[0001] The invention relates to apparatuses and methods for repairing conduits, tunnels, culverts, and other like structures that have been damaged, weakened, or that have begun leaking, such as leaking water or other liquid or effluent. The invention more particularly relates to such apparatuses and methods for repairing such aforementioned structures that are located underground, without necessitating excavation of the surrounding terrain. The structures to be repaired can have a variety of cross sections, including round or non-round. The invention is particularly suitable for structures having an arch shape.

Background

[0002] Conduits, tunnels, and culverts can become damaged or weakened for various reasons, which require periodic repair or rehabilitation. For example, railways are built to follow horizontal contours of the landscape. Crossing moderately deep ravines, earthen dams have been built to maintain the track horizontal. These dams intersect natural waterways requiring culverts to allow the streams to pass. Many railways were built more than a century ago and culverts have been subjected to heavy vibrating loads. Furthermore, reinforced concrete walls of these culverts have undergone considerable water erosion rendering them structurally weakened and often unsafe.

[0003] U.S. Patent RE30,929 (Maimets) discloses a collapsible liner, in the form of a number of arcuate hinged segments that form a collapsed closed loop that is transported into the tunnel or conduit and, when positioned at the site of the repair, the collapsed closed loop is expanded by one or more inflatable air bags until it achieves its final erect installed closed-loop form. In the final form, an annular gap between the liner and the host pipe for receiving grout. With reference to Fig. 4 of US '929, the closed-loop form of the installed liner is locked in place as the pair of hinged-together liner segments 24-2 and 24-3 and the pair of hinged-together liner segments 24-6 and 24-7 are expanded outwardly toward the inner wall of the host pipe being repaired, as the air bags are inflated and the liner is moved to its final stable form. In this way, either or both of the pair of hinged liner segments, forming an overcenter mechanism, can be regarded as a liner locking device. The liner is sized so that, in its final installed form, an adequate space between the liner and the host pipe is provided for grout.

[0004] U.S. Patent Application Publication 2014/0007968 (Maimets) discloses another multi-segment liner apparatus and method that includes embodiments suitable for the repair of conduits and other like structures. In the first two embodiments the liner, which is also referred to as a repair sleeve or core, is used for repairing a host pipe having what is referred to as a horseshoe cross section. The liner, or sleeve, includes a pair of hinged crown segments, or flaps, in the area of the top arch region, an invert segment at the bottom of the host pipe, and a pair of oppositely opposed lateral segments, the bottoms of the latter segments to be positioned in respective ones of upwardly facing grooves in the invert segments.

[0005] In the pre-installation position of the first embodiment shown in Fig. 1 of US '968, the pair of hinged crown segments are positioned against the host pipe and either or both of the lateral segments can be considered as the liner locking device, as each is forced laterally to be fitted within its respective groove as the liner is moved to its final stable form.

[0006] In the pre-installation position of the second embodiment shown in Fig. 3 of US '968, the pair of lateral segments are positioned proximate the inner sides of the host pipe, fitted in their respective grooves, and the two hinged crown segments can be regarded as the liner locking device, similar to the liner of US '929. That is, in the arch area of US '968, to move the liner to its final stable form, the hinged crown segments are forced outwardly toward the inner surface of the host pipe.

[0007] As mentioned in claims 2 and 6 of US '968, resilient rings are placed around the outer surface of the sleeve, where they are compressed between the sleeve and the host pipe and where they also provide a gap between the sleeve and the host pipe to receive grout.

[0008] Despite the foregoing examples of repair methods and apparatuses, as well as others that are known in the field, a need remains for improvement and simplification for reducing installation costs and downtime, while maintaining or increasing the strength and durability of the repair.

Summary

[0009] The invention is directed to apparatuses and methods for internal repair of conduits, tunnels, culverts, and other like structures, generally referred to herein as a conduit or a host pipe, for convenience. The apparatus includes a repair sleeve configured to be moved from a pre-installed configuration to a stable installed configuration, the repair sleeve forming a closed circumferential loop in the installed configuration, which can line a bottom, a top, and a pair of opposite lateral portions of the host pipe.

[0010] The repair sleeve includes a plurality of segments configured to line the inner peripheral and lengthwise surfaces of the host pipe, wherein, for an exemplary embodiment, the host pipe comprises a bottom region, a top region, and right and left lateral regions, and wherein the plurality of segments of the sleeve include at least a bottom segment to be positioned above the bottom region of the host pipe in the installed configuration, a right lateral segment to extend upwardly from the bottom region of the host pipe along the right lateral region of the host pipe in the installed configuration, and a left lateral segment to extend upwardly from the bottom region of the host pipe along the left lateral region of the host pipe in the installed configuration.

