Underground pipe protection structure

Abstract

To suppress breakage of a pipe due to ground fluctuation.SOLUTION: The underground pipe protection structure includes an underground outer wall 40 covering an G1 of a wall surface of a foundation G, a path portion 60 extending from the underground outer wall 40 into the foundation G and forming an underground pipe path 52, a closing member 70 slidably pressed against an 60E of an opening end portion of the path portion 60 on the foundation G side and closing the opening 60E1, and a pipe 12 having a flexible portion 12B deformably accommodated in the underground pipe path 52 and buried in the foundation G through the underground outer wall 40, the underground pipe path 52, and the closing member 70.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an underground pipe protection structure. [Background technology]

[0002] BACKGROUND ART Piping structures in which pipes are buried in the ground are known (see, for example, Patent Documents 1 and 2).

[0003] Also, a piping structure in which piping is buried in concrete is known (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5437138 [Patent Document 2] Patent No. 4679402 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-173078 Summary of the Invention [Problem to be solved by the invention]

[0005] In some cases, pipes are laid through walls such as underground exterior walls or retaining walls that cover the ground and are then buried in the ground. In such cases, if the ground shifts relative to the wall due to subsidence or other reasons, the pipes may be deformed excessively at the boundary between the wall and the ground, potentially causing damage to the pipes.

[0006] In consideration of the above, the present invention aims to suppress damage to pipes caused by ground movement. [Means for solving the problem]

[0007] The underground piping protection structure described in claim 1 comprises a wall body covering the wall surface of the ground, a passage portion extending from the wall body into the ground and forming an underground piping passage, a blocking member slidably pressed against the opening end of the passage portion on the ground side and blocking the opening, and a piping having a flexible portion deformably accommodated in the underground piping passage, and buried in the ground through the wall body, the underground piping passage, and the blocking member.

[0008] According to the underground pipe protection structure of claim 1, the passage extends into the ground from a wall covering the wall surface of the ground, forming an underground pipe passage. A closing member is slidably pressed against the ground-side opening end of the passage. The closing member closes the ground-side opening of the passage. The pipe has a flexible portion that can be deformably accommodated in the underground pipe passage, and is buried in the ground through the wall, the underground pipe passage, and the closing member.

[0009] When the ground shifts due to subsidence or the like, the closing member slides relative to the open end of the passage, and the piping follows the sliding of the closing member, causing the flexible portion of the piping to deform in the underground piping passage within the passage.

[0010] In this way, when the ground moves, damage to the piping can be suppressed by deforming the flexible portion of the piping in the underground piping passage within the passage portion.

[0011] The underground pipe protection structure described in claim 2 is the underground pipe protection structure described in claim 1, and further includes a tension member connected to the wall body and the blocking member and pressing the blocking member against the open end of the passage portion.

[0012] According to the underground pipe protection structure of claim 2, the tendon is connected to the wall body and the closing member and presses the closing member against the open end of the passage. By increasing or decreasing the pressing force of the closing member against the open end of the passage using this tendon, it is possible to adjust the amount of sliding of the closing member during ground movement. As a result, it is also possible to adjust the amount of deformation of the flexible portion of the pipe that deforms in response to the closing member. Therefore, damage to the pipe due to ground movement can be further suppressed.

[0013] Furthermore, if the amount of sliding of the blocking member relative to the opening end of the passage section becomes excessive during ground movement, soil and sand may flow into the underground piping passage through the gap between the opening end of the passage section and the blocking member, hindering deformation of the flexible section of the piping.

[0014] In contrast, in the present invention, as described above, the sliding distance of the blocking member during ground movement is adjusted using the tension member, thereby making it possible to prevent soil and sand from flowing into the underground piping passage within the passage section.

[0015] The underground piping protection structure described in claim 3 is the underground piping protection structure described in claim 1 or claim 2, in which the passage portions have a plurality of annular members arranged in their respective axial directions and slidably pressed against each other to form the underground piping passage.

[0016] According to the underground pipe protection structure of claim 3, the passage portion has a plurality of annular members that form the underground pipe passage. The plurality of annular members are arranged in the axial direction of each other and are slidably pressed against each other.

[0017] As a result, the covering member and the plurality of annular members slide in response to ground movement, deforming the underground piping passage and the flexible section within the underground piping passage, thereby preventing damage to the piping due to ground movement.

