FIELD OF THE DISCLOSURE

The present disclosure relates to a pipe pile, pipe pile system and method of installation and manufacture of the same.

BACKGROUND OF THE DISCLOSURE

In many development sites, especially in dense urban environments, it may be necessary to have a deep excavation with an abrupt change between the natural ground level and the level of an excavated building pad. Retaining structures will be necessary to support the ground and prevent groundwater ingress during excavation.

One of the most commonly adopted retaining structures for such sites is a pipe pile system. Typical pipe pile systems comprise adjacent steel tubular pipe piles which are drilled into the ground. Lagging wall sections (plates) will need to be successively attached (often by welding) in layers between adjacent piles. This technique is especially common in places such as Hong Kong and other countries in Asia such as Japan, Singapore, etc., where basements of large buildings are be located very close to a site boundary.

In an effort to prevent a significant amount of water flowing into such sites, cementitious grout is typically introduced into the region behind the piles by drilling separate holes into which a grout pipe is inserted. Grout is pumped in the soil behind the piles to fill interstices and provides a “grout curtain”. This grout curtain is designed to impede the passage of water between the piles and into the basement excavation.

Unfortunately, even with copious amounts of grout introduced and flowed around behind such pipe piles, water leakage still occurs. In addition, the process of installing lagging plates remains relative tedious, expensive and consumes a large volume of materials to backfill the void behind the lagging plates.

Accordingly, it is an object of the present disclosure to provide an improved pile, method and system which addresses or at least partially ameliorates at least some of the above disadvantages or at least provides the public with an alternative choice. SUMMARY OF THE DISCLOSURE

Features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the herein disclosed principles. The features and advantages of the disclosure can be realized and obtained by means of the instruments and combinations of the appended claims.

In accordance with a first aspect of the present disclosure, there is provided a pipe pile comprising an elongate pipe body having at least a first engagement element and second engagement element extending longitudinally along the external periphery thereof; the first engagement element being configured to slidably receive in a cavity defined therein at least part of a second engagement element of an adjacent pipe pile for interengagement therewith; the second engagement element being configured to be at least partially slidably received in a cavity of a first engagement element of another adjacent pile pipe for interengagement therewith; wherein at least one of the first engagement element and the second engagement member have an expansible member affixed to at least one face disposed within said cavity before interengagement between the elongate pipe pile and the or each adjacent pipe piles.

Advantageously, the expansible member is a hydrophilic strip extending along the first and/or second engagement element which swells to occupy at least a portion of the cavity upon contacting water so as to prevent egress of water therethrough. The expansible member may be a polyurethane hydrophilic sealant which has an expanded volume which is between 2-3 times an initial volume; wherein said expansion is initiated by contact with water.

The expansible member may be affixed to a face of the second engagement element.

The pile may further include a grout pipe affixed to and extending along one side of the first engagement element, said grout pipe including one or more apertures defined therein. One or more of the apertures of the grout pipe may be oriented to direct grout proximate to the interengagement between the first engagement element and the second engagement element of the adjacent pipe pile.

The first engagement element may comprise a channel configured to receive a portion of the second engagement element via an open slot into the cavity.

Advantageously, the second engagement element has a substantially T-shaped cross section.

Preferably the first interlocking element is a C-shaped channel; wherein the C-shaped channel comprises two flanges and a web with the outermost edge of each flange being provided with an integral inwardly turned lip to form a longitudinally extending cavity between a web facing surface of lip and the web; and wherein a bottom surface opposite the cavity is attached to each pipe pile.

In a further aspect there is provided a pipe pile system comprising at least first and second adjacent pipe piles, each pipe pile having at least a first and second engagement element extending along an external periphery thereof; wherein said at least first and second pipe piles are interengaged with each other via a first engagement element comprising a cavity dimensioned to receive at least a portion of the second engagement element of an adjacent pipe pile; wherein at least one face of the cavity of the first engagement element and/or one face of the second engagement element of the cavity comprises an expansible strip extending substantially therealong with said expansible strip being affixed thereto before interengagement.

Preferably the expansible strip is a hydrophilic strip which swells to occupy at least a portion of the cavity upon contacting water so as to prevent egress of water therethrough.