[0011] The repair sleeve also includes a locking mechanism configured to lock the repair sleeve in the stable installed configuration while allowing a gap between an outer surface of the repair sleeve and an inner surface of the host pipe. In the installed configuration of the sleeve, the locking mechanism is positioned within the annular gap between the sleeve and the host pipe.

[0012] In particular embodiments of the invention, the locking mechanism comprises at least two or more wedges that are spaced apart around a periphery of the sleeve in the gap. Once installed, the wedges add compressive forces against the parts of the sleeve as a grout or other binding agent, cementitious or chemical, for example, cures in the gap between the sleeve and the host pipe.

[0013] A plurality of such repair liners can be successively positioned and installed lengthwise along the host pipe in an abutting relationship, for example, the number depending upon the size of the repair, although the liners can be joined together by any convenient means, such as with interlocking structures or with an elastic band surrounding the end regions of adjacent liners. The aforementioned wedges, constituting a locking device for each of the liners, secure the liners in place until the binding agent has cured, whereby the binding agent creates the composite structure consisting of the liner, the binding agent, and the existing deteriorated walls of the host pipe.

[0014] The liner material can be chosen to enhance the hydraulic properties of the relined conduit by being made of rigid PVC, or other water rejecting material.

[0015] The invention also includes a method of installation of a repair sleeve of the invention within a conduit or host pipe. Brief Description of the Drawings

[0016] Characteristics and advantages of the invention will be better understood from the following description and the annexed drawings illustrating, by way of non- limiting embodiments, how the invention can be carried out, and in which:

• FIG. 1 is a transverse cross-sectional view of a conduit in need of repair, showing bottom components of an apparatus of a first embodiment of the invention with the repair sleeve in a pre-installation configuration, including a bottom segment of a repair sleeve according to the invention, which is to be completed and installed within the conduit;

• FIG. 2 is a view similar to that of FIG. 1 with a left lateral segment having an end positioned within a groove of the bottom segment, with an arrow showing that the left lateral segment is to be tilted about its end toward the left lateral surface of the conduit;

• FIG. 3 is a view similar to that of FIG. 2 with a right lateral segment having an end positioned within another groove of the bottom segment, with an arrow showing that the right lateral segment is to be tilted about its end toward the right lateral surface of the conduit;

• FIG. 4 is a view similar to that of FIG. 3 with both the left and right lateral segments of the repair sleeve positioned proximate the left and right lateral surfaces of the conduit, the repair sleeve forming a closed circumferential loop while being in an intermediate configuration, without grout yet injected between the repair sleeve and the conduit;

• FIG. 5 shows the repair sleeve in the installed configuration, and with grout having been injected in a gap surrounding the repair sleeve, the gap having a width defined by the inner surfaces of the conduit, with top and bottom wedges creating the gap;

• FIG. 6 is longitudinal cross-sectional view taken along the lines VI-VI of FIG. 5; and • FIGS. 7-12, which correspond respectively to FIGS. 1-6, show a second embodiment of an apparatus of the invention in which a metallic mesh has been installed against the walls of the conduit prior to the assembly of the sleeve segments shown in FIGS. 1-6.

Detailed Description

[0017] In the following description, terms denoting direction or position, such as "top", "bottom", "longitudinal", "transverse", "vertical", "horizontal", "left" and "right", should be considered relative terms used for convenience in the following description in relation to exemplary directions and positions occupied by the various components of apparatuses shown in the various drawing figures, as well as the conduit or host pipe that is to be repaired by such apparatuses and methods. For example, a conduit or host pipe to be repaired according to apparatus and methods of the invention can extend horizontally, vertically, near vertical, along an incline, and otherwise. In addition, terms such as "annular" and "circumferential" are used for convenience, such as in connection with a repair sleeve and a gap between a repair sleeve and a host pipe, but the terms are not to limit such repair sleeve and host pipe or portions thereof are circular or partially circular in cross section, for example.

