Flexible joint

Abstract

To provide a flexible joint capable of suppressing local strain generated in an expansion member at low cost.SOLUTION: A flexible joint 1 provided at a joint part of a concrete structure 60 includes an expansion / contraction member 10 having an expansion / contraction part for expanding / contracting the flexible joint 1 at the center and provided so that the expansion / contraction part straddles the joint part, and pressing members 40 arranged on both sides across the joint part and pressing mounting parts 12 set outside the expansion / contraction part to press the expansion / contraction member 10 against the concrete structure 60. In the expansion / contraction member 10, a projection part 13 for increasing thickness is formed at a position adjacent to the center side of the mounting part 12, and the rising angle of the projection part 13 from the mounting part 12 side is steeper than the rising angle from the expansion / contraction part side.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a flexible joint. [Background technology]

[0002] Flexible joints are provided in the joints of concrete structures such as waterways, water tanks, and culverts constructed underground, such as utility sewer systems, to stop water from entering and to allow for uneven settlement of the concrete structures on both sides of the joint, displacement during an earthquake, etc. For example, Patent Document 1 discloses such a flexible joint, which is made up of an expansion member that constitutes the main body of the flexible joint, a clamp for the expansion member, and a fastener. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-106294 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the water pressure from the water flowing out of the joints acts on the expansion member of Patent Document 1, large local strains tend to occur at the boundary between the area of ​​the expansion member held down by the metal fittings and the area where the water pressure acts. Such local strains are also likely to occur when the concrete structure is displaced. To reduce local strains, methods such as placing reinforcing fabric inside the expansion member or using steel materials to hold down the deformation of the expansion member have been used, but these methods increase costs.

[0005] The present invention has been made in light of these problems, and has as its object to provide a flexible joint that can suppress local strain occurring in an expandable member at low cost. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the flexible joint of the present invention is a flexible joint that is installed in a joint portion of a concrete structure, and comprises an expansion / contraction member that has an expansion / contraction section in the center that expands and contracts the flexible joint, and the expansion / contraction section is installed so that it straddles the joint portion, and pressing members that are arranged on both sides of the joint portion and press against mounting sections set on the outside of the expansion / contraction section to press the expansion / contraction member against the concrete structure, and the expansion / contraction member has a protrusion that increases its thickness at a position adjacent to the center of the mounting section, and the rise angle of the protrusion from the mounting section side is steeper than the rise angle from the expansion / contraction section side.

[0007] The surface of the protrusion facing the mounting portion may be perpendicular to the mounting portion and may face the end face of the pressing member with a gap therebetween.

[0008] A gap between the protruding portion and the pressing member may be smaller than a protruding amount of the protruding portion.

[0009] A protective cloth may be provided to cover the elastic member, and the edge of the protective cloth may be passed between the surface of the protrusion on the mounting portion side and the end face of the pressing member, and may be sandwiched between the pressing member and the elastic member.

[0010] In order to achieve the above-mentioned object, another flexible joint of the present invention is a flexible joint that is installed in a joint portion of a concrete structure, and comprises an expansion / contraction section that expands and contracts the flexible joint, an expansion section that extends from both ends of the expansion section, and a bending section that is bent from the end of each of the extension sections, and pressing members that are attached to opposing opposing surfaces of the concrete structure, wherein the pressing members have a first pressing section that presses the bending section against the opposing surface, and a second pressing section that intersects with the first pressing section and contacts a part of the extension section, and a protrusion that increases the thickness is formed on the extension section at a position adjacent to the second pressing section, and the rise angle of the protrusion from the second pressing section side is steeper than the rise angle from the expansion / contraction section side. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a flexible joint that can suppress local strain occurring in an expandable member at low cost. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view showing a part of a flexible joint according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of a flexible joint according to a first embodiment of the present invention. [Figure 3] FIG. 3 is an enlarged view of part “III” in FIG. 2. [Figure 4] 4 is a diagram showing how water pressure acts on the flexible joint shown in FIG. 3. FIG. [Figure 5] FIG. 6 is a cross-sectional view of a flexible joint according to a second embodiment of the present invention. [Figure 6] 5A and 5B show flexible joints according to other embodiments of the present invention, where FIG. 5A is a cross-sectional view of a flexible joint according to a third embodiment, and FIG. 5B is a cross-sectional view of a flexible joint according to a fourth embodiment. [Figure 7] FIG. 10 is a cross-sectional view of a flexible joint according to a fifth embodiment of the present invention. [Figure 8] The strain generated in the elastic member was calculated by numerical analysis, where (a) shows the results for an elastic member without protrusions, and (b) shows the results for an elastic member with protrusions. DETAILED DESCRIPTION OF THE INVENTION