The expansible strip may comprise polyurethane hydrophilic sealant which has an expanded volume which is between 2-3 times an initial volume; wherein said expansion is initiated by contact with water.

Advantageously, each of the pile piles further includes a grout pipe affixed to and extending along one side of the first engagement element, said grout pipe including one or more apertures defined therein.

The one or more apertures of the grout pipe may be arranged in a first column aligned to direct grout proximate to the interengagement between the first engagement element and the second engagement element of the adjacent pipe pile and one or more columns oriented facing towards the gap outside the first pipe pile during drilling of the pipe.

The one or more apertures may be arranged in three columns, with the first column aligned to direct grout proximate to the interengagement between the first engagement element and the second engagement element of the adjacent pipe pile; and the second and third columns of apertures in a column disposed at approximately 90 and 180 degrees therefrom.

The first engagement element may comprise a channel configured to receive a portion of the second engagement element via an open slot into the cavity.

The second engagement element may have a substantially T-shaped cross section.

The first interlocking element may be a C-shaped channel; wherein the C-shaped channel comprises two flanges and a web with the outermost edge of each flange being provided with an integral inwardly turned lip to form a longitudinally extending cavity between a web facing surface of lip and the web; and wherein a bottom surface opposite the cavity is attached to each pipe pile.

The pipe pile system may further include at least third and fourth pipe piles wherein each of the first, second, third and fourth pipe piles are engaged with and to at least one other pipe pile by respective first and second engagement elements extending along an external periphery thereof.

In a further aspect there is provided a method of constructing a pipe pile wall in a subsurface comprising: driving a first pipe pile into the subsurface, the first pipe pile having at least a first and second engagement element extending along an external periphery thereof; driving a second pipe pile having at least a first and second engagement element extending along an external periphery thereof into the subsurface adjacent to and in interengagement with the first pipe pile; wherein said interengagement is by receiving at least a portion of the second engagement element of the adjacent pipe pile in a cavity of a first engagement element of either the first pile or the second pile; wherein at least one of said at least first or second engagement elements of the first pipe pile or second pipe pile includes at least one or more expansible strip extending substantially therealong affixed thereto before interengagement with the adjacent pipe pile. Advantageously, the method may further comprise flowing cementitious grout into the subsurface proximate the interengagment region of the first and second pipe piles via apertures of a grout pipe affixed to and extending along either the first pipe pile or second pipe pile.

Optionally, the method may further comprise allowing expansion of the expansible strip in the cavity upon the ingress of water therein.

In yet a further aspect of the present disclosure there is provided a method of manufacturing interengagable pipe piles; the method comprising: affixing at least a first engagement element and a second engagement element along the external periphery of an elongate body of a first pipe pile; wherein the first engagement element is configured to slidably receive in a cavity defined therein a second engagement element of an adjacent pipe pile for interengagement therewith; including an expansible member on at least one face which will be disposed within said cavity.

The method of manufacturing interengageable pipe piles may further comprise affixing a grout pipe to extend along the elongate pipe body proximate the first engagement element.

Advantageously the first engagement element, second engagement element and grout pipe are affixed to the pipe pile by welding.

Optionally a longitudinally extending recess is defined in a projecting member of the second engagement element for receiving the expansible member therein.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended Figures. Understanding that these Figures depict only exemplary embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying Figures.

Preferred embodiments of the present disclosure will be explained in further detail below by way of examples and with reference to the accompanying Figures, in which:- FIG 1A depicts a single exemplary pipe pile in accordance with an embodiment of the present disclosure.

FIG 1 B depicts two exemplary pipe piles in an interengaged relationship.

FIG 1 C depicts a plurality of interengaged adjacent pipe piles forming a portion of a pipe pile wall.

FIG 2A depicts an exemplary first engagement member and second engagement member in an engaged relationship, in which the adjacent pipe piles have been removed for clarity.

FIG 2B depicts an exemplary first engagement member and second engagement member in an engaged relationship, in which the adjacent pipe piles have been removed for clarity, in which an adjoining grout pipe is included.

FIG 3A depicts an exemplary first engagement member.

FIG 3B depicts an exemplary second engagement member.

