Rehabilitation structure for existing drainage channels

Abstract

To provide the renovation structure of an existing culvert difficult to be set into design when renovating strength of the existing culvert, due to secular degradation.SOLUTION: The renovation structure of an existing culvert comprises a rehabilitation pipe 2 provided inside a box culvert being an existing culvert 1, an annular reinforcing member 3 arranged between the rehabilitation pipe 2 and the existing culvert 1, and filler 4 filled between the rehabilitation pipe 2 and the existing culvert 1 and solidified. Only the renovation structure has strength for supporting a load applied from surroundings of the existing culvert 1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rehabilitation structure for an existing channel, comprising a rehabilitation pipe provided inside the existing channel, an annular reinforcing member disposed between the rehabilitation pipe and the existing channel, and a filling material filled and solidified between the rehabilitation pipe and the existing channel.

Background Art

[0002] Conventionally, for example, channels (waterways) constructed of stone masonry, concrete, etc. have been used in urban areas for a long time. Some of these channels were originally open channels, and their upper parts have been covered to form culverts for use as roads, etc. due to urban development, etc. However, deterioration due to collapse, cracks, etc. of stone masonry and concrete has progressed, and the functions and strength as channels are no longer guaranteed.

[0003] As countermeasures against this, there are methods for renewing and rehabilitating existing culverts. The method of renewing an existing culvert has the drawback that it is necessary to remove the existing culvert once, which requires a huge amount of labor and cost, and also affects the lives of citizens due to large-scale traffic restrictions, etc. Therefore, there has been a demand for a method of rehabilitating an existing culvert in the state of a culvert without the above problems.

[0004] By the way, as a method of rehabilitating an existing channel, a method using a rehabilitation pipe made of a thermoplastic resin or a thermosetting resin has been proposed (see, for example, Patent Documents 1 and 2). According to the methods disclosed in Patent Documents 1 and 2, although the purpose of rehabilitating an existing culvert can be achieved to some extent, since a large improvement in the strength of the existing channel cannot be expected from the rehabilitation pipe itself, for example, even if an existing culvert whose strength has decreased and the strength to support the load applied from the surroundings is not guaranteed because the ground surface is used as a road, etc. is rehabilitated by these methods, it has been difficult to guarantee its strength.

[0005] Furthermore, when rehabilitating existing pipes, it is common practice to design the strength of the rehabilitation structure as an integrated unit of the existing pipe and the rehabilitated section. However, in the case of existing underground pipes that have deteriorated due to the collapse or cracking of stonework or concrete, it has been difficult to incorporate the strength of the existing underground pipe itself into the rehabilitation design. This is also true for existing pipelines made of concrete or steel pipes that have deteriorated over time, and in such cases, it has been difficult to incorporate the strength of the existing pipeline itself into the design for rehabilitation. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-294679 [Patent Document 2] Japanese Patent Publication No. 2012-219985 [Patent Document 3] Patent No. 5746443 [Patent Document 4] Japanese Patent Publication No. 2017-198305 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In view of the problems of conventional existing underground drainage systems and existing pipes, this invention addresses the difficulty of incorporating the inherent strength of existing underground drainage systems and existing pipes, which deteriorate over time, into the design when rehabilitating them (as specified herein). In this context, existing underground culverts and existing pipe culverts are collectively referred to as "existing culverts." The purpose is to provide a rehabilitation structure for these existing culverts. [Means for solving the problem]

[0008] To achieve the above objective, the rehabilitation structure for an existing channel of the present invention comprises a rehabilitation pipe provided inside the existing channel, an annular reinforcing member disposed between the rehabilitation pipe and the existing channel, and a filling material that is filled and solidified between the rehabilitation pipe and the existing channel. The rehabilitation structure is characterized by having sufficient strength to support the load applied from around the existing channel using only the rehabilitation structure itself.

[0009] In this case, the rehabilitation pipe may be provided with a surface material made of synthetic resin.

