights 10. The T-shaped brackets 15-n each have two (2) apertures which align with the apertures provided in the uprights 10. T he mounting brackets 12-n are fastened to the uprights 10 using suitable mechanical fasteners (not shown), for example by aligning the apertures in the T-shaped brackets 15-n and the apertures in the uprights 10 and inserting a clevis pin or bolt The forming assemblies 5-n are connected to the mounting heads 14-n using suitable mechanical fasteners, such as a clevis pin and clip arrangement. The length of the support arms 13-n is adjustable to allow the distance between the uprights 10 and the intended location of the support wall 6 to be adjusted. In the present embodiment, the mounting heads 14-n comprise a threaded member 17 having a male thread which is received in a cooperating threaded member (not shown) having a female thread which is mounted to the support arms 13-n.

T he support wall 6 is composed of a plurality of the forming assemblies 5-n arranged in one or more rows R n. E ach row R n comprises at least one of the forming assemblies 5-n. As described herein, the forming assemblies 5-n are configured to interconnect with the forming assemblies 5- n in the row R n above and/or below. T he method of using the apparatus 1 will now be described in more detail.

As shown in F igure 8A, a first ground excavation operation is performed to form a shaft S H to form the lightwell LW. A guard rail is installed around the shaft S H. T he uprights 10 are driven into the ground so as to extend at least substantially vertically. As shown in Figure 8B, first and second uprights 10 are driven into the ground substantially parallel to each other. A first row R 1 of the forming assemblies 5-1 is installed. As shown in F igure 8C, one of the forming assemblies 5-1 is supported by four (4) of said first support arm assemblies 1 1 -1 supported by respective first and second uprights 10. The first support arm assemblies 1 1 -1 extend substantially horizontally within the shaft S H. T he forming assembly 5-1 forms a mould cavity 4. T he mould cavity 4 has a height of approximately 600mm, corresponding to the height of the forming assembly 5-1. In the illustrated arrangement, the forming assembly 5-1 forms an inner face of the wall section 2. A lower surface of the wall section 2 may optionally be formed by a lower forming panel (not shown). T he lower forming panel may, for example, extend substantially horizontally. The lower forming panel may optionally be profiled to form one or more features in the wall section 2 for interlocking with an adjacent wall section. Alternatively, or in addition, a side of the wa ll section 2 may be formed by a side forming panel (not shown). The side forming panel may, for example, extend substantially vertically. The side forming panel may optionally be profiled to form one or more features in the wall section 2 for interlocking with an adjacent wall section. The lower forming panel and/or the side forming panel may be integral with the forming plates 20-1 or may be removably mounted to the forming plate 20-1.

An outer face of the cast-in-place wall W is defined by a sidewall of the shaft S H. R einforcement bars may optionally be supported in the mould cavity 4. A first concrete pouring operation is then performed to introduce concrete C into the mould cavity 4 to form a first wall section 2, as shown in F igure 8D. T he concrete C can be poured in a controlled manner while enabling visual inspection of the mould cavity 4. The concrete C may be poured around the reinforcement bars which are disposed in the mould cavity 4. In the present embodiment, the first row R 1 is arranged to form a rectangular frame extending around the perimeter of the shaft S H. T he concrete C in the mould cavity 4 is then allowed to cure. In the present embodiment, the forming assemblies 5- 1 are removed after the concrete C has cured to provide improved access, thereby facilitating excavation of the shaft S H. In a variant, the forming assemblies 5-1 in the first row R 1 may be left in place.