[0013] A flexible joint according to an embodiment of the present invention will be described below with reference to the drawings. The concrete structure 60 shown in Fig. 1 is, for example, a utility tunnel that houses infrastructure facilities such as telephone, electricity, gas, and water. A Z-axis is set perpendicular to the surface of the concrete structure 60, and X- and Y-axes are set parallel to the surface of the concrete structure 60 and perpendicular to each other. The Y-axis coincides with the extension direction of a joint 61 of the concrete structure 60.

[0014] (Embodiment 1) 1 and 2, the flexible joint 1 according to the first embodiment is provided so as to cover a joint 61 of a concrete structure 60. The flexible joint 1 includes an expansion / contraction member 10, a water-stopping material 20 interposed between the expansion / contraction member 10 and the surface of the concrete structure 60, anchor bolts 30 installed in line in the longitudinal direction of the flexible joint 1, and a pressing member 40 for pressing the expansion / contraction member 10 against the concrete structure 60.

[0015] The elastic member 10 has a longitudinal direction in the direction in which the joint portion 61 extends (Y-axis direction), and is installed so as to cover the joint portion 61. The elastic member 10 is made of an elastic material, such as chloroprene rubber. As shown in FIG. 2 , the elastic member 10 has elastic portions 11 that are installed so as to straddle the joint portion 61, mounting portions 12 that are installed on both sides of the elastic member 10 and are pressed against the pressing member 40 to be attached to the concrete structure 60, and protrusions 13 that increase the thickness of the elastic member 10 between the elastic portions 11 and the mounting portions 12.

[0016] The expansion and contraction section 11 is bent in a curved state so that it can follow the displacement of the concrete structures 60 on both sides to which the flexible joint 1 is attached. The expansion and contraction section 11 has a substantially V-shape, and the expansion and contraction member 10 expands and contracts by being stretched and bent.

[0017] The mounting portions 12 are attached to the concrete structures 60 on both sides. When viewed in the longitudinal direction as shown in FIG. 2, the flexible joint 1 has a bilaterally symmetrical configuration with respect to a center line (not shown) extending in the up-down direction. Therefore, the following will describe the configuration of the flexible joint 1 on the right side in FIG. 2, and will not describe the overlapping configuration on the left side. The mounting portion 12 is a rectangular portion with its longitudinal direction in the Y-axis direction, and is formed with a plurality of bolt insertion holes 12a for inserting anchor bolts 30 in the longitudinal direction. A pressing member 40 is placed on the +Z side surface of the mounting portion 12, and when nuts 31 are tightened onto the anchor bolts 30, the pressing member 40 presses the mounting portion 12 against the concrete structure 60.

[0018] The protrusion 13 protrudes in the +Z direction from the +Z side surface of the expandable member 10. The protrusion 13 extends in the longitudinal direction (Y-axis direction), and the cross-sectional shape and size are constant in the longitudinal direction.

[0019] The waterstop material 20 is a long, rectangular rubber material, and is made of, for example, butyl rubber. The waterstop material 20 is arranged in contact with the -Z side surface of the mounting portion 12. The waterstop materials 20 are arranged in two rows, sandwiching the anchor bolt 30 between them. That is, the waterstop materials 20 are arranged with their longitudinal direction oriented along the Y axis, with gaps in the X axis direction provided for the anchor bolt 30 to pass through. The waterstop material 20 is provided between the concrete structure 60 and the mounting portion 12.

[0020] The anchor bolts 30 are so-called adhesive anchors, and are fixed by filling holes drilled in the concrete structure 60 with adhesive. The anchor bolts 30 are driven into the concrete structure 60 on both sides of the joint 61 along the longitudinal direction (Y-axis direction).