[0010] Furthermore, a connecting member can be provided on the annular reinforcing member, and a rehabilitation pipe can be provided on the connecting member.

[0011] Furthermore, the annular reinforcing member can be made of deformed reinforcing bars.

[0012] Alternatively, a rail member extending in the axial direction of the existing channel can be installed on the inner bottom side of the existing channel, and the annular reinforcing member can be placed on the rail member.

[0013] Furthermore, the annular reinforcing member may comprise an outer circumferential reinforcing member and an inner circumferential reinforcing member.

[0014] Furthermore, the center position of the outer peripheral reinforcing member can be positioned at least 23 mm from the inner surface of the existing channel and at a position on the outer circumference that is no more than half the thickness of the filling material, and the center position of the inner peripheral reinforcing member can be positioned at least 21 mm from the back surface of the rehabilitation pipe and at a position on the inner circumference that is no more than half the thickness of the filling material. [Effects of the Invention]

[0015] According to the existing channel rehabilitation structure of the present invention, existing channels, whose inherent strength due to aging deterioration is difficult to incorporate into the rehabilitation design, can be rehabilitated to a state in which strength capable of supporting loads from the surroundings is guaranteed. In other words, without considering the inherent strength of the existing channel itself, it is possible to rehabilitate it to a state in which strength capable of supporting loads from the surroundings is guaranteed, making it possible, for example, to safely use the ground surface as a road or the like. [Brief explanation of the drawing]

[0016] [Figure 1] Fig. 1 shows a first embodiment of the rehabilitation structure of an existing canal according to the present invention, where (a) is a cross-sectional view and (b) is an enlarged cross-sectional view of the surface layer of the rehabilitation pipe. [Figure 2] Fig. 2 is a longitudinal sectional view of a reinforcing member of the rehabilitation structure of the existing canal. [Figure 3] Fig. 3 is an explanatory diagram of strength design using the limit state design method for the case of a rehabilitation structure in which an existing pipe canal and a rehabilitation part are integrated (general rehabilitation structure of an existing canal). [Figure 4] Fig. 4 is an explanatory diagram of strength design using the limit state design method for the case of a rehabilitation structure composed of only the rehabilitation part (rehabilitation structure of the existing canal according to the present invention). <00s0089> [Figure 5] Fig. 5 is a cross-sectional view showing a first modification of the first embodiment of the rehabilitation structure of the existing canal according to the present invention. [Figure 6] Fig. 6 is a cross-sectional view showing a second modification of the first embodiment of the rehabilitation structure of the existing canal according to the present invention. [Figure 7] Fig. 7 shows a rail member of the rehabilitation structure of the existing canal, where (a) is a plan view, (b) is a partially enlarged front view, and (c) is a partially enlarged side view. [Figure 8] Fig. 8 is a cross-sectional view showing a second embodiment of the rehabilitation structure of the existing canal. [Figure 9] Fig. 9 shows examples of the rehabilitation structure of a conventional existing pipe canal, where (a) is an explanatory diagram showing the rehabilitation structure of an existing pipe canal with a circular cross-section, and (b) is an explanatory diagram showing the rehabilitation structure of an existing pipe canal with a rectangular cross-section.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of the rehabilitation structure of an existing canal according to the present invention will be described based on the drawings.

[0018] Figs. 1 to 2 show a first embodiment of the rehabilitation structure of an existing canal according to the present invention. This rehabilitation structure of the existing canal includes a rehabilitation pipe 2 provided inside the existing canal 1, an annular reinforcing member 3 disposed between the rehabilitation pipe 2 and the existing canal 1, and a filler 4 filled and solidified between the rehabilitation pipe 2 and the existing canal. It is a rehabilitation structure of an existing canal, and it is configured to have a strength to support the load applied from around the existing canal only by this rehabilitation structure. Here, the portion of the existing channel 1 consisting of the rehabilitation pipe 2, reinforcing member 3, and filling material 4 is referred to as the rehabilitation section R.