After the concrete C has cured, a second ground excavation operation is performed to extend the shaft S H. As shown in F igure 8E , a second row R2 of said forming assemblies 5-2 is then assembled in the extended shaft s H. T he second row R2 is assembled below the level of the first row R 1. The second row R2 comprises a plurality of said forming assemblies 5-2. T he addition of the second row R2 forms a mould cavity 4 below the wall section 2 formed by the first row R 1. T he forming assemblies 5-2 in the second row R 2 are supported by four (4) of said first support arm assemblies 1 1 -2 supported by the first and second uprights 10. A second concrete pouring operation is then performed to fill the mould cavity 4 formed by the second row R 2 to form a second wall section 2. In order to support the first wall section 2, the forming assemblies 5-2 in the second row R2 may be installed in a staggered sequence. For example, forming assemblies 5-2 may be installed to form the second row R2 in two or more stages. A first set of opposing walls may be formed in a first stage; and a second set of opposing walls formed in a second stage. In the present embodiment, the second wall section 2 is assembled in first and second stages to form opposing first and second L-shaped portions of the second wall section 2. The first L-shaped wall portion is formed and the concrete C allowed to cure. As shown in F igure 8F, additional forming assemblies 5-1 are assembled and the second L-shaped portion is formed to complete the second wall section 2. Alternatively, or in addition, the forming assemblies 5-1 in the first row R 1 may be configured to support the wall W. For example, the forming plates 20-1 may comprise a concave portion and/or a convex portion which supports the cast section of the wall W once the concrete C has cured. The wall section 2 formed by the second row R2 of the forming assemblies 5-2 is shown in F igure 8G . As shown in Figure 8H, a third row R3 comprising at least one of said forming assemblies 5-3 is then assembled to form a third wall section 2 below the second wall section 2. The process of forming the third row R3 is the same as that described above for the second row R 2. The process of forming the rows R n is repeated until the lightwell LW is the desired depth. As illustrated in F igures 81, a fourth row R4 is assembled using the same process to form a fourth wall section R4. T he formation of a fifth row R 5 in staggered first and second stages to form a fifth section R 5 is illustrated in F igures 8J and 8K. The first stage comprises forming a first portion of the fifth wall section 2; and the second stage comprises forming a second portion of the fifth wall section 2. T he concrete C in the first portion is allowed to cure before the second portion is formed in order to support the above wall sections 2. The completed lightwell LW is illustrated in F igure 8L with the forming assemblies 5-5 in place. In the present embodiment, the lightwell LW comprises five (5) wall sections 2 disposed one above the other. It will be understood that the lightwell LW may comprise less than or more than five (5) of said wa ll sections 2. When the concrete C has cured, the forming assemblies 5-5 in the fifth row R 5 are then removed, as shown in F igure 8M.

In a variant of the embodiment described herein with reference to F igures 8A and 8M, the forming assemblies 5-n may be used as shoring assemblies while the shaft s H is excavated. The forming plates 20-n may be used as shoring plates to maintain the integrity of the shaft S H during excavation. T he forming assemblies 5-n may subsequently be used to form the cast-in-situ wall W. For example, the wall sections 2 may be formed progressively from the bottom to the top of the shaft S H. T he forming plates 20-1 may, for example, be removed consecutively from the bottom to the top of the shaft s H as the cast-in-place wall W is formed. The method may comprise using the forming assemblies 5-n to shore the shaft S H during excavation; and then to form the cast-in-place wall W.

In a further variant of the embodiment described herein with reference to F igures 8A and 8M, the shaft S H may be excavated; and the forming plates 20-n then used to form the cast-in-situ wall W. The shaft s H may be excavated using conventional excavation techniques. T he forming plates 20-n may subsequently be used to form the cast-in-situ wall W in accordance with the techniques described herein. The mould cavity 4 is created between the support wall 6 and the sidewall of the excavated shaft S H. For example, the wall sections 2 may be formed progressively from the bottom of the shafts H to the top of the shafts H. One or more preformed member may be installed in the shaft S H prior to using the forming plates 20-n to form the cast-in-situ wall W. In this arrangement, the cast-in-situ wall W may be used to form a lining for the shaft S H. For example, the cast-in-situ wall W may provide a liner for the shaft S H. T he mould cavity 4 may be created between the support wall 6 and the one or more preformed member installed in the shaft S H.