[0021] The pressing member 40 is a long, rectangular plate member. The pressing member 40 is made of, for example, stainless steel. A bolt insertion hole 40a is formed in the pressing member 40 to insert the anchor bolt 30 in the longitudinal direction. The pressing member 40 is placed on the +Z side surface of the mounting portion 12. The mounting portion 12 is pressed against the concrete structure 60 by tightening the nut 31 screwed onto the anchor bolt 30. In this way, the flexible joint 1 is fixed to the concrete structure 60. At this time, the water-stopping material 20 is interposed between the concrete structure 60 and the mounting portion 12, and blocks water that flows out from the joint portion 61.

[0022] Next, the protrusion 13 provided on the telescopic member 10 will be described in more detail. The protrusion 13 protrudes in the +Z direction between the telescopic portion 11 and the mounting portion 12. Therefore, the thickness of the telescopic member 10 increases in the region where the protrusion 13 is formed. As shown in FIG. 3, the protrusion 13 has a rising surface 13a that rises vertically from the +Z side surface of the mounting portion 12, a tip surface 13b that connects to the rising surface 13a and forms the +Z side end surface of the protrusion 13, and an arc-shaped connecting surface 13c that is a downwardly convex arc-shaped surface extending from the tip surface 13b and connects to the telescopic portion 11. The tip surface 13b is parallel to the XY plane. As such, the angle of the rising surface 13a on the mounting portion 12 side of the protrusion 13 abruptly changes, and the rising angle θ1 with the +Z side surface of the mounting portion is 90 degrees. On the other hand, the rise angle θ2 of the arcuate connecting surface 13c of the protrusion 13 on the expandable portion 11 side gradually increases from 0 degrees as it connects to the tip surface 13b. That is, the protrusion 13 has a shape in the X-axis direction where the outer side (the side where the mounting portion 12 is located) rises sharply and the inner side (the side where the expandable portion 11 is located) rises gradually. In this way, the rise angle of the protrusion 13 from the mounting portion 12 side is steeper than the rise angle from the expandable portion 11 side.

[0023] The protrusion amount H of the protrusion 13 in the +Z direction is smaller than the thickness t1 of the pressing member 40. For example, the protrusion amount H is about half the thickness t1 of the pressing member 40. Moreover, the protrusion amount H is about 0.4 times the thickness t2 of the mounting portion 12.

[0024] Furthermore, a gap G is provided in the X-axis direction between the protrusion 13 and the pressing member 40 across the longitudinal direction (Y-axis) of the flexible joint 1. The gap G is smaller than the protrusion amount H of the protrusion 13 in the +Z direction. For example, the gap G is set to a size approximately 0.15 times the protrusion amount H.

[0025] Suppose water leaks out from a joint 61 (FIGS. 1 and 2) covered by a flexible joint 1 having such an expandable member 10. The water leaking from the joint 61 is blocked by the expandable member 10 and the water-stopping material 20 formed between the expandable member 10 and the concrete structure 60. This prevents water from leaking out of the flexible joint 1. The water leaking from the joint 61 is pooled between the expandable member 10 and the concrete structure 60, and as shown by the arrow in FIG. 4, water pressure acts on the -Z side surface of the expandable member 10. This causes the expandable member 10 to deform toward the +Z side. This deformation of the expandable member 10 occurs in a non-pressured region 51, which is an area inside the pressed region 50 pressed by the presser member 40. Here, the non-pressured region 51 is an area not pressed by the presser member 40. When the non-compressed region 51 deforms toward the +Z side in this way, the boundary between the compressed region 50 and the non-compressed region 51 of the telescopic member 10 is bent in a downwardly convex manner in Figure 4. At this time, a local strain generation area 53 where a large tensile strain occurs locally tends to be formed at the lower end. Such a local strain generation area 53 is likely to be formed not only by the action of the water pressure of water leaking from the joint area 61, etc., but also when the concrete structure 60 is displaced, etc., and the telescopic member 10 is pulled diagonally upward by a force T. In the telescopic member 10, a protrusion 13 that increases the thickness of the telescopic member 10 is formed at the location of the local strain generation area 53 where such a large local strain is likely to occur.