FIG 4 depicts an exemplary flow chart for making a pipe pile according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the disclosure.

The disclosed technology provides an improved pipe pile, system, manufacturing method and installation method using pre-fabricated pipe piles, which have enhanced waterproofing. In addition, in embodiments where a grout pipe is affixed to the pipe pile a reduced amount of grout is directed to the area in which it is most needed; at the same time avoiding the inconvenience of requiring a separate grout pipe hole being drilled.

Referring to Figs 1A-1 C, there is depicted a first pipe pile 10 having an elongate main body 12, to which a first engagement member 20 and second engagement member 30 is affixed. Advantageously, the first and second engagement members are made from steel and are of sufficient strength and stiffness to avoid being damage during installation. It would be appreciated that the present disclosure would not be limited to the shape or dimensions as described or depicted; and further and alternative cross sections and dimensions could be used.

As depicted, a strip of expansible material 32 extends along a face of the second engagement member 30. It would be appreciated that this expansible material may also extend along one or more faces of the first engagement member 20 in an alternative arrangement.

Also depicted is a grout pipe 40 disposed proximate to the first engagement member 20 and affixed so as to extend along the main body 12 of the elongate grout pipe. Advantageously, these engagement members 20, 30 may be also known as interlocks and may be affixed to the metal pipe pile by welding or similar. Similarly, the grout pipe 40 may be affixed to the metal pipe pile by welding or similar.

A second pipe pile 50 is depicted in Fig 1 B interengaged with the first pipe pile 10, via an engagement mediated by interaction between the first engagement member 20 of the first pipe pile 10 with the second engagement member of the second pipe pile 50 as described herein. A second engagement member 30 of the first pipe pile and a first engagement member 20 are depicted extending from opposite sides of the first pipe pile 10 and second pipe pile 50 respectively on either side of a diameter of the respective pipe piles. Other arrangements in which the engagement elements are not attached exactly opposite each other could also be envisaged, especially for forming the barrier wall into different shapes for particular applications.

The side marked “A” is the side in which the rock or soil strata is located; and in which the grout or other sealing cement is provided. The side marked “B” is the side on which further excavation may take place, and from which it is desirable to exclude water.

As depicted in Fig 1 C, a pipe pile wall 60 can be formed by the engagement of a plurality of pipe piles 10, 50, 52, 54, 56, 58 via the engagement of the first and second engagements as described herein.

It would be appreciated that the engagement between the first and second engagement elements of adjacent pipe piles may be by driving a first pipe pile into the subsurface of soil strata; and then sliding a second pipe pile into engagement with the first pipe pile before driving the second pipe pile into the soil and rock strata. There is included at least one or more expansible strip(s) extending along the pipe piles affixed thereto before interengagement with the adjacent pipe pile. Cementitious grout may be infiltrated into the subsurface proximate the interengagment region of the first and second pipe piles via apertures of a grout pipe affixed to and extending along either the first pipe pile or second pipe pile. Advantageously, if water does pass through the grout, it may be blocked by expanding the expansible strip in the cavity between the first and second engagement members.

This installation process can be understood further with reference to Fig 5.

Although six pipe piles are shown in an interengaged state in Fig 1C, it would be appreciated that more or less pipe piles could be interengaged to form a pipe pile wall without departing from the present disclosure.

Advantageously, this arrangement avoids the necessity to install lagging plates between spaced apart pipe piles; and supports the ground, especially in situations where the ground levels on one side are substantially different due to excavation. The holes required for the pipe piles of the present disclosure are also smaller in diameter, due to the relatively small projecting profile of the first and second engagement elements.

Advantageously, the external diameter of the grout pipe may be 48 mm, the internal diameter 42 mm and the holes/apertures 3-5 mm; although other dimensions could also be employed without departing from the scope of the present disclosure.

Referring now to Fig 2A and FIG 2B, there is depicted in more detailed an expanded view of the first engagement element 20 receiving and engaging a portion of the second engagement element 30 of the adjacent pipe pile.

It can be seen that the first engagement element 20 has a cavity 28 which receives the cross bar portion 33 of the second engagement element 30; and once inserted into the cavity 28 there is a limited amount of lateral movement of the engagement elements permitted. This in turn maintains the piles in a spaced apart but constrained lateral relationship, resisting lateral forces applied by the rock and soil strata.