T he present embodiment has been described with reference to a lightwell LW comprising a shaft S H which is illustrated as extending vertically. It will be understood that the techniques described herein may be used in applications where the shaft S H does not extend vertically. Indeed, the shaft S H forms a tunnel which may, for example, extend substantially horizontally or may be inclined at an acute angle relative to the horizontal. The forming plates 20-n could conceivably be used as shoring members during excavation of the tunnel and subsequently as forming plates to form the cast-in-situ wall W. Alternatively, preformed members may be installed to provide structural support for the tunnel and the forming plates 20-n used to form the cast-in-situ wall W inside the preformed members. T he forming plates 20-n may be assembled into at least first and second rows R n which are offset from each other in a longitudinal direction along the length of the tunnel. The first and second rows R n may be used to form respective first and second wall sections which are disposed adjacent to each other. The forming plates 20-n may be assembled into the first row R n so as to extend around at least a portion of the inner circumference of the tunnel. T he first row R n may thereby form an annular first mould cavity into which concrete may be poured in a first casting operation to form a first wall section. A partitioning member may be provided to close the first row R n. T he partitioning member may be in the form of an annular end wall. T he annular end wall is assembled to close the assembled annular mould cavity. For example, one or more side forming panel may be installed to close the annular mould cavity. At least in certain embodiments, the side forming panel may be configured to form at least one feature in the first wall section for cooperating with the second wall section. The at least one feature may optionally be configured to interlock with the second wall section. The at least one feature may comprise a projection and/or a recess for cooperating with the second wall section when the second wall section is formed. In use, the forming plates 20-n may be assembled into a second row R n which extends around the inner circumference of the tunnel to form an annular second mould cavity adjacent to the first wall section. The second mould cavity is formed such that a section of the firstwall section comprising said at least one feature defines a portion of the second mould cavity. When the second wall section is cast, the resulting structure cooperates with the at least one feature formed in the first wall section. T hus, the first and second wall sections cooperate with each other, for example to form a joint. The joint may be in the form of an overlapping joint which may be suitable for suppressing or inhibiting water penetration between the wall sections (also known as a water joint). The features formed in the first and second wall sections may be keyed, for example to form a dovetail joint, for controlling relative movement of the first and second wall sections in a lateral and/or vertical direction. This process may be repeated for a series of wall sections formed along the tunnel.

In a further variant the forming plates 20-n may be assembled into a first row R n which extends around a portion of the inner circumference of the tunnel. T he first row R n may form a part-annular first mould cavity into which concrete may be poured in a first casting operation to form a first wall section. The first mould cavity may, for example, consist of a segment, a quadrant or a semicircle. The forming plates 20-n may be assembled into a second row R n which is disposed on top of the first row R n. The second row R n may extend around a portion of the inner circumference of the tunnel. Thus, in use, a plurality of said rows R n may be combined to form an annular mould cavity. A separate pouring operation may be performed after assembly of each row R n in accordance with the teaching herein. In the arrangement illustrated in F igures 8A-8M, the shaft s H is illustrated as having a rectangular cross-section. It will be understood that the shaft S H may have different shapes or profiles. The shaft s H could, for example, be circular or elliptical in cross-section. The shaft S H could comprise a polygon having less than four (4) sidewalls or greater than four (4) sidewalls. The forming plates 20-n may, for example, comprise a curved or arcuate forming surface for forming the curved sidewa ll of the shaft s H. The shaft s H may be formed in a series of sectors or quadrants. A single upright 10 may be installed along a central longitudinal axis of the shaft s H to support the forming plates 20-n. T he shaft s H could have a central axis which extends horizontally or which is inclined relative to a horizontal plane, for example to form an inclined tunnel or other shaft. The shaft S H described herein comprises a closed perimeter. It will be understood that the same techniques may be used to form a wall in an embankment or the like, for example by excavating material to one side of the wall as it is formed.

It will be understood that the techniques described herein to support at least one reinforcing member within the mould cavities may also be applicable in the forming of a cast-in-place wall W in a tunnel. For example, the at least one reinforcing member may be supported such that a portion thereof extends out of the first wall section for integration into the second wall section.