[0026] As has been specifically described above regarding the embodiments, the flexible joint 1 according to embodiment 1 of the present invention is a flexible joint 1 provided in a joint portion 61 of a concrete structure 60, and has an expansion / contraction section 11 in the center that expands and contracts the flexible joint 1, and is provided with an expansion / contraction member 10 that is provided so that the expansion / contraction section 11 straddles the joint portion 61, and pressing members 40 that are arranged on both sides of the joint portion 61 and press against mounting portions 12 set on the outside of the expansion / contraction section 11 to hold the expansion / contraction member 10 against the concrete structure 60, and a protrusion 13 that increases the thickness is formed in the expansion / contraction member 10 at a position adjacent to the center of the mounting portion 12, and the rise angle of the protrusion 13 from the mounting portion 12 side is steeper than the rise angle from the expansion / contraction section 11 side.

[0027] According to this configuration, protrusions 13 that increase the thickness of the expandable member 10 are formed in locations where local strain is likely to occur in the expandable member 10 when the water pressure of water leaking from the joints 61 acts on the expandable member 10, or when the concrete structure 60 is displaced and the flexible joint follows the displacement. This increases the rigidity of the expandable member 10 in areas where local strain is likely to occur, reducing the deformation of the local strain-generating area 53 and the amount of strain that occurs. In addition, the rise angle of the protrusions 13 from the mounting portion 12 side is steeper than the rise angle from the expandable portion 11 side. This allows the portion closer to the expandable portion 11 than the protrusions 13 to be smoothly bent and deformed, making it less likely that abrupt changes in bending will occur, resulting in local strain.

[0028] The surface of the protruding portion 13 on the mounting portion 12 side is perpendicular to the mounting portion 12 and is configured to face the end face of the pressing member 40 with a gap therebetween.

[0029] With this configuration, when the expandable member 10 expands due to water pressure or is pulled and deformed due to displacement of the concrete structure 60, the protrusion 13 can be leaned against the end face 40b of the pressing member 40 as shown in Figure 4, thereby preventing further displacement of the protrusion 13. This makes it possible to restrict bending deformation of the local strain generation part 53 and suppress local strain generated in the expandable member 10.

[0030] The gap between the protruding portion 13 and the pressing member 40 is configured to be smaller than the protruding amount of the protruding portion 13.

[0031] With this configuration, when the expandable member 10 expands due to water pressure or is pulled and deformed due to displacement of the concrete structure 60, the protrusion 13 can be easily leaned against the end surface 40b of the pressing member 40. This makes it possible to restrict bending deformation of the local strain generation part 53, and suppress local strain generated in the expandable member 10.

[0032] The present invention is not limited to the above-described embodiment, and various modifications and applications are possible.

[0033] (Embodiment 2) Next, a flexible joint 101 according to a second embodiment will be described with reference to Fig. 5. The flexible joint 101 shown in Fig. 5 differs from the flexible joint 1 (Fig. 1) of the above embodiment in that the expansion section 111 of the expansion member 110 has an increased number of folds, forming a bellows shape, and in that a protective cloth 170 is provided to protect the expansion member 110. However, since there are many components in common with the above embodiment, the common components are denoted by the same reference numerals, and a description of the common components will be omitted.

[0034] The elastic member 110 has an accordion-shaped elastic portion 111 that is folded back multiple times. The elastic portion 111 has two arc portions that are convex in the +Z-axis direction and one arc portion that is convex in the -Z-axis direction. Because the elastic member 110 has an accordion-shaped elastic portion 111 that is folded back multiple times, the amount of expansion and contraction in the X-axis direction is greater than that of the elastic member 10 of the first embodiment (FIG. 2).

[0035] The protective cloth 170 covers the elastic member 110 to protect the elastic member 110. Both edge portions 170a of the protective cloth 170 in the X-axis direction are sandwiched between the presser member 40 and the elastic member 110, and pass through the gap between the presser member 40 and the protruding portion 13 to cover the elastic member 110. The protective cloth 170 is provided with a folding portion 171 so as to accommodate the expansion and contraction of the elastic member 110.

[0036] The flexible joint 101 according to the second embodiment of the present invention is provided with a protective cloth 170 that covers the elastic member 110, and the edges of the protective cloth 170 (both edges 170a) are passed between the surface of the protrusion 13 on the mounting portion 12 side (rising surface 13a (Figure 3)) and the end surface 40b (Figure 4) of the pressing member 40, and are clamped between the pressing member 40 and the elastic member 110.