[0018] Furthermore, when the passage section is formed by a single annular member, the deformation space of the flexible section required within the underground piping passage becomes large.

[0019] In contrast, in the present invention, as described above, by sliding the multiple annular members and deforming the underground piping passage in response to ground deformation, the deformation space required for the flexible section within the underground piping passage can be reduced, thereby enabling the passage to be made smaller.

[0020] The underground pipe protection structure according to a fourth aspect of the present invention is the underground pipe protection structure according to the third aspect, wherein the coefficient of friction between the annular member and the covering member is smaller than the coefficient of friction between adjacent annular members.

[0021] According to the underground pipe protection structure of claim 4, the coefficient of friction between the annular member and the closing member is smaller than the coefficient of friction between adjacent annular members. As a result, when ground deformation occurs, the closing member first slides relative to the open end of the passage, gradually deforming the flexible section of the pipe within the underground pipe passage. Then, as the amount of ground deformation increases, the multiple annular members slide, gradually deforming the underground pipe passage and the flexible section. Therefore, damage to the pipe due to ground deformation can be further suppressed. [Effects of the Invention]

[0022] As described above, according to the present invention, damage to pipes due to ground movement can be suppressed. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing a structure to which an underground pipe protection structure according to an embodiment is applied. [Figure 2] 2 is a partially enlarged cross-sectional view of FIG. 1 showing a passage unit according to one embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 2. [Figure 5] FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. [Figure 6]FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing a piping structure according to a comparative example. [Figure 7] FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing the behavior of the passage unit when the ground subsides. [Figure 8] FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing the behavior of the passage unit when the ground subsides. [Figure 9] FIG. 3 is a cross-sectional view corresponding to FIG. 2, showing the behavior of the passage unit when the ground subsides. [Figure 10] FIG. 6 is a cross-sectional view corresponding to FIG. 5, showing the behavior of the passage unit when the ground subsides. [Figure 11] 3 is a cross-sectional view corresponding to FIG. 2, showing a modified example of the underground pipe protective structure according to the embodiment. [Figure 12] 6 is a cross-sectional view corresponding to FIG. 5, showing a modified example of the underground pipe protecting structure according to the embodiment. [Figure 13] 4 is a cross-sectional view corresponding to FIG. 3, showing a modified example of a passage portion according to one embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment will be described with reference to the drawings.

[0025] (structure) FIG. 1 shows a structure 10 to which the underground piping protection structure according to this embodiment is applied. The structure 10 is, for example, a pile foundation. The structure 10 is, for example, a seismic isolation structure with underground foundation seismic isolation. The structure 10 includes an upper structure 20 and an underground structure 30.

[0026] The upper structure 20 is supported on the underground structure 30 via a plurality of seismic isolation devices 36, which will be described later. The upper structure 20 includes a footing 22 supported by the seismic isolation devices 36, a foundation beam 24 joined to the footing 22, and a first-floor slab 26 supported by the foundation beam 24.

[0027] The underground structure 30 has piles 32 buried in the ground, a foundation slab 34 supported by the piles 32, and an underground outer wall 40 rising from the outer periphery of the foundation slab 34 and defining an underground space 38. A seismic isolation device 36 is installed on the top surface of the foundation slab 34.

[0028] The seismic isolation device 36 is, for example, a laminated rubber bearing, and is installed in an underground space (seismic isolation layer) 38. The seismic isolation device 36 supports the upper structure 20 so as to be movable in the horizontal direction.

[0029] The underground exterior wall 40 is an earth retaining wall provided along a wall surface G1 of the ground G, and covers the wall surface G1. The underground exterior wall 40 is made of reinforced concrete, and has a plurality of wall reinforcements (not shown) buried inside. The underground exterior wall 40 is an example of a wall body.

[0030] A piping hole 42 is formed in the lower part of the underground outer wall 40. The piping hole 42 is a circular through-hole that penetrates the underground outer wall 40 in the thickness direction. A piping 12, which will be described later, is passed through this piping hole 42.

[0031] A pair of communication holes 44 are formed above the piping holes 42 in the underground outer wall 40. The pair of communication holes 44 are circular through-holes that penetrate the underground outer wall 40 in the thickness direction. The pair of communication holes 44 are also arranged with a gap between them in the width direction of the underground outer wall 40. Tendons 80, which will be described later, are slidably inserted into the pair of communication holes 44.