As described herein, concrete (or other curable material) is poured into the mould cavity formed by the forming plates 20-n. The concrete comes into direct contact with the forming plates 20-n and is allowed to cure. T he concrete may become attached to the surface of the forming plates 20-n and this may cause damage to the forming plates 20-n, for example when the forming plates 20-n are removed. A protective liner may be provided to protect the forming plates 20-n. The protective liner may, for example, be provided over a major surface of the forming plates 20-n which faces into the mould cavity. By way of example, the protective liner may comprise a flexible membrane which is provided over the forming plates 20-n prior to performing a pouring operation to introduce the concrete into the mould cavity. By providing the protective liner, the forming plates 20-n may be removed more readily once the concrete has cured. The protective liner may be attached to the forming plates 20-n and, if required, repaired or replaced. Alternatively, the protective liner may be supported by the forming plates 20-n without being attached thereto. The protective liner may become attached to the surface of the concrete after the forming plates 20-n are removed. In this scenario, the protective liner may be removed in a separate operation. In certain embodiments, the protective liner may be integrated into the cast-in-place wall W. The protective liner may comprise fastening means, for example in the form of a male connector and/or a female connector. The fastening means may cooperate with the concrete C to fasten the protective liner to a face of the cast-in-place wall W. The integration of the protective liner with the cast-in-place wall W is believed to be patentable independently. A further variant of the method and apparatus according to the present invention will now be described with reference to F igures 9A and 9B. Like reference numerals are used for like components. In the present embodiment, the apparatus 1 is configured to integrate a water impermeable layer 41 into the cast-in-place wall W, as shown in F igures 9A and 9B. In use, the water impermeable layer 41 is suitable for inhibiting the ingress of water into the cast-in-place wall W. The water impermeable layer 41 forms an integrated waterproof layer. The water impermeable layer 41 forms an integral waterproof layer and has particular in the formation of basements and other structures where the ingress of water should be suppressed or inhibited. T he apparatus and associated method may be used to provide waterproof tanking for the cast-in-place wall W. The water impermeable layer 41 is composed of a plurality of panel members 42 which are preformed. T he panel members 42 are composed of a plastics material, such as polyvinylchloride (PVC ). In the present embodiment, the panel members 42 have a substantially rigid composition. It will be appreciated that the panel members 42 may have flexible or resilient compositions in other embodiments.

T he panel members 42 each comprise a panel 43 which is substantially planar. The panels 43 in the present embodiment each have a thickness of approximately 5mm. The panels 43 each have opposing first and second surfaces 44-1 , 44-2. The first surface 44-1 is configured to be positioned against (or proximal to) the major surface of the forming plates 20-n. The second surface 44-2 is configured to face away from the forming plates 20-n into the mould cavity. In the present embodiment, the panel members 42 each comprise anchoring means for anchoring the panel members 42 to the cast-in-place wall. T he anchoring means in the present embodiment comprises a plurality of anchor members 45 disposed on the panel 43. The anchor members 45 may, for example, be disposed around a perimeter of each panel 43, inset from an edge thereof. T he anchor members 45 in the present embodiment each comprise a projection which extends outwardly relative to the second surface 44-2. T he anchor members 45 each comprise or consist of at least one anchor 47 for fastening the panel member 42 to the cast-in-place wall W. The anchor 47 may, for example, comprise a negative return angle to resist withdrawal of the anchor member 45. In the present embodiment, the anchor 47 is in the form of a head having an enlarged cross-section disposed at a distal end of the elongate body 46. In variants, the anchor 47 may, for example, comprise a lateral protrusion, an aperture or a reverse-inclined surface. T he anchor members 45 may be formed integrally with the panel 43. For example, the anchor members 45 may be moulded with the panel 43. Alternatively, the anchor members 45 may be formed separately and fastened to the panel 43. For example, the anchor members 45 may be bonded, welded or mechanically fastened to the panel 43. In a further variant, the anchor members 45 may be inserted through respective holes formed in the panel 43. The anchor members 45 may comprise an enlarged base to prevent them being pulled through the hole formed in the panel 43. T he anchor members 45 may comprise a cut-out or recess for engaging the second surface 44- 2 of the panel 43 to inhibit withdrawal, thereby fixing the anchor members 45 in position. The holes may be pre-formed in the panel 43. Alternatively, or in addition, the holes may be formed after positioning the panel member 42 againstthe forming plate 20-n. T he forming plate 20-n may, for example, comprise a series of apertures to provide the required access.