[0037] 4, the protruding portion 13 leans against the end surface 40b of the pressing member 40, thereby sandwiching the protective cloth 170 between the protruding portion 13 and the pressing member 40. In this way, the pressing force of the protruding portion 13 prevents the protective cloth 170 from coming off.

[0038] (Embodiment 3) Next, a flexible joint 201 according to a third embodiment will be described with reference to Fig. 6(a). In this embodiment, the anchor bolt 30 is not passed through the expansion / contraction member 210, and the expansion / contraction member 210 is pressed against the concrete structure 60 by a pressing member 240 that is fastened via the anchor bolt 30. In this way, the method of attaching the expansion / contraction member 210 differs from the above-described embodiments.

[0039] The flexible joint 201 includes an expandable member 210, a water-stopping material 220 interposed between the expandable member 210 and the surface of the concrete structure 60, anchor bolts 30 installed in line along the longitudinal direction of the flexible joint 201, a pressing member 240 for pressing the expandable member 210 against the concrete structure 60, and a fixing member 270 for fixing the pressing member 240.

[0040] The fixing member 270 has a pair of pressing arms 271 spaced apart in the Y-axis direction, and an intermediate plate-shaped portion 272 connecting the pair of pressing arms 271. A bolt hole (not shown) for the anchor bolt 30 is formed in the intermediate plate-shaped portion 272. The fixing member 270 is made of, for example, stainless steel.

[0041] The pressing member 240 has, for example, a cross section of a generally U-shaped lip groove shape that is open at the top, and the cross-sectional shape and size are constant in the longitudinal direction (Y-axis direction). The pressing member 240 is provided on the mounting portion 212 so that a mounting surface 240b that faces the surface on which the opening 240a is formed comes into contact with the mounting portion 212.

[0042] The expandable member 210 has an accordion-shaped expandable section 211 that is folded back multiple times, mounting sections 212 that are provided on both sides of the expandable section 211 and are pressed against the holding member 240 to be attached to the concrete structure 60, protrusions 13 that are formed between the expandable section 211 and the mounting sections 212 and increase the thickness of the expandable member 210, and raised edge sections 214 that are provided on both sides of the expandable member 210. The shape and size of the protrusions 13 and the gap between the protrusions 13 and the holding member 240 are the same as in the above embodiment.

[0043] The pressing member 240 is installed on the mounting portion 212 between the protrusion 13 and the flange portion 214. By placing a pair of pressing arms 271 on the pressing member 240 and tightening the nut 31 of the anchor bolt 30, the fixing member 270 presses the mounting portion 212 via the pressing member 240.

[0044] In this way, even if the pressing member 240 is not a plate-shaped member that is fastened with an anchor bolt, but is configured to have a lip groove-shaped cross section, by forming a protrusion 13 that protrudes from the surface of the expandable member 210 in the vicinity thereof, the same effect as that described in embodiment 1 can be obtained.

[0045] (Fourth embodiment) Next, a flexible joint 301 according to a fourth embodiment will be described with reference to Fig. 6(b). The flexible joint 301 differs from the flexible joint 1 of the first embodiment shown in Fig. 2 in the method of fixing the expansion member 310. That is, no anchor bolts 30 are passed through the expansion member 310 of the flexible joint 301, and the expansion member 310 is pressed and fixed against the concrete structure 60 by a presser member 340 tightened by the anchor bolts 30.

[0046] The elastic member 310 has a substantially V-shaped elastic portion 311, attachment portions 312 formed on both ends of the elastic member 310 in the X-axis direction, and a protrusion 13 formed between the elastic portion 311 and the attachment portion 312 and protruding toward the +Z side. The protrusion mode of the protrusion 13 is the same as in the above embodiment.

[0047] The attachment portions 312 are convex portions with a rectangular cross section that rise in the +Z direction from both ends of the expandable member 310. The attachment portions 312 extend in the longitudinal direction (Y-axis direction), and the cross-sectional shape and size are constant in the longitudinal direction.