[0032] (Plumbing) The pipes 12 are, for example, pipes for infrastructure such as water supply and sewerage, gas, etc. The pipes 12 are buried in the ground G, and are drawn from the ground G into the underground structure 30 (underground space 38) through a pipe hole 42 in the underground outer wall 40, and are appropriately fixed to a frame or the like provided in the underground structure 30.

[0033] The piping 12 has two general sections 12A and a flexible section 12B. The two general sections 12A are formed from high-rigidity steel pipes or the like. Of the two general sections 12A, one general section 12A is buried in the ground G, and the other general section 12A is piped within the underground structure 30 (underground space 38). The two general sections 12A are connected by the flexible section 12B.

[0034] The flexible portion 12B is, for example, a seismic isolation joint or the like, and has flexibility. The flexible portion 12B has, for example, a bellows structure, and is deformable up, down, left, and right. This flexible portion 12B is piped to an underground pipe passage 52 in a passage unit 50, which will be described later. The underground pipe protection structure according to this embodiment is applied to the pipe 12 configured in this manner.

[0035] (Underground piping protection structure) As shown in Fig. 1, the underground pipe protection structure includes a passage unit 50. The passage unit 50 is an underground buried member that forms an underground pipe passage 52 through which a pipe 12 passes in the ground G. The axial length (total length) of the passage unit 50 (underground pipe passage 52) is set to X. The passage unit 50 includes a passage portion 60 and a closing member 70.

[0036] (passage, annular member) As shown in FIG. 2, the passage 60 has a plurality of (three in this embodiment) annular members 62. The annular members 62 are made of concrete. As an example, each annular member 62 is formed by a box culvert. Specifically, the annular members 62 are formed in a rectangular ring shape when viewed from the axial direction. Furthermore, both ends of the annular members 62 in the axial direction are open.

[0037] 3, each annular member 62 has a pair of side wall portions 62S, a lower wall portion 62L connecting the lower ends of the pair of side wall portions 62S, and an upper wall portion 62U connecting the upper ends of the pair of side wall portions 62S. A pair of communication holes 64 are formed in the upper portions of the end faces of the pair of side wall portions 62S.

[0038] The pair of communication holes 64 are through-holes that penetrate the pair of side wall portions 62S in the axial direction of the annular member 62. The pair of communication holes 64 are also elongated holes that extend in the vertical direction. Tendons 80, which will be described later, are slidably inserted into the pair of communication holes 64.

[0039] 2, the plurality of annular members 62 are arranged in the axial direction and are slidably pressed against one another by tendons 80, which will be described later. These annular members 62 form a passage 60. Inside the passage 60, an underground piping passage 52 is formed, through which the flexible portion 12B of the piping 12 passes.

[0040] The passageway 60 is buried in the ground G with one axial end abutting against the outer surface of the underground outer wall 40. In other words, the passageway 60 extends substantially horizontally from the underground outer wall 40 into the ground G, forming an underground piping passageway 52 in the ground G.

[0041] Furthermore, the passage section 60 is arranged so that the piping hole 42 in the underground outer wall 40 is connected to the lower part of the underground piping passage 52. In the initial state (standby state) before ground movement, the flexible section 12B of the piping 12 is housed (laid) in the lower part of this underground piping passage 52 so as to be deformable downward.

[0042] An opening 60E1 at the other end of the passage 60 in the axial direction, that is, the opening 60E1 on the ground G side of the passage 60 (the side opposite to the underground outer wall 40), is closed by a closing member .

[0043] (Blocking material) The blocking member 70 is made of concrete, for example. The blocking member 70 is formed by blocking an opening at one end of a box culvert, for example. Specifically, as shown in FIG. 4, the blocking member 70 is formed in a rectangular ring shape when viewed from the axial direction. The opening at one axial end of the blocking member 70 is blocked by a lid portion 70A.

[0044] The cover 70A is formed, for example, by pouring concrete into the opening of the covering member 70. A piping hole 72 leading to the underground piping passage 52 is formed in the lower part of the cover 70A. The piping hole 72 is a circular through-hole that penetrates the cover 70A in the thickness direction. The pipe 12 of the underground piping passage 52 is buried in the ground G (see FIG. 2) through the piping hole 72.