T he panel members 42 in the present embodiment each comprise joint forming means 48 for forming a joint with a like panel member 42 disposed adjacent thereto. The joint forming means 48 in the present embodiment comprises an overlap member49 disposed along one edge thereof. T he overlap member 49 is arranged to overlap a portion of the adjacent panel member 42 to form a lap joint (also known as an overlap joint). A sealant 50 is provided between the overlap member 49 and the firstsurface 44-1 of the adjacent panel member 42 to form a seal between the adjacent panel members 42. The sealant 50 may comprise an adhesive, bonding agent or filler. In the arrangement illustrated in F igure 9B, the overlap member 49 is configured to be positioned in contact with the first surface 44-1 of the adjacent panel member 42. T his arrangement of the overlap member 49 provides access to facilitate introduction of the sealant 50. In a variant the overlap member 49 may be configured to be positioned in contact with the second surface 44-2 of the adjacent panel member 42. This arrangement would provide a substantially planar outer surface formed by the panel members 42. T he sealant 50 may be introduced into the exposed region between the panels 43. In a further variant, the panel members 42 may be arranged to butt against each other to form a butt joint. Other configurations of the overlap member 49 are also contemplated to form the joint forming means 48. Alternatively, or in addition, a strip of a sealing material may be provided over the joint.

T he use of the panel members 42 will now be described with reference to F igure 9. T he support assembly 7 is installed by mounting the uprights 10 in a substantially vertical position. A first forming assembly 5-1 is supported by first support arm assemblies 1 1 -1 supported by respective first and second uprights 10. The first forming assembly 5-1 forms a first mould cavity 4. In the illustrated arrangement the first forming assembly 5-1 forms a front face of the cast-in-place wall W. The panel members 42 are then fitted to the first forming assembly 5-1 . In particular, the panel members 42 are mounted to the front of the forming plates 20-n. The panel members 42 may be held in position using a suitable mechanical fastener or clip. The panel members 42 are arranged such that the anchor members 45 extend inwardly into the mould cavity 4. T he panel members 42 are installed in sequence such that the overlap member 49 of each panel member 42 overlaps a portion of the adjacent panel member 42. A first concrete pouring operation is then performed to introduce concrete C into the mould cavity 4. T he concrete C fills the mould cavity 4 and the anchor members 45 are at least partially embedded in the concrete C. The concrete C cures around and the at least one anchor 47, thereby anchoring the anchor members 45 within the concrete. T he anchor members 45 are operable to permanently fasten the panel members 42 to the cast-in-place wall W. After the concrete C has cured, the forming plates 20-n may be released from the panel members 42. The panel members 42 are anchored to the cast-in-place wall W by virtue of the anchor members 45 which are embedded in the cured concrete C . The sealant 50 is then applied between the overlap member 49 and the first surface 44-1 to form a seal. T he panel members 42 collectively form the water impermeable layer 41. It will be understood that the water impermeable layer 41 is integrated with the cast-in-place wall W.

T he panel members 42 may be used in conjunction with the other aspects of the invention described herein. In particular, the panel members 42 may be utilised when the forming assemblies 5-n are assembled in a series of rows. T he panel members 42 can, for example, be mounted as each row is formed. E ach panel member 42 may be configured to cooperate with a like panel member 42 disposed in a row below. For example, the panel members 42 may each comprise a flange disposed along a lower edge to cooperate with an upper edge of the panel member 42 below. It will be understood that the formation of an integrated water impermeable layer 41 is not limited to implementation in which the forming assemblies 5-n are formed in multiple layers. By way of example, the panel members 42 could be used when the forming assemblies 5-n are assembled in a single row. In a further variant, the panel members 42 may be used in place of the forming plates 20-n. In this arrangement, the panel members 42 may be supported directly by the uprights 10 or the support arm assemblies 1 1 -1.