[0018] FIGS. 1-6 illustrate a non-limiting first embodiment of an apparatus within the scope of the invention. More particularly, the drawing figures show an exemplary step-by-step method of assembling various segments of a repair sleeve of the apparatus of the invention within a damaged, weakened, and/or leaking conduit 6, herein also referred to as a the pipe. The host pipe can have any height, but the invention is particularly useful for pipes having heights that allow access to personnel for installing the various components of the apparatus of the invention to line the host pipe. For example, such heights can be within a range of at least 5-12 feet. Further, although the bottom of the host pipe 6 is shown to have an arcuate upwardly concave shape, the invention can be practiced with flat or other bottom shapes. [0019] FIGS. 5 and 6 illustrate the repair sleeve in an installed configuration, in which a grout 10 has been injected through grout ports 9 into a gap between the host pipe and the outer surfaces of the segments 3, 7, and 8 of the repair sleeve, of which the segments can also be referred to as flaps. That is, in the installed configuration of the illustrated first embodiment, the repair sleeve includes a bottom segment 3, a left segment 7, and a right segment 8. FIGS. 1-4 illustrate, in a step-by-step manner, a successive positioning of the segments from a pre-installation configuration to an intermediate configuration (that is, with grout not yet injected into the gap), the latter showing the segments forming a closed circumferential loop.

[0020] The longitudinal cross-sectional view of FIG. 6 shows an exemplary relative length of the repair sleeve. The length can be of any conventional or convenient dimension and can be chosen for ease of handling by the installation crew and, for example, the weight of the materials used for the segments. For example, if the height of the completed repair sleeve were to be five feet, the length of the repair sleeve from upstream end to downstream end could be two, four, or six feet. But any convenient dimensions are possible. Depending upon the length of the damaged, weakened, or leaking region of the host pipe, two or more successive repair sleeves can be installed.

[0021] The material of the sleeve, that is, the material used for the sleeve segments, can be polyvinyl chloride (PVC), although the choice of material is determined by the chemical regime in the host pipe. Alternatively, corrugated or galvanized metal, for example, could be used. The thickness of the sleeve segments can be any dimension taking into account the resulting weight of the segments as they are transported and installed. As an example for PVC, the thickness can be within a range of 0.625 inches to 1.50 inches, although other thicknesses are within the scope of the invention. The choice of thickness of the sleeve segments is determined by the dimensions and external loads applied to the host pipe. [0022] In FIG. 1, the bottom segment 3 has been positioned at the bottom region of the host pipe 6, but is spaced from the host pipe by means of at least one wedge 4. In the final installed configuration shown in FIGS. 5 and 6, at least one additional wedge 4 is positioned above the respective abutting edges of the right and left segments 7 and 8, the two wedges thereby defining a gap surrounding the repair sleeve, the gap additionally defined by the inner surfaces of the host pipe. The wedges can be made of wood or plastic, for example, or other relatively hard or rigid material that can maintain a spacing between the repair sleeve and the host pipe and maintain the spacing during the injection and curing of the binding material. In an exemplary embodiment, the wedges can have a width that maintains a two-inch gap, although the width of the gap can be of any suitable size that provides sufficient rigidity for the final composite structure once the grout or other binding agent is cured within the gap. For example, and non-limiting to the invention, the gap could have a width within the range of 1-5 inches.

[0023] In addition to the bottom segment 3 and wedge 4, as shown in FIG. 1, the bottom components include elastomeric, or otherwise resilient, pads 1 and 2 beneath respective ones of the left and right end regions of the bottom segment 3. More particularly, in the illustrated embodiment, each of the pads is located beneath an upwardly facing groove 5 that receives an end, that is, a bottom edge, of a lateral segment 7 or 8, as explained below. Although the pads are shown to have a circular cross section, other shapes are possible, such as rectangular or otherwise. Also, the pads 1, 2 can have a length the same as the length of the wedges 4 (see FIG. 6, for example), although other lengths are possible so as to perform their function of supporting the lateral segments and providing a resilient force against the ends of the lateral segments.

[0024] In FIG. 2, the left lateral segment 7 of the repair sleeve is manually installed, although possibly with the assistance of a mechanical or hydraulic device, by having an end positioned, and thereby locked, within the groove 5 of the bottom segment, and then tilting the segment 7 (indicated by the arrow in FIG. 2) hinge-like toward the left lateral surface of the host pipe 1. The segment 7 can be temporarily held or braced in place manually or with the use of a mechanical or hydraulic device.