[0045] It is preferable that the piping hole 72 be appropriately sealed to prevent earth and sand from flowing into the underground piping passage 52.

[0046] 5, the blocking member 70 has a pair of side wall portions 70S, a lower wall portion 70L connecting the lower ends of the pair of side wall portions 70S, and an upper wall portion 70U connecting the upper ends of the pair of side wall portions 70S. A pair of communication holes 74 are formed in the upper portions of the end faces on the opening sides of the pair of side wall portions 70S.

[0047] The pair of communication holes 74 are holes with bottoms. The pair of communication holes 74 are elongated holes extending in the vertical direction. Tendons 80, which will be described later, are slidably inserted into the pair of communication holes 74.

[0048] The closing member 70 is buried in the ground G with the end opposite the lid portion 70A abutting against the open end 60E of the passage portion 60 on the ground G side. The closing member 70 forms the underground piping passage 52 together with the passage portion 60. The closing member 70 is also slidably pressed against the open end 60E of the passage portion 60 by a pair of tension members 80.

[0049] Here, the friction coefficients (static friction coefficients) of the contact surfaces (pressure contact surfaces) of adjacent underground outer walls 40, annular members 62, and blocking members 70 are set to decrease with increasing distance from the underground outer wall 40. Specifically, assuming that the friction coefficients of the contact surfaces of adjacent underground outer walls 40, annular members 62, and blocking members 70 are μ1, μ2, μ3, and μ4 in order from the underground outer wall 40, they are set as follows: μ1>μ2>μ3>μ4

[0050] The friction coefficients μ1, μ2, μ3, μ4 are adjusted by roughening the contact surfaces of the adjacent underground exterior wall 40, annular member 62, and closing member 70, or by providing a sliding material on the contact surfaces.

[0051] (Tension material) The pair of tendons 80 are formed of PC steel material such as PC steel rods or PC steel wires. The tendons 80 are slidably inserted into the plurality of annular members 62 and the pair of communication holes 64, 74 of the closing member 70. Each tendon 80 is movable up and down within the communication holes 64, 74.

[0052] In addition, in the initial state, each tendon 80 is disposed on the lower end side of each communication hole 64, 74. Furthermore, in the initial state, each tendon 80 is disposed above the piping 12 (flexible portion 12B) in the underground piping passage 52.

[0053] One end of the tendon 80 is fixed to the closing member 70. Specifically, an anchor 82 is provided at one end of the tendon 80. By embedding this anchor 82 in the closing member 70, one end of the tendon 80 is fixed to the closing member 70.

[0054] The method of fixing one end of the tendon 80 to the closing member 70 can be changed as appropriate.

[0055] The other end of the tendon 80 is slidably inserted into a communication hole 44 formed in the underground outer wall 40. While the tendon 80 is tensioned, the other end is fixed to the inner surface of the underground outer wall 40 by a fixing device 84. As a result, one end of the passage section 60 is slidably pressed against the outer surface of the underground outer wall 40, and the blocking member 70 is slidably pressed against the opening end 60E of the passage section 60.

[0056] (action) Next, the operation of this embodiment will be described.

[0057] First, a comparative example will be described. In the comparative example shown in Fig. 6, the pipe 12 is buried in the ground G through a pipe hole 42 formed in an underground outer wall 40. In this case, as shown by arrow Z, if the ground G moves relative to the underground outer wall 40 due to ground subsidence or the like, the deformation of the pipe 12 at the boundary between the underground outer wall 40 and the ground G becomes excessive, and the pipe 12 may be damaged.

[0058] In contrast, as shown in Fig. 2, in the underground pipe protection structure according to this embodiment, the passage 60 extends from the underground outer wall 40 covering the wall surface G1 of the ground G into the ground G to form the underground pipe passage 52. The passage 60 has a plurality of annular members 62 that form the underground pipe passage 52. The plurality of annular members 62 are arranged in the axial direction. An opening 60E1 of the passage 60 on the ground G side is blocked by a blocking member 70.

[0059] The pipe 12 has a flexible portion 12B that is deformably accommodated in the underground pipe passage 52, and is buried in the ground G through the underground outer wall 40, the underground pipe passage 52, and the closing member 70.

[0060] Here, a pair of tendons 80 are slidably inserted into the underground outer wall 40, the plurality of annular members 62, and a pair of communication holes 64, 74 of the blocking member 70. One end of the pair of tendons 80 is fixed to the blocking member 70.