[0048] The pressing member 340 has a flat portion 341 that is fastened by the anchor bolt 30 on the outside of the expansion and contraction member 310, and a grooved portion 342 formed on the edge of the flat portion 341. A bolt hole (not shown) through which the anchor bolt 30 passes is formed in the flat portion 341. The grooved portion 342 is a channel-shaped portion with an opening on the bottom, into which the mounting portion 312 is fitted. With the grooved portion 342 fitted into the mounting portion 312, the nut 31 is tightened onto the anchor bolt 30. In this way, the pressing member 340 presses the expansion and contraction member 310 against the concrete structure 60, fixing it in place.

[0049] The protrusion 13 is provided with a gap between it and the side plate portion 342a at the edge of the grooved portion 342. This gap is the same as the gap G described with reference to FIG.

[0050] In this way, the pressing member 340 is fastened via the anchor bolts 30 on the outside of the expandable member 310, and the grooved portion 342 formed on the edge presses down on the expandable member 310. Even with this configuration, by forming a protrusion 13 that protrudes from the surface of the expandable member 310 near the side plate portion 342a of the grooved portion 342, it is possible to obtain the same effect as that described in the first embodiment.

[0051] (Embodiment 5) Next, a flexible joint 401 according to a fifth embodiment will be described with reference to Fig. 7. In Fig. 7, the direction in which the opposing surface 63a of the concrete structure 63 and the opposing surface 64a of the concrete structure 64 face each other is defined as the X-axis direction, the direction perpendicular to the X-axis direction and in which the joint portion 65 extends is defined as the Y-axis direction, and the depth direction of the recessed portion 66 formed in the concrete structures 63 and 64 is defined as the Z-axis direction, and these axial directions will be used appropriately in the description.

[0052] The flexible joint 401 is provided, for example, at the joint between an existing concrete structure 63 and a newly constructed concrete structure 64. A recess 66 for accommodating the flexible joint 401 is formed between the concrete structures 63 and 64. This recess 66 is defined by an opposing surface 63a of the concrete structure 63, an opposing surface 64a of the concrete structure 64 opposing the opposing surface 63a, an orthogonal surface 64b that is orthogonal to the opposing surface 64a and extends from the opposing surface 64a toward the opposing surface 63a, and a joint portion 65 that closes the gap between the concrete structures 63 and 64.

[0053] The flexible joint 401 has a pressing member 440 attached to the opposing surface 63a and the opposing surface 64a, and an expandable member 410 attached to the concrete structures 63, 64 by the pressing member 440. Note that the two pressing members 440 shown in Fig. 7 have a symmetrical configuration, so the following will explain the configuration of the pressing member 440 on the right side.

[0054] The holding member 440 has a first holding portion 441 and a second holding portion 442 attached to an end of the first holding portion 441 and intersecting with the first holding portion 441. In the present embodiment, the first holding portion 441 and the second holding portion 442 are perpendicular to each other, but the angle of intersection is not limited to being perpendicular because it is adjusted to the shape of the recess 66. An anchor bolt insertion hole (not shown) through which the anchor bolt 30 is inserted is formed in the first holding portion 441.

[0055] The elastic member 410 has an elastic portion 411 having an approximately U-shaped cross section, extension portions 412 extending left and right from both ends of the elastic portion 411 having an approximately U-shaped cross section, and attachment portions 413 (bent portions) extending in the +Z direction from each tip of the extension portions 412 and pressed by the pressing member 440.

[0056] One mounting portion 413 is pressed against the opposing surface 63a by the first pressing portion 441 on the right side in Fig. 7. The other mounting portion 413 is pressed against the opposing surface 64a by the first pressing portion 441 on the left side in Fig. 7. In this way, the expandable member 410 is fixed in the recess 66 while spanning between the opposing surfaces 63a and 64a.

[0057] Additionally, the second pressing portion 442 comes into contact with the +Z side surface (the surface opposite to the joint portion 65 side) of the extending portion 412 of the fixed elastic member 410. For example, when the elastic member 410 is pushed in the +Z direction by water flowing out from the joint portion 65, the second pressing portion 442 presses a part of the extending portion 412 so that the entire extending portion 412 does not deform in the +Z direction.