It can be seen that the expansible member 32 is received in a slot 34 which is defined in the second engagement element 30. Preferably this slot 34 could be formed in the mould used for casting the engagement element or may be machined therein. The shape and depth of the slot 34 may be adjusted depending on the nature, type and amount of expansible material which will be affixed. Advantageously, the hydrophilic strip can be manually added in the manufacturing factory before delivery to construction site, or at the construction site before installation of the pipe, simply by attaching it to the slot 34 in the second engagement element 30. Preferably the hydrophilic strip comprises polyurethane, but other similar materials, that share the same performance characteristics of being easy to install; and which slowly expand to two to three times when contacting water could also be used. Advantageously, an exemplary product which could be used is a 1-part polyurethane sealant such as SikaSwell ®; which according to manufacturer data sheets may swell in an ideal concrete structure with a swelling pressure up to >10 bar.

Advantageously, the expansible member 32 may comprise polyurethane or similar, which is disposed in the slot 34 and expands upon contact with water. Therefore, it is good practice to keep the expansible member dry until installation if possible; even though the expansion process typically proceeds over several hours.

It would be appreciated that as the water enters the region between the interengaged first engagement element 20 and second engagement element 30, it contacts the expansible member 32 and causes it to swell. Preferably this expansible member 32 may swell 2-3 times its initial size so as to substantially fill much of any remaining space between the interengaged engagement members; thereby preventing the flow of water in between the pile members.

FIG 2B is the same as FIG 2A, except that as depicted in Fig 2B, a section of grout pipe 40 which is affixed to the first engagement element 20 is also shown with the holes 42a of the grout pipe directed toward the region of the interengaged first and second elements. Advantageously, plurality of holes 42 may be arranged in two or three columns, one column of holes facing towards the interengagement region between pipes 42a, and one column 42b or two columns 42b, 42c of holes facing towards the gap outside the first pipe pile during drilling of the pipe. Typically these grout holes may be approximately 5mm in diameter, although other measurements could be used without departing from the scope of the present disclosure.

The grout pipe 40 which is attached to the first engagement member is connected after installation to a grout pump and grout is infiltrated in the soil and rock strata around the region of the engagement members. This acts as an initial barrier to prevent the ingress of water near to the engaged piles; and further exclusion of water is provided by the expansible member.

It would be appreciated that the proximity of the grout pipe to the installed pipes; together with the arrangement of the apertures in the grout pipe can significantly reduce the amount of grout required to infiltrate the soil/rock strata. This arrangement avoids the necessity of having to drill separate grouting drill holes in a separate operation; and significantly reduces the amount of grout required.

Referring to the exemplary embodiment of the first engagement member 20 depicted in Fig 3A, it can be seen that the engagement member depicted is a C-shaped channel.

The C-shaped channel comprising two flanges 22a, 22b, joined by a web 24. The outermost edge of each flange being provided with an integral inwardly turned lip 26a, 26b to form a longitudinally extending cavity 28 between a web facing surface of the lips and the web. A bottom surface 29 opposite the cavity is attached to each pipe pile 10, preferably by welding.

Advantageously, the overall width of the C shaped channel may be 32.5 mm; with the thickness of the lip portions being approximately 8mm. The web portion 24 may have an exemplary thickness of 3mm; and a height of 80mm from the uppermost surface to the lowermost surface. The cavity entrance 28 between the inwardly turned lips 26a, 26b may be approximately 20mm. Other dimensions could also be employed without departing from the scope of the present disclosure.

Referring to Fig 3B, there is depicted a cross section of the second engagement element 30 as a substantially T-shaped rail. The base of the T-shaped member 31 welded or affixed to the pipe pile; while the cross bar portion 33 of the “T” shaped member includes a slot 34 into which the expansible member 32 is received.

Advantageously, the T shaped portion could have a length of 54mm; with the width of the base of the T-shaped member being approximately 14mm; and cross bar portion being 18mm on either side. The slot portion may have a width of approximately 16mm and a depth of approximately 5mm. Other dimensions could also be employed without departing from the scope of the present disclosure.

