Flexible joint and method for installing flexible joint

Abstract

To provide a flexible joint that allows for easy installation of fire-resistant materials. [Solution] The flexible joint 20 comprises a joint frame 30 fixed to the ends of the structures 1 to be connected, a watertight material 40 provided between the joint frames 30, and an inner fire-resistant unit 60 provided inside the watertight material 40. The inner fire-resistant unit 60 has fire-resistant materials 61 and 62 and a fire-resistant material holder 63 that holds the fire-resistant materials 61 and 62, and the fire-resistant materials 61 and 62 are connected to the joint frame 30 via the fire-resistant material holder 63.

Description

Technical Field

[0001] The present invention relates to a flexible joint and a method for installing a flexible joint.

Background Art

[0002] As a joint for connecting various tunnel structures such as underpasses, underground shopping malls, and road tunnels, Patent Document 1 discloses a flexible joint having a rubber waterstop. A refractory is provided in this flexible joint to protect the waterstop from a fire occurring inside the structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The refractory described in Patent Document 1 is attached on-site using bolts, but there is a desire to reduce the burden of the attachment work of this refractory.

[0005] The present invention has been made paying attention to such problems, and an object thereof is to provide a flexible joint that can easily attach a refractory.

Means for Solving the Problems

[0006] To achieve the above object, the flexible joint of the present invention includes joint frames respectively fixed to ends of structures to be connected, a waterstop provided between the joint frames, and a first refractory unit provided inside the waterstop. The first refractory unit has a first refractory and a first refractory holder that holds the first refractory, and the first refractory is connected to the joint frame via the first refractory holder.

[0007] The first fire-resistant material holder may be provided on both sides of the first fire-resistant material, separated from each other, with the expansion and contraction portion of the first fire-resistant material in between.

[0008] The first fire-resistant unit is provided with a second fire-resistant unit located on the outside, the second fire-resistant unit comprising a second fire-resistant material and a second fire-resistant material holder that holds the second fire-resistant material, and a space may be provided between the first fire-resistant material and the second fire-resistant material, at least in part.

[0009] The first fire-resistant material holder is connected to a bracket detachably attached to the joint frame, and the second fire-resistant material holder may be connected to the joint frame.

[0010] Furthermore, in order to achieve the above objective, the method for installing a flexible joint of the present invention comprises a joint frame installation step of installing a joint frame at each end of the structures to be connected; a waterproofing material installation step of installing a waterproofing material between the joint frames; and a fire-resistant unit installation step of installing a fire-resistant unit, in which a fire-resistant material is held by a fire-resistant material holder, inside the waterproofing material, wherein the fire-resistant unit installation step includes a step of connecting the fire-resistant unit to the joint frame via the fire-resistant material holder.

[0011] The fire-resistant unit installed in the fire-resistant unit installation step is fitted with a reinforcing body to reinforce the fire-resistant unit, and the reinforcing body may be removed from the fire-resistant unit after the fire-resistant unit installation step. [Effects of the Invention]

[0012] According to the present invention, a flexible joint can be provided that allows for easy installation of fire-resistant materials. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view of a flexible joint according to Embodiment 1 of the present invention. [Figure 2] This is a cross-sectional view of the flexible joint cut along the cross-sectional line II-II in Figure 1. [Figure 3] This figure shows the outer fire-resistant unit of a flexible joint according to Embodiment 1 of the present invention, where (a) is a front view and (b) is a plan view as seen from arrow b in (a). [Figure 4] This figure shows the inner fire-resistant unit of a flexible joint according to Embodiment 1 of the present invention, where (a) is a front view and (b) is a plan view as seen from arrow b in (a). [Figure 5] This is a cross-sectional view showing the installation process of a flexible joint according to Embodiment 1 of the present invention in order of steps ((a) to (c)). [Figure 6] (a) is a cross-sectional view of the flexible joint cut along the cross-sectional line VIa-VIa in Figure 5(c), and (b) to (c) are cross-sectional views showing the installation process of the flexible joint, continuing from Figure 5(c). [Figure 7] (a) and (b) are cross-sectional views showing the installation process of the flexible joint, continuing from Figure 6(c), and (c) is a cross-sectional view of the flexible joint cut along the cross-sectional line VIIc-VIIc in Figure 7(b). [Figure 8] (a) and (b) are cross-sectional views showing the installation process of the flexible joint, continuing from Figure 7(b). [Figure 9] This is a front view showing the outer fire-resistant unit with width adjustment bolts attached. [Figure 10] This is a front view of a flexible joint according to Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0014] (Embodiment 1) Hereinafter, the flexible joint 20 according to Embodiment 1 of the present invention will be described with reference to the drawings. Note that the structure 1 shown in FIG. 1 is a circular underground tunnel constructed by the shield method. As shown in FIG. 1, the right direction in the drawing, which is the direction (axial direction) in which the tunnel as the structure 1 extends, is defined as the +Z direction, and the opposite direction is defined as the -Z direction, and these directions are referred to as appropriate. FIG. 1 shows a partial longitudinal section when cut along a plane parallel to the Z axis. The structure 1 is constructed by assembling segments 10, 10 such as steel segments, concrete segments, and ductile segments in a cylindrical shape.

[0015] The flexible joint 20 connects the segments 10, 10 provided at intervals in the Z-axis direction. The flexible joint 20 includes a pair of joint frames 30, 30 fixed to the opposing end portions of the segments 10, 10 with bolts not shown, a water stop material 40 provided between the pair of joint frames 30, 30, an outer fireproof unit 50 (second fireproof unit) and an inner fireproof unit 60 (first fireproof unit) disposed in a double layer inside the water stop material 40, brackets 70, 70 for attaching the inner fireproof unit 60 to the joint frames 30, 30, and a fireproof plate 90 provided on the inner fireproof unit 60. As shown in FIG. 1, the flexible joint 20 has a symmetric configuration. Therefore, hereinafter, for the components provided in pairs, the description of the configuration on the left side (-Z side) in FIG. 1 may be given, and the description of the configuration on the right side (+Z side) may be omitted. Note that the joint frame 30 is divided into a plurality of pieces (circumferentially divided pieces) in the circumferential direction of the tunnel cross section, similar to the segment 10. The joint frames 30 are connected in the circumferential direction to form an annular shape similar to the segment 10.

[0016] The joint frame 30 has a skin plate 31 curved with a curvature substantially equal to the outer