[0061] In addition, the pair of tension members 80 are in a tensioned state, and the other ends thereof are fixed by fasteners 84 to the inner surface of the underground outer wall 40. As a result, the adjacent annular members 62 are slidably pressed against each other, and the blocking member 70 is slidably pressed against the opening end 60E of the passage portion 60.

[0062] In addition, the friction coefficients μ1, μ2, μ3, μ4 of the contact surfaces of adjacent underground outer walls 40, annular members 62, and blocking members 70 are set to decrease with increasing distance from the underground outer wall 40 (μ1>μ2>μ3>μ4).

[0063] 7, for example, when the ground G sinks, the blocking member 70 first slides downward relative to the open end 60E of the passage portion 60, and the piping 12 follows the sliding of the blocking member 70. As a result, in the underground piping passage 52 inside the passage portion 60, the flexible portion 12B of the piping 12 is gradually deformed with the underground outer wall 40 as a fulcrum.

[0064] Next, as shown in Figure 8, the third annular member 62 slides downward relative to the second annular member 62 from the underground outer wall 40. As a result, the blocking member 70 moves further downward relative to the underground outer wall 40, and the piping 12 follows the movement of the blocking member 70. As a result, in the underground piping passage 52 within the passage section 60, the flexible section 12B of the piping 12 further deforms with the underground outer wall 40 as a fulcrum.

[0065] Next, as shown in Figure 9, the second annular member 62 slides downward from the underground outer wall 40 relative to the first annular member 62. As a result, the blocking member 70 moves further downward relative to the underground outer wall 40, and the piping 12 follows the movement of the blocking member 70. As a result, in the underground piping passage 52 within the passage section 60, the flexible section 12B of the piping 12 further deforms with the underground outer wall 40 as a fulcrum.

[0066] In this way, when ground deformation such as land subsidence occurs, damage to the pipe 12 can be suppressed by deforming the flexible portion 12B of the pipe 12 in the underground pipe passage 52 having the length X. Furthermore, by increasing the length X of the underground pipe passage 52 (passage unit 50), damage to the pipe 12 can be further suppressed.

[0067] Furthermore, in this embodiment, as described above, the friction coefficients μ1, μ2, μ3, μ4 of the contact surfaces of adjacent underground outer walls 40, annular members 62, and blocking members 70 are set to decrease with increasing distance from the underground outer wall 40 (μ1>μ2>μ3>μ4).

[0068] As a result, when the ground subsides, the blocking member 70 is first slid against the opening end 60E of the passage portion 60, as shown in Figure 7, and the flexible portion 12B of the pipe 12 can be gently deformed within the underground pipe passage 52.

[0069] 8 and 9, as the amount of deformation of the ground G increases, the adjacent annular members 62 can be slid to gradually deform the underground piping passage 52 and the flexible section 12B. Therefore, damage to the piping 12 due to ground subsidence can be further suppressed.

[0070] In this embodiment, the friction coefficient μ1 is set so that the first annular member 62 does not slide downward relative to the underground outer wall 40. However, the first annular member 62 may be allowed to slide downward relative to the underground outer wall 40.

[0071] Furthermore, in this embodiment, the pair of tendons 80 can be used to increase or decrease the pressure between adjacent underground outer walls 40, the plurality of annular members 62, and the closing member 70, thereby adjusting the amount of sliding of the plurality of annular members 62 and the closing member 70 during ground movement. As a result, the amount of deformation of the flexible section 12B of the piping 12, which deforms in response to the closing member 70, can also be adjusted. Therefore, damage to the piping 12 due to ground movement can be further suppressed.

[0072] 10, as the closing member 70 moves downward (sinks) relative to the underground outer wall 40, the tensile force (axial force) acting on the tendon 80 increases. As a result, the pressing force of the closing member 70 against the opening end 60E of the passage 60 gradually increases, and as a result, the frictional force generated between the opening end 60E of the passage 60 and the closing member 70 also gradually increases. Taking this frictional force into consideration, it is possible to adjust the sliding amount of the closing member 70 relative to the opening end 60E of the passage 60.

[0073] Similarly, as the tensile force (axial force) acting on the tendon 80 increases, the frictional force generated between adjacent annular members 62 and between the underground outer wall 40 and the annular member 62 also gradually increases. Taking this frictional force into consideration, it is also possible to adjust the amount of sliding between adjacent annular members 62.