[0019] By the way, the existing culvert 1 targeted for rehabilitation in this embodiment is a box culvert with a rectangular cross-section, but it is not limited to this. In addition to reinforced concrete pipes (Hume pipes) with a circular cross-section, existing culverts with walls made of stone masonry are also targeted for rehabilitation.

[0020] For the rehabilitation pipe 2, a wide range of known rehabilitation pipes used to rehabilitate aging sewer pipes and other existing pipes can be used. However, in this embodiment, the rehabilitation pipe shown in Figure 9 (FFT Method Association "String Method" (registered trademark)) (see Patent Documents 3 and 4) is used.

[0021] The rehabilitation pipe 2 is equipped with a strip-shaped inner material 21 made of synthetic resin such as high-density polyethylene, and a fastener 22 made of synthetic resin such as high-density polyethylene thermoplastic elastomer that connects adjacent inner materials 21 and covers the gap between them.

[0022] The inner material 21 of the rehabilitation pipe 2 is installed on a connecting member 23 located on an annular reinforcing member 3 positioned along the inner surface of the existing channel 1, and on a connecting member 23 located on an annular reinforcing member 3 adjacent to the rehabilitation pipe 2 in the direction of the pipe axis, via a spacer that defines the spacing between the connecting member 23 and the connecting member 23.

[0023] The annular reinforcing member 3 comprises an annular outer reinforcing member 31 made of deformed reinforcing bars installed at intervals in the axial direction of the rehabilitation pipe 2, an annular inner reinforcing member 32 made of deformed reinforcing bars installed at intervals inside the outer reinforcing member 31, and positioning bars 33 for the outer reinforcing member 31 and the inner reinforcing member 32. Furthermore, the axial reinforcement bars 34 are arranged to span across adjacent annular outer reinforcing members 31 and inner reinforcing members 32 in the direction of the pipe axis.

[0024] A high-flow, high-strength mortar can be suitably used as the filler material 4.

[0025] The size (diameter) and arrangement of the outer peripheral reinforcing member 31, the inner peripheral reinforcing member 32, the positioning bars 33 and the shaft bars 34, as well as the thickness of the filling material 4, are designed so that the rehabilitation structure alone has the strength to support the loads applied from around the existing channel. This makes it possible to rehabilitate an existing channel 1, which has become difficult to incorporate its own strength due to aging into the rehabilitation design, to a state in which the strength to support loads applied from around is guaranteed. Specifically, the outer periphery reinforcing member 31 and the inner periphery reinforcing member 32 shall use deformed reinforcing bars of D13 (designation according to JIS G 3112; the same applies hereinafter) (D6 to D22). Then, taking into account the cover thickness due to the filler material 4, the size (diameter) of the deformed reinforcing bar to be used should be adjusted accordingly. In addition, the center position of the outer peripheral reinforcing member 31 is preferably located at a position on the outer periphery that is 36.5 mm (in the case of D13) (33 mm (in the case of D6) to 41 mm (in the case of D22)) or more from the inner surface of the existing channel 1, and at a position that is no more than half the thickness of the filler material 4. Here, the value of the center position of the outer reinforcing member 31 that defines the cover thickness by the filler material 4 can be set to a value smaller than the above value, as long as at least 23 mm is secured. On the other hand, the center position of the inner circumferential reinforcing member 32, which is covered with a strip-shaped inner surface material 21 made of synthetic resin with a thickness of several mm in addition to the filler material 4, is positioned at least 24.5 mm (in the case of D13) (21 mm (in the case of D6) to 26 mm (in the case of D22)) from the back surface of the rehabilitation pipe 2 (the surface to which the cast filler material 4 comes into contact), and at an inner circumferential position that is no more than half the thickness of the filler material 4. This ensures sufficient cover thickness and improves durability.