In a variant the anchoring means may comprise an aperture, for example in the form of a hole or recess, formed in the panel 43. The aperture may have a negative return angle to form an interlocking connection with the concrete C introduced into the mould cavity 4. F or example, the panel 43 may comprise a plurality of holes for forming a series of plugs of concrete to anchor the panel members 42 to the cast-in-place wall W. The apertures could be formed in a concave recess or cup formed in the panel 43 which project into the mould cavity 4. When the pouring operation is performed, the concrete C introduced into the mould cavity 4 may flow through the holes formed in the panel 43. T he forming plates 20-n disposed adjacent to the panel 43 prevent leakage of the concrete C from the mould cavity. When the concrete C has cured, the forming plates 20-n may be removed. T he exposed concrete plugs anchoring the panel members 42 to the cast-in-place wall W may be sealed or covered. T he panel members 42 may optionally comprise connecting means for forming a connection with an adjacent like panel member42. F or example, the panel members 42 may comprise interlocking male and female connectors for connecting adjacent panel members 42 having a like configuration. Alternatively, or in addition, the connecting means may be integrated into the overlap member 49. T he anchoring means may be provided on the overlap member 49 to cooperate with the section of the adjacent panel member 42 which is overlaid. F or example, the anchoring means may extend through one or more apertures formed in the adjacent panel member 42. The anchoring means may comprise a return or recess which engages with the second surface 44-2 of the panel member 42. Alternatively, the overlap member 49 may, for example, comprise one or more apertures for cooperating with the anchoring means of an adjacent like panel member 42. T he anchoring means may extend through one or more apertures formed in the overlap member 49. The anchoring means may comprise a return or recess which engages with an outer surface of the overlap member 49. At least in certain embodiments, the anchoring means may apply a clamping force to the overlap member 49 to improve the seal between the adjacent panel members 42.

T he anchor 47 may form a fastening plug for receiving a mechanical fastener, such as a screw. T he anchor 47 may comprise a fastener-receiving aperture for receiving a mechanical fastener. T he anchor 47 may be anchored to the cast-in-place wall W, as described herein. At least in certain embodiments, the anchor 47 may extend through the water impermeable layer 41. Thus, the anchor 47 may provide a fixing point without the need to form a separate hole in the water impermeable layer 41 .

A further variant is illustrated in F igures 10A and 10B. In this variant, the water impermeable layer 41 is formed by a flexible membrane 51 which may be supported by the forming plates 20-n prior to the concrete pouring operation. The flexible membrane 51 has opposing first and second surfaces 52-1 , 52-2. T he first surface 52-1 is configured to be positioned against (or proximal to) the major surface of the forming plates 20-n. The second surface 52-2 is configured to face away from the forming plates 20-n into the mould cavity 4.

T he flexible membrane 51 is anchored to the cast-in-place wall W by a plurality of anchor members 53. T he anchor members 53 each comprise at least one anchor 54 for fastening the flexible membrane 51 to the cast-in-place wall W. T he anchor 54 is displaced outwardly from the second surface 52-2 of the flexible membrane 51 such that in use, concrete C surrounds the anchor 54. T he anchor 54 is in the form of a head having an enlarged cross-section disposed at a distal end of an elongate body 55. In variants, the anchor 54 may, for example, comprise a lateral protrusion, an aperture or a reverse-inclined surface. T he anchor members 53 may be formed integrally with the flexible membrane 51 . For example, the anchor members 53 may be moulded with the flexible membrane 51. Alternatively, the anchor members 53 may be formed separately and fastened to the panel 43. As shown in F igure 10, the anchor members 53 may comprise a mounting portion 56 for locating in the flexible membrane 51. T he mounting portion 56 may form a fixing pointforfastening an object to the cast-in-place wall W. The mounting portion 56 may be configured to receive a mechanical fastener, such as a screw. For example, the mounting portion 56 may comprise a longitudinal aperture for receiving a mechanical fastener. T he longitudinal aperture may extend at least partway along the elongate body 55 to form a plug.