[0074] However, if the amount of sliding between adjacent annular members 62 and blocking members 70 or between adjacent annular members 62 becomes excessive during ground movement, soil and sand may flow into the underground piping passage 52 through the gaps between adjacent annular members 62 and blocking members 70 or the gaps between adjacent annular members 62, which may hinder deformation of the flexible section 12B of the piping 12.

[0075] In contrast to this, in this embodiment, as described above, the pair of tension members 80 can be used to adjust the sliding amount of the annular member 62 and the blocking member 70 during ground movement, thereby preventing soil and sand from flowing into the underground piping passage 52 in the passage section 60.

[0076] Furthermore, for example, when the passage portion 60 is formed by one annular member having a long axial length (total length), the deformation space required for the flexible portion 12B inside the underground piping passage 52 becomes large.

[0077] In contrast to this, in this embodiment, the passage 60 is formed by a plurality of annular members 62. As a result, by sliding adjacent annular members 62 and deforming the underground piping passage 52 in response to ground deformation, it is possible to reduce the deformation space required for the flexible section 12B within the underground piping passage 52. Therefore, it is possible to reduce the size of the passage 60.

[0078] Furthermore, in this embodiment, a pair of tendons 80 are provided above the passage portion 60 and the closing member 70. In the initial state, the pair of tendons 80 are arranged above the pipe 12 (flexible portion 12B) in the underground pipe passage 52.

[0079] As a result, in this embodiment, it is easier to control the amount of sliding (amount of subsidence) of the passage portion 60 and the closing member 70 due to ground subsidence, compared to when a pair of tendons 80 is provided below the passage portion 60 and the closing member 70. Therefore, damage to the piping 12 due to ground subsidence can be further suppressed.

[0080] (Variation) Next, a modification of the above embodiment will be described.

[0081] In the above embodiment, the passage portion 60 and the closing member 70 of the passage unit 50 are pressed together by a so-called post-tensioning tendon 80. However, the passage portion 60 and the closing member 70 of the passage unit 50 may be pressed together by a pre-tensioning tendon 80.

[0082] 11 and 12, for example, a pair of tendons 80 are tensioned, and their other ends are fixed to the first annular member 62 from the underground outer wall 40. The pair of tendons 80 press the passage 60 and the blocking member 70 together.

[0083] This allows the passage portion 60 and the blocking member 70 to be pressed together before the passage unit 50 is installed underground, thereby improving the workability of the passage unit 50. Note that one annular member 62 from the underground outer wall 40 is fixed to the underground outer wall 40 by a fixing device 90.

[0084] Furthermore, the passage unit 50 according to the above embodiment is configured to be able to suppress damage to the piping 12 mainly due to ground subsidence. However, the passage unit 50 according to the above embodiment may be configured to suppress damage to the piping 12 not only due to ground subsidence but also due to, for example, ground uplift or lateral movement.

[0085] For example, in the modified example shown in Fig. 13, the width of the underground piping passage 52 in the passage section 60 is increased. The flexible section 12B of the piping 12 is accommodated in the center of the underground piping passage 52 so as to be deformable in the vertical and horizontal directions.

[0086] This allows the flexible portion 12B of the piping 12 to deform vertically and horizontally in response to ground movements such as ground subsidence, ground uplift, lateral movement, etc. Therefore, similar to the above embodiment, damage to the piping 12 due to ground movements can be suppressed.

[0087] Furthermore, a pair of tendons 80 are provided above and below the passage section 60 and the closing member 70 (see FIG. 2), respectively. In the initial state, the pair of tendons 80 provided above the passage section 60 and the closing member 70 are positioned above the piping 12 (flexible section 12B) in the underground piping passage 52. Therefore, similar to the above embodiment, it becomes easier to control the amount of sliding (amount of subsidence) of the passage section 60 and the closing member 70 due to ground subsidence.

[0088] Meanwhile, the pair of tendons 80 provided below the passage section 60 and the closing member 70 are initially positioned below the piping 12 (flexible section 12B) in the underground piping passage 52. This makes it easier to control the amount of sliding (amount of lift) of the passage section 60 and the closing member 70 that occurs with the uplift of the ground. Therefore, damage to the piping 12 due to ground movement can be further suppressed.