[0026] The outer circumferential reinforcing member 31, the inner circumferential reinforcing member 32, the positioning bars 33, and the axial bars 34 shall be arranged in accordance with the strength design. Specifically, the pitch P of the reinforcement bars in the outer periphery reinforcing member 31 and the inner periphery reinforcing member 32 can be set, for example, as shown in Table 1. Here, the reinforcement pitch P of the outer periphery reinforcing member 31 and the inner periphery reinforcing member 32 is the same or one is an integer multiple of the other, and the reinforcement is arranged so that the outer periphery reinforcing member 31 and the inner periphery reinforcing member 32 overlap.

[0027] [Table 1]

[0028] Incidentally, when rehabilitating an existing channel, it is common practice to consider the existing channel 1 and the rehabilitated section R as an integrated rehabilitation structure and perform strength design accordingly, as shown in Figure 3. In this case, the strength design will be performed using a structural design method employing the limit state design method so that the existing reinforcing bars 1R of the existing channel 1 can withstand external tensile failure caused by loads applied from around the existing channel 1, and the inner circumferential reinforcing member 32 of the rehabilitated section R can withstand internal tensile failure.

[0029] On the other hand, in this embodiment, even when the existing channel 1 is rehabilitated in a similar manner, as shown in Figure 4, in order to ensure that the rehabilitated section R alone has the strength to support the load applied from around the existing channel 1, regardless of whether or not there is existing reinforcement 1R in the existing channel 1, the strength design is performed using a structural design method employing the limit state design method so that the outer peripheral reinforcing member 31 of the rehabilitated section R has sufficient strength against outer tensile failure caused by the load applied from around the existing channel 1, and the inner peripheral reinforcing member 32 of the rehabilitated section R has sufficient strength against inner tensile failure.

[0030] This makes it possible to rehabilitate an existing channel 1, whose inherent strength is difficult to incorporate into the design when rehabilitating it due to deterioration over time, to a state in which strength to support loads from the surroundings is guaranteed. In other words, it is possible to rehabilitate it to a state in which strength to support loads from the surroundings is guaranteed without considering the inherent strength of the existing channel 1 itself, making it possible to safely use the ground surface as a road, for example.

[0031] Here, a first modified example of the first embodiment of the rehabilitation structure for existing channels of the present invention shown in Figure 5 and a modified example shown in Figure 6 are presented. As shown in the second modified example, the rail members 51 and 52 shown in Figure 7 can be used to install the annular reinforcing member 3, which consists of an outer reinforcing member 31 and an inner reinforcing member 32, in predetermined positions. In the first modified example of the first embodiment shown in Figure 5, the rail member 52 is positioned between the outer peripheral reinforcing member 31 and the inner peripheral reinforcing member 32 on the inner bottom side of the existing channel 1. In the second modified example of the first embodiment shown in Figure 6, in addition to the rail member 52, the rail member 51 is positioned between the inner bottom of the existing channel 1 and the outer peripheral reinforcing member 31, both installed in the axial direction of the existing channel 1, with the outer peripheral reinforcing member 31 placed on the rail member 51 and the inner peripheral reinforcing member 32 placed on the rail member 52. As shown in Figure 7, rail members 51 and 52 are constructed by connecting multiple (three each in this embodiment) shaped steel (in this embodiment, channel steel is used, but I-beams and the like can also be used) in a grid-like manner with fixing members 53 arranged perpendicular to them. When channel steel is used for rail members 51 and 52, the width dimension of the lower flange should be larger than the width dimension of the upper flange (for example, upper flange width dimension: 30 mm, lower flange width dimension: 50 mm). Then, at the position of the upper flange, the rail members 51 and 52 adjacent to the existing channel 1 in the axial direction should be connected using a threaded member 55 via a connecting member 54, and a threaded member 56 for absorbing unevenness in the inner bottom of the existing channel 1 should be positioned on the lower flange in an easily accessible location. The height dimensions (web dimensions) of rail members 51 and 52 are set according to the design interval between the inner bottom of the existing channel 1 and the outer reinforcing member 31 in the case of rail member 51, and between the outer reinforcing member 31 and the inner reinforcing member 32 in the case of rail member 52 (in this embodiment, web dimensions: 60 to 110 mm). By using these rail members 51 and 52, the outer reinforcing member 31 and the inner reinforcing member 32 can be accurately and reliably supported and installed in their predetermined positions while absorbing the unevenness of the inner bottom of the existing channel 1. Furthermore, the other configurations and operations of this embodiment are the same as those of the existing channel rehabilitation structure in the first embodiment described above.