[0058] The extending portion 412 has a protruding portion 13 formed adjacent to the inside (the expandable portion 411 side) of the portion that comes into contact with the second pressing portion 442, and protruding in the +Z direction. The shape and size of the protruding portion 13 are the same as those in the above embodiment. A gap is provided between the protruding portion 13 and the second pressing portion 442, and this gap is the same as the gap between the protruding portion 13 and the pressing member 40 described with reference to FIG. 3.

[0059] As described above in detail regarding the embodiments, the flexible joint 1 according to the fifth embodiment of the present invention is a flexible joint 401 provided in a joint 65 of concrete structures 63, 64, and includes an expansion / contraction section 411 that expands and contracts the flexible joint 401, extension sections 412 extending from both ends of the expansion / contraction section 411, and an expansion / contraction member 410 having bent sections (mounting sections 413) bent from the ends of each extension section 412; and an expansion / contraction member 410 attached to opposing surfaces 63a, 64a of the concrete structures 63, 64, respectively. and a pressing member 440 attached to the extension portion 412, the pressing member 440 having a first pressing portion 441 that presses the bent portion (attaching portion 413) against the opposing surfaces 63a, 64a, and a second pressing portion 442 that intersects with the first pressing portion 441 and comes into contact with a part of the extension portion 412, the extension portion 412 having a protruding portion 13 formed at a position adjacent to the second pressing portion 442 to increase its thickness, the protruding portion 13 rising from the second pressing portion 442 side at a steeper angle than the protruding angle from the extension portion 411 side.

[0060] According to this configuration, the protrusions 13 that increase the thickness of the expandable member 410 are formed in locations where local strain is likely to occur in the expandable member 410 when the water pressure of water leaking from the joint 65 acts on the expandable member 410, or when the concrete structures 63, 64 are displaced and the flexible joint 401 follows the displacement. This increases the rigidity of the expandable member 410 in areas where local strain is likely to occur, thereby reducing the strain that occurs. In addition, the rise angle of the protrusions 13 from the second pressing portion 442 side is set to a steeper angle than the rise angle from the expandable portion 411 side. This allows the portion closer to the expandable portion 411 than the protrusions 13 to be smoothly bent and deformed, making it less likely that abrupt changes in bending will occur, resulting in local strain.

[0061] As shown in Figures 8(a) and 8(b), numerical analysis using the finite element method was used to calculate the strain that occurs in the telescopic member 510A where no protrusions are formed (Figure 8(a)), and the strain that occurs in the telescopic member 510 where protrusions 13 are formed (Figure 8(b)) when the telescopic members 510A, 510 are subjected to force in the Z-axis direction (upward in the figure). Note that the lighter the color in the figure, the greater the strain that occurs.

[0062] In both cases, the maximum strain occurs in the elastic members 510, 510A near the attachment portions 512, 512A, but the maximum strain of the elastic member 510A without a protrusion was 0.631 (FIG. 8(a)), while the maximum strain of the elastic member 510 with the protrusion 13 was 0.553. In this way, it was confirmed that by forming the protrusion 13 near the attachment portion 512, the maximum strain occurring in the elastic member 510 can be suppressed.

[0063] The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. As explained with reference to FIG. 3, the protrusion amount H of the protrusion 13 is approximately half the thickness t1 of the presser member 40, but this relationship is not limited to this. As shown in FIG. 6(a), different configurations of the presser member 240 have different thicknesses, and the relationship with the protrusion amount H also varies. On the other hand, it is preferable that the protrusion amount H of the protrusion 13 be smaller than the thickness of the presser member 40. This makes it easier for the protrusion 13 to lean against the presser member 40, and makes it easier to suppress local strain occurring in the extensible member 10.

[0064] Furthermore, although it has been explained that the gap G provided between the protrusion 13 and the pressing member 40 is approximately 0.15 times the protrusion amount H of the protrusion 13, the relationship between these can be any desired value. Although the problem of interference between the protrusion 13 and the pressing member 40 occurs, the gap G may be made smaller, or even eliminated altogether. Furthermore, the gap G may be made larger within a range that allows the protrusion 13 to lean against the pressing member 40.