[0025] Next in this step-by-step installation of the repair sleeve, after the left lateral segment 7 has been placed in position proximate the left lateral surface of the host pipe, as shown in FIG. 3, the right lateral segment 8 of the repair sleeve is installed by positioning, and thereby locking, its bottom end within the groove 5 on the right of the bottom segment 3, and then tilting the right lateral segment 8 (indicated by the arrow in FIG. 3) hinge-like toward the right lateral surface of the host pipe 1. Of course, the right lateral segment 8 can be installed before the left lateral segment, or both lateral segments can be installed at the same time. For the latter, each of the lateral segments can be raised/tilted by a respective worker either manually or with the assistance of a mechanical or hydraulic device. In any event, when both of the lateral edges are raised in place as shown in FIG. 4, their respective upper ends, or lengthwise-extending edges, are in abutment. The ends, or edges, can be flat or the two ends or edges of the lateral segments can have a shiplap engagement or other engagement. Although grooves 5 are illustrated in the exemplary embodiment the ends of the lateral segments 7, 8 could alternatively be locked in place, such as to prevent sliding of the bottoms of the sleeve segments, by means of fasteners or other securing devices.

[0026] After the upper ends of the lateral segments 7, 8 come into abutment as shown in FIG. 4, a wedge 4 is forced into place above the abutting ends as shown in FIGS. 5 and 6, such as by hammering. The closed loop of the segments has a sufficient resiliency to accept the wedge to firm up its rigidity in the installed configuration prior to receiving the grout in the gap. That is, as the upper wedge 4 is so installed, the lateral segments 7 and 8 are compressed downwardly thereby compressing the resilient pads 1 and 2, and thereby creating a locking force to fix the repair sleeve in a closed loop configuration, that is, in the installed configuration of the repair sleeve, as shown in FIGS. 5 and 6. [0027] After the wedges 4 are installed, a grout or other binding agent 10, cementitious or chemical, for example, is injected through the ports 9 into the gap between the repair sleeve and the host pipe, as shown in FIGS. 5 and 6, where it cures in place and thereby increases the rigidity and structural strength of the repair sleeve, or that of any lengthwise succession of repair sleeves that might have been created, as mentioned above, depending upon the size of the repair.

[0028] When the grout 10 cures, the resiliency of the pads 1 and 2 is eliminated inasmuch as the pads are subsumed by the rigid grout 10 within the gap.

[0029] Although each of the lateral segments 7, 8 are shown as one-piece segments, the invention encompasses a repair sleeve in which either or each of the lateral surfaces of the host pipe could be lined with a multi-link lateral segment. Such repair sleeve might be useful if the height of the host pipe might make the installation easier. Adjacent links of such multi-link segment can be joined by hinges, such as flexible hinges shown and described in the aforementioned US RE30929 (see hinges 28-1 to 28-8, for example), each of which can be an elastomer or metal strip glued or otherwise secured to the ends of adjacent links. The disclosure of US RE30929 is hereby incorporated by reference thereto in its entirety and particularly for this purpose. In such an embodiment, a wedge 4 would be installed along, and outwardly from, respective ones of the hinges within the grout gap.

[0030] FIGS. 7-12, which correspond respectively to FIGS. 1-6, show a second embodiment of an apparatus of the invention in which a reinforcing layer 11, such as a welded metallic mesh, is installed against the walls of the conduit prior to the assembly of the sleeve segments shown in FIGS. 1-6 to increase the strength of the repair sleeve. Other materials can also be used, as mentioned above with regard to the material of the sleeve segments.

[0031] In this embodiment, the reinforcing layer 11 is installed before the segments 3, 7, 8 are assembled, as is evident from FIGS. 7-9. After the reinforcing layer is installed, the same procedure is then applied for the construction and installation of the repair sleeve for the embodiment of FIGS. 7-12.

[0032] Alternative constructions and methods of installation are also possible without departing from the scope of the invention. That is, the invention is not limited to the particular embodiments described above, and includes all technical equivalents that fall within the scope of the claims that follow.

[0033] In addition, at least because the invention is disclosed herein in a manner that enables one to make and use it, by virtue of the disclosure of particular exemplary embodiments, such as for simplicity or efficiency, for example, the invention can be practiced in the absence of any additional element or structure that is not specifically disclosed herein. For example, with the locking device in the form of a plurality of wedges creating a gap between the repair sleeve and the host pipe, elastic rings or other structure, such as necessitated by the sleeve of US '968, are not needed to encircle the repair sleeve of the invention to create a gap for receiving grout between the repair sleeve and the host pipe.