[0032] Furthermore, the second embodiment of the existing channel rehabilitation structure of the present invention shown in Figure 8 targets an existing channel 1 equipped with a side wall section 11 made of stone masonry for rehabilitation. Specifically, the existing channel 1 is constructed with stone masonry for the side walls 11, concrete for the bottom 12, and a concrete floor slab supported by PC girders for the top surface 13. This embodiment is for rehabilitating an existing channel 1 in which water infiltrates from the surrounding ground through a side wall 11 made of stone masonry. It comprises a rehabilitation pipe 2 that forms a water channel inside, an annular reinforcing member 3 placed between the rehabilitation pipe 2 and the existing channel 1, a filling material 4 that is filled and hardened between the rehabilitation pipe 2 and the existing channel 1, a planar member 6 provided at the boundary between the filling material 4 and the side wall 11 of the existing channel 1, and a water intake pipe 7 provided in the direction of the pipe axis of the rehabilitation pipe 2 at the boundary between the filling material 4 (or the planar member 6 if provided) and the existing channel 1, into which water that has infiltrated from the surrounding ground through the side wall 11 of the existing channel 1 is introduced.

[0033] In this embodiment, the planar member 6 guides and introduces water that has seeped in from the surrounding ground through the side wall portion 11 of the existing channel 1, which is made of stone masonry, into the water conduit 7, and also prevents the fluid-filled cast filling material 4 from leaking to the existing channel 1. Therefore, it is provided only at the boundary between the filling material 4 and the side wall portion 11 of the existing channel 1. However, depending on the structure of the existing channel 1, it may also be provided at the bottom portion 12 or the top portion 13.

[0034] The planar member 6 may include a waterproof sheet made of synthetic resin such as polyethylene or polyvinyl chloride (for example, "Binon" (registered trademark) manufactured by Takiron CI Corporation), which has the function to achieve the above objective, as well as an embossed drainage and protective mat (for example, "Geoflow" (registered trademark) manufactured by Takiron CI Civil Corporation), a planar drainage material (for example, "Grisheet" manufactured by Takiron CI Civil Corporation). A planar member with water-impermeable and water-permeable properties, such as (product name), can be used.

[0035] The water conduit 7 is intended to introduce water that has seeped in from the surrounding ground through the side wall 11 of the existing channel 1, and to drain the introduced water to the outside, for example, into a waterway formed inside the rehabilitation pipe 2 at an appropriate location. It is laid at the lowest position of the side wall 11 of the existing channel 1, which is made of stone masonry (or, if multiple are provided, at the lowest, upper, and intermediate positions of the side wall 11 of the existing channel 1), at a location that does not affect the strength of the rehabilitation pipe 2 and the water conduit 7 at the boundary between the filling material 4 (or the planar member 6 if one is provided) and the existing channel 1.

[0036] For the water conduit 7, perforated pipes or mesh pipes made of synthetic resin such as polyethylene (for example, Takiron CI Civil's "Super Pipe W-type" external pressure collection pipe and "Double Drain" underground drainage pipe) can be used, which have the function to achieve the above purpose.

[0037] According to this existing channel rehabilitation structure, a water conduit 7 is provided at the boundary between the filling material 4 (or the planar member 6 if one is provided) and the existing channel 1, in the direction of the pipe axis of the rehabilitation pipe 2. This conduit 7 introduces water that has seeped in from the surrounding ground through the side wall 11 of the existing channel 1. By discharging water that has seeped around the rehabilitation pipe 2 of the existing channel 1, where there are places where water seeps in from the surrounding ground through the wall made of stone masonry or concrete, via the water conduit 7, water that has seeped in around the rehabilitation pipe 2 does not accumulate, preventing the rehabilitation pipe 2 from floating due to buoyancy and preventing the surrounding ground from washing away and causing a sinkhole. Furthermore, since this rehabilitation structure for the existing channel can be constructed without excavating the existing channel 1, it reduces costs and shortens the construction period, while minimizing the impact on the surrounding area. Furthermore, the other configurations and operations of this embodiment are the same as those of the existing channel rehabilitation structure in the first embodiment described above.