In the present embodiment, the anchor members 53 each comprise a connector 57 for connecting the flexible membrane 51 to the forming plates 20-n, as shown in F igure 10B. T he connector 57 comprises a frangible portion which is inserted through an aperture formed in the forming plates 20-n. An inner surface of the connector 57 engages an outer surface of the forming plates 20-n to retain the flexible membrane 51 in position. When the forming plates 20-n are to be removed, the frangible portion is removed to release the flexible membrane 51. A line of weakness or other frangible section may be formed in the anchor members 53 to facilitate removal of the connector 57. The removal of the frangible portion may optionally expose the fastener receiving aperture described herein.

It will be understood that a plurality of sections of the flexible membrane 51 may be used to form the water impermeable layer 41 . T he adjacent sections of the flexible membrane 51 may be arranged in an overlapping arrangementto form a lap joint. A sealant may be provided to seal the joint. T he sealant may, for example, comprise a waterproof tape which is adhered or thermally welded over the joint A variant of the method and apparatus described with reference to F igures 9A and 9B will now be described with reference to F igure 1 1. Like reference numerals are used for like components.

T he apparatus 1 is configured to integrate a first water impermeable layer 41 into the cast-in- place wall W. T he water impermeable layer 41 comprises a plurality of first panel members 42 arranged to form an integral waterproof layer and has particular in the formation of basements and other structures where the ingress of water should be suppressed or inhibited. T he apparatus and associated method may be used to provide waterproof tanking for the cast-in-place wall W. T he first panel members 42 are composed of a plastics material, such as polyvinylchloride (PVC), and have a substantially rigid composition. It will be understood that at least certain aspects of this variant may be incorporated into the arrangement described herein with reference to F igures 10A and 10B which utilises the aforementioned flexible membrane 51. T he first panel members 42 are fastened to an internal face of the cast-in-place wall W. As described herein, the first panel members 42 are fastened to the cast-in-place wall W by a plurality of anchor members 45. By casting the water impermeable Iayer 41 into a face of the cast-in-place wall W, there may be a reduced risk in hydro static pressure between the water impermeable layer 41 and the face of the cast-in-place wall W. The anchor members 45 may be formed integrally with the panel members 42; or the anchor members 45 may be formed as separate components which are fastened to the panel members 42. T he apparatus 1 in the present variant includes a second membrane 60. The second membrane 60 is spaced apart from the water impermeable layer 41 , thereby forming a cavity 61 between the water impermeable layer 41 and the second membrane 60. T he second membrane 60 in the present embodiment is also water impermeable. The second membrane 60 comprises a plurality of second panel members 62 arranged to form an inner wall 63 which is spaced apart from the cast-in-place wall W.

T he second panel members 62 are supported by a plurality of connecting members 64 which extend across the cavity 61. T he connecting members 64 each comprise a threaded member mounted to the water impermeable layer 41 . In the present embodiment, the anchor members 45 form anchor points for supporting the connecting members 64. T he anchor members 45 each comprise a threaded aperture (not shown) for receiving a first end of one of the connecting members 64. A second end of connecting members 64 is fastened to the second panel members 62. A clamp 65 is provided for mechanically fastening the connecting members 64 to the second panel members 62. The clamp 65 comprises a gasket 66, a cup member 67 and a mechanical fastener (such as a nut) 68 for cooperating with the second end of the connecting members 64. T he second panel members 62 are at least partially supported by the first panel members 42 via the connecting members 64. T he gasket 66 may, for example, comprise an O-ring for forming a fluid-tight seal. The gasket 66 in the present embodiment is part-conical. The clamp 65 illustrated in F igure 1 1 is positioned to secure an overlapping joint (a lap joint) formed between two adjacent second panel members 62. A plurality of the clamps 65 may be provided along the overlapping joint. A seal may be provided between the two second panel members 62. As shown in F igure 1 1 , a mounting bracket 69 is provided to support the periphery of the second membrane 60. T he mounting bracket 69 is mounted to an extension of the water impermeable layer 41 which in the illustrated arrangement extends horizontally over a section of floor. In the present embodiment the mounting bracket 69 is generally L-shaped and comprises first and second flanges (or spur) 70-1 , 70-2 for cooperating with the second panel member 62. The mounting bracket 69 comprises locking means 71 for securing the second panel member. The locking means 71 comprises at least one threaded member 72 (only one of which is shown in F igure 1 1 ) spaced apart along a longitudinal axis of the mounting bracket 69 (extending into the plane of the page in Figure 1 1 ). A closing member 73 is provided for mounting to the threaded members 72 to fasten the second panel members 62 in position. The closing member 73 in the present embodiment has a U-shaped profile and comprises first and second end seals 74-1 , 74- 2 for cooperating with the mounting bracket 69 to form a fluid-tight seal. A mechanical fastener (such as a nut) 75 is provided on each threaded member 72 to fasten the closing member 73 to the mounting bracket 69. A sealant may optionally be applied between the connecting members 64 and the mounting bracket 65. T he apparatus 1 may comprise mounting brackets 69 mounted to vertical walls and/or a ceiling to support the second membrane 60.