[0065] Furthermore, the cross-sectional shape of protrusion 13 is not limited to the above-mentioned shape. For example, although the side surface of protrusion 13 on the side of stretchable portion 11 has been described as being arc-shaped in the cross section, it may be a side surface that can be represented as a straight line. That is, the cross-sectional shape of protrusion 13 may be trapezoidal, and the upper base of the trapezoid may be bulged or recessed in an arc shape.

[0066] Although the flexible joints described above have been applied to utility tunnels, they can also be applied to a variety of concrete structures, such as various water supply and treatment facilities, subways, tunnels, underground passages, and tunnel segments.

[0067] Furthermore, although the protective cloth 170 is provided on the flexible joint 101 of the second embodiment shown in Fig. 5, it can also be provided on flexible joints of other types. Even in this case, by passing the protective cloth between the protruding portion and the pressing member (or the second pressing portion), the protective cloth can be made less likely to come off.

[0068] Furthermore, although the material of the elastic member has been described as chloroprene rubber, it may be other rubber materials or may be appropriately selected from among elastic materials. [Explanation of symbols]

[0069] 1...flexible joint, 10...expandable member, 11...expandable portion, 12...mounting portion, 12a...bolt insertion hole, 13...protruding portion, 13a...rising surface, 13b...pointed end surface, 13c...arc connecting surface, 20...waterstop material, 30...anchor bolt, 31...nut, 40...pressure member, 40a...bolt insertion hole, 40b...end surface, 50...pressure area, 51...non-pressure area, 53...local strain generation portion, 60...concrete structure, 61...joint portion, 63, 64...concrete structure, 63a, 64a...opposing surface, 64b...orthogonal surface, 65...joint portion, 66...recess, 101...flexible joint, 110...expandable member, 111...expandable portion, 170...protective cloth, 170a...edge portion, 171...folding portion, 201...flexible joint, 210...expandable member, 211...expandable portion, 212...mounting portion, 214...projecting edge portion, 220...waterstop material, 240...pressing member, 240a...opening, 240b...mounting surface, 270...fixing member, 271...pressing arm, 272...intermediate plate-shaped portion, 301...flexible joint, 310...expandable member, 311...expandable portion, 312... Mounting portion, 340...pressing member, 341...flat plate portion, 342...groove-shaped portion, 342a...side plate portion, 401...flexible joint, 410...expandable member, 411...expandable portion, 412...extending portion, 413...mounting portion, 440...pressing member, 441...first pressing portion, 442...second pressing portion, θ1, θ2...rise angle, G...gap, H...projection amount, T...force

Claims

1. A flexible joint provided at a joint portion of a concrete structure, An elastic member having an elastic portion in the center that expands and contracts the flexible joint, the elastic portion being provided so as to straddle the joint portion; and a pressing member arranged on both sides of the joint portion and pressing the mounting portion set on the outside of the expansion and contraction portion to press the expansion and contraction member against the concrete structure, The elastic member has a protrusion formed at a position adjacent to the center of the attachment portion to increase the thickness thereof, The protruding portion has a rising angle from the mounting portion side that is steeper than the rising angle from the extension portion side. Flexible joints.

2. a surface of the protrusion on the mounting portion side that is perpendicular to the mounting portion and faces an end surface of the pressing member with a gap therebetween; 10. The flexible joint of claim 1.

3. a gap between the protruding portion and the pressing member is smaller than a protruding amount of the protruding portion; 3. The flexible joint of claim 2.

4. a protective cloth covering the elastic member; The edge of the protective cloth is passed between the surface of the protrusion on the attachment portion side and the end surface of the pressing member, and is sandwiched between the pressing member and the elastic member.

3. The flexible joint of claim 2.

5. A flexible joint provided at a joint portion of a concrete structure, an elastic member having an elastic section that expands and contracts the flexible joint, extension sections that extend from both ends of the elastic section, and bent sections that are bent from the ends of each of the extension sections; and pressing members attached to opposing surfaces of the concrete structure, the pressing member has a first pressing portion that presses the bent portion against the opposing surface, and a second pressing portion that intersects with the first pressing portion and comes into contact with a part of the extending portion, a protrusion that increases the thickness of the extension portion is formed at a position adjacent to the second pressing portion, The rising angle of the protruding portion from the second pressing portion side is steeper than the rising angle from the stretchable portion side. Flexible joints.

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