[0038] The rehabilitation structure for existing drainage channels of the present invention has been described above based on its embodiments. However, the present invention is not limited to the configuration described in the above embodiments, and its configuration can be modified as appropriate without departing from the spirit of the invention. [Industrial applicability]

[0039] The rehabilitation structure for existing drainage channels of the present invention can provide a rehabilitation structure for existing drainage channels where it is difficult to incorporate the inherent strength due to aging into the design during rehabilitation. Therefore, it can be suitably used for the rehabilitation of existing underground drainage channels and existing piped channels where it is difficult to incorporate the inherent strength due to aging into the design during rehabilitation. [Explanation of symbols]

[0040] R Rehabilitation Department 1. Existing drainage channels (existing underground channels, existing pipe channels) 11 Side wall section 12 Bottom 13 Top section 2 Rehabilitation pipe 21. Inner material 22 zippers 23 Connecting member 3. Reinforcement members 31 Outer periphery reinforcing member 32 Inner Circumferential Reinforcement Member 33 Positioning muscles 34 Axial muscles 4 Filling material 51 Rail Member 52 Rail components 6-sided member 7. Water conduit

Claims

1. A method for designing the strength of a rehabilitation structure for an existing channel, comprising: a rehabilitation pipe installed inside the existing channel; an annular reinforcing member consisting of an outer reinforcing member and an inner reinforcing member disposed between the rehabilitation pipe and the existing channel; and a filler material that is filled and solidified between the rehabilitation pipe and the existing channel, A method for designing the strength of a rehabilitation structure for an existing channel, characterized in that the strength design is performed using a structural design method employing a limit state design method, such that the rehabilitation structure alone has the strength to support the loads applied from around the existing channel, by ensuring that the outer peripheral reinforcing members of the rehabilitation section have sufficient strength against outer tensile failure caused by loads applied from around the existing channel, and that the inner peripheral reinforcing members of the rehabilitation section have sufficient strength against inner tensile failure.

2. The method for designing the strength of a rehabilitation structure for an existing channel according to claim 1, characterized in that a connecting member is provided on the annular reinforcing member, and the synthetic resin inner material of the rehabilitation pipe is provided on the connecting member.

3. A method for designing the strength of a rehabilitation structure for an existing channel according to any one of claims 1 to 2, characterized in that the annular reinforcing member is made of deformed reinforcing bars.

4. A method for designing the strength of a rehabilitation structure for an existing channel according to any one of claims 1 to 3, characterized in that a rail member extending in the axial direction of the existing channel is installed on the inner bottom side of the existing channel, and an annular reinforcing member is placed on the rail member.

5. A method for designing the strength of a rehabilitation structure for an existing channel according to any one of claims 1 to 4, characterized in that the center position of the outer peripheral reinforcing member is located at a position on the outer periphery that is 23 mm or more from the inner surface of the existing channel and no more than half the thickness of the filling material, and the center position of the inner peripheral reinforcing member is located at a position on the inner periphery that is 21 mm or more from the back surface of the rehabilitation pipe and no more than half the thickness of the filling material.

6. The strength design method for a rehabilitation structure of an existing channel according to any one of claims 1 to 5, characterized in that the side walls of the existing channel are made of stone masonry, a planar member is provided at the boundary between the filling material and the side walls of the existing channel, and a water conduit is provided at the boundary between the planar member and the existing channel, in the direction of the pipe axis of the rehabilitation pipe, for introducing water that has seeped in from the surrounding ground through the side walls of the existing channel. Law.

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