T he apparatus 1 may comprise a first port (not shown) for draining liquid from the cavity 61. If water does enter the cavity 61 , a pump may drain the collected water from the cavity 61 through the first port. T hus, a drain-off backup is provided for the cavity 61.

At least in certain embodiments, the cavity 61 formed between the first and second panel members 42, 62 may be at least substantially sealed. T hus, the cavity 61 may comprise a sealed or at least substantially sealed chamber. Alternatively, or in addition, the apparatus 1 may comprise a second port (not shown) for introducing a gas, typically air, into the cavity 61 to increase the pressure of the cavity 61 above atmospheric pressure. By testing the rate of change of an internal pressure of the cavity 61 , the seal established by the first and second panel members 42, 62 may be tested. This may enable testing of the apparatus 1 after it has been installed, for example to establish that the first and second panel members 42, 62 have been installed correctly. The test may be repeated periodically to check that the seals are still in place. As a further possibility, the pressure in the cavity 61 may be reduced to less than atmospheric pressure and then sealed. T he pressure may be reduced sufficiently to establish a partial vacuum in the cavity 61 . The reduced pressure in the cavity 61 may draw the opposing faces of the first and second panel members 42, 62.

A control system (not shown) may be provided to monitor the status of the cavity 61 , for example to perform self-testing. The control system may comprise a pressure monitor for monitoring an operating pressure in the cavity 61. The control system may thereby monitor an integrity of the seal(s) formed by the first and second panel members 42, 62. An alarm may be triggered if a detected operating pressure is outside a predefined threshold, for example indicating that a seal has failed. In the eventthatthe control system determines that a seal has failed, the second panel members 62 may be removed by releasing the clamp 65 and the locking means 71 to perform maintenance.

It will be understood that a plurality of the cavities 61 may be formed. For example, a plurality of cavities 61 may be associated with a single cast-in-place wall W. A first port and/or a second port may be provided in each cavity. T he control system may be configured to monitor an operating pressure of each of the cavities 61 . The control system may thereby isolate any system faults.

It will be appreciated that various modifications may be made to the embodiment(s) described herein without departing from the scope of the appended claims.

For example, the forming plates 20-n may each comprise a releasable clip or fastener for cooperating with an adjacent forming plate 20-n. The clip or fastener may be engaged to connect the adjacent forming pates 20-n, thereby increasing the strength of the forming assembly 5-n. Alternatively, or in addition, one or more reinforcing member may be incorporated into the forming plates 20-n.

T he method of forming the cast-in-place wall W described herein comprises multiple concrete pouring operations. However, it will be appreciated that the apparatus 1 described herein could also be employed to form a cast-in-place wall W using a single concrete pouring operation. The apparatus 1 is reconfigurable and the forming assemblies 5-n may provide a useful alternative to known forming structures.

T he forming plates 20-n have been described herein as being composed of sheet metal. It will be understood that the forming plates 20-n could be formed of other materials, such as wood, plywood, plastic, etc.