[0089] Furthermore, in the above embodiment, the friction coefficient of the contact surfaces of adjacent underground outer walls 40, annular members 62, and blocking members 70 is set to decrease with increasing distance from the underground outer wall 40. However, the friction coefficient of the contact surfaces of adjacent underground outer walls 40, annular members 62, and blocking members 70 can be changed as appropriate. For example, the friction coefficient of the contact surfaces of adjacent annular members 62 may be set to the same, and the friction coefficient of the contact surfaces of the annular members 62 and blocking members 70 may be set to be smaller than the friction coefficient. Furthermore, the friction coefficients of the contact surfaces of adjacent underground outer walls 40, annular members 62, and blocking members 70 may all be set to the same.

[0090] Furthermore, in the above embodiment, the passage portion 60 of the passage unit 50 is formed by a plurality of annular members 62. However, the passage portion 60 is not limited to a plurality of annular members 62, and may be formed by, for example, one annular member having a length equivalent to that of three annular members 62. In other words, the passage portion 60 can be formed by at least one annular member.

[0091] Furthermore, in the above embodiment, the blocking member 70 is formed in an annular shape. However, the blocking member 70 is not limited to an annular shape. The blocking member 70 may be formed in any shape as long as it is capable of blocking the opening 60E1 of the passage portion 60, and may be formed in a flat plate shape, for example. Note that if the blocking member 70 is formed in a flat plate shape, the underground piping passage 52 is not formed within the blocking member 70. In other words, the underground piping passage 52 can be formed at least within the passage portion.

[0092] In the above embodiment, one pipe 12 is installed in the underground piping passage 52 in the passage unit 50. However, the number of pipes 12 installed in the underground piping passage 52 in the passage unit 50 is not limited to one, and multiple pipes 12 may be installed.

[0093] In the above embodiment, the underground space 38 partitioned by the underground outer wall 40 is a seismic isolation layer. However, the underground space partitioned by the underground outer wall 40 is not limited to a seismic isolation layer, and may be, for example, an underground pit, a basement, an underground parking lot, or the like.

[0094] In the above embodiment, the structure 10 is a seismically isolated structure. However, the structure 10 is not limited to a seismically isolated structure and may be a non-seismically isolated structure. Furthermore, the structure 10 only needs to include at least the underground structure 30, and the upper structure 20 may be omitted as appropriate.

[0095] Furthermore, the above embodiment is applied to the piping 12 that penetrates the underground outer wall 40 from the ground G and is drawn into the underground structure 30. However, the above embodiment is not limited to the piping 12 that is drawn from the ground G into the underground structure 30, and may also be applied to, for example, a piping that is drawn from the ground into an underground water tank. In this case, the underground outer wall (tank body) of the underground water tank that covers the wall surface of the ground is an example of a wall.

[0096] The above-described embodiment can also be applied to, for example, a pipe that is pulled out of the ground and laid along a civil engineering structure such as a bridge. In this case, a retaining wall or the like that covers the wall surface of the ground is an example of a wall body.

[0097] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modified examples may be used in appropriate combination, and it goes without saying that the present invention can be implemented in various forms as long as it does not deviate from the gist of the present invention. [Explanation of symbols]

[0098] 12 Piping 12B flexible part 40 Underground outer wall (wall) 52 Underground piping passage 60 Passage section 60E Open end 60E1 aperture 62 Annular member 70 Closing member 80 Tensile material G Ground G1 Wall

Claims

1. A wall covering the ground wall; a passage portion extending from the wall body into the ground and forming an underground piping passage; a closing member that is slidably pressed against the ground-side opening end of the passage portion and closes the opening; a pipe having a flexible portion that is deformably accommodated in the underground pipe passage, the pipe being buried in the ground through the wall body, the underground pipe passage, and the closing member; An underground piping protection structure comprising:

2. a tension member connected to the wall body and the closing member and pressing the closing member against the open end of the passage portion; The underground piping protection structure according to claim 1 .

3. The passage portion has a plurality of annular members arranged in the axial direction and slidably pressed against each other to form the underground piping passage. The underground piping protection structure according to claim 1 or 2.

4. a coefficient of friction between the annular member and the blocking member is smaller than a coefficient of friction between adjacent annular members; The underground piping protection structure according to claim 3 .

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