Advantageously, the interengagable pipe pile described herein may be manufactured by affixing by welding or similar of at least a first engagement element 20 and a second engagement element 30 along the external periphery of an elongate body of a pipe pile in the steps outlined in Fig 4.

As depicted, in step 72 these engagement elements comprise C-shaped channels and T- shaped rails which are welded to the pipe pile in a factory, remote from the construction site. Preferably the engagement elements 20 and 30 may be dimensioned and configured such that the cavity in the C-shaped channel receives a T-shaped rail of an adjacent pipe pile for interengagement with that adjacent pipe pile. It would be appreciated that in order for accurate interengagement between the T-shaped rail and C shaped channel, accuracy of alignment, dimension, shape and weld adequacy in the attachment to the pipe pile are all important. Preferably, these factors may be ensured in a factory remote from the construction site with appropriate supervision.

A grout pipe extending along the elongate pipe body proximate the first engagement element may also be advantageously affixed to the pipe pile prior to the inclusion of the expansible member typically, by welding in step 74 at the same or alternate factory premises remote from the construction site.

Typically a custom-made steel ring is welded to the bottom of the pipe piles in step 76, with a slightly smaller diameter than the pipe pile itself; so as to block the concentric drilling bit once the drill bit is below the pipe pile bottom. This ensures the drilling bit pushes the pipe pile down during drilling.

An expansible member may then be applied to a recess or slot or similar which is formed during casting or afterwards along at least one face which will be disposed within said cavity in step 78. It would be appreciated that the expansible member could be formed inside the C-shaped channel or on the T-shaped rail as depicted without departing from the scope of the present disclosure. Multiple expansible members on various faces could be included if required. The expansible member could be affixed on site or offsite at another factory.

Alternatively, the grout pipe may be added after the inclusion of the expansible member without departing from the scope of the present disclosure. Preferably the first engagement element, second engagement element and grout pipe are affixed to the pipe piles by welding.

Typically, once finished, the pipe piles may delivered to the construction site in step 80; and installed according to the following steps. A person skilled in the art would appreciate that such installation steps are exemplary and other steps could be used as appropriate with the pipe piles of the present disclosure without departing from the scope thereof.

When fabricated interlocked pipe piles are delivered to construction site, installation into the ground may be carried out according to the following steps: a) A hydrophilic strip is affixed in the T-shape engagement member of the pipe piles; either in the factory or at the construction site before use. b) A concentric drilling bit is inserted through the 1 ^st pipe pile until it is blocked by the 1 ^st steel ring at the base of pipe pile; c) A 2 ^nd custom-made steel ring is installed at bottom of pipe pile, and rotated clockwise to lock with the concentric drilling bit. The 2 ^nd steel ring is slightly larger than the pipe pile, with its diameter up to approximately the external edge of the C-shape interlock but slightly smaller than the T-shape interlock; d) Drilling is commenced, with the concentric drill bit being rotated anti-clockwise, with the

2 ^nd steel ring driven by the drill bit to rotate; e) The pipe pile is drilled to the required level to complete the drilling process. f) Drill bit is disengaged from installed pipe pile by rotating drill bit clockwise to disengage from 2 ^nd steel ring. g) Drill bit is extracted from the installed pipe pile, leaving the 2 ^nd steel ring on the end of the installed pipe pile. h) Steps b) and c) are repeated for each subsequent pipe pile; with the position of the subsequent pipe piles fixed so that the T-shaped engagement member of the latter pipe piles is received inside the adjacent C-shape engagement member of the earlier installed pipe pile. i) Steps d) to g) to install further pipe piles which are interengaged with earlier installed pipe piles so as to form a pipe pile wall at the desired location with the desired dimensions.

The pipe piles, pipe pile system and method of installation provide an efficient and waterproof solution to situations especially where the ground levels are of different heights. The expansible member seals off the joins between adjacent pipe piles, and substantially prevents the passage of water. The grout pipe avoids having to drill additional separate holes, and by directing grout to the region of soil and rock strata which is proximate the join between adjacent piles, minimises the grout required.

The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the disclosure as defined in the appended claims.

For clarity of explanation, in some instances the present technology may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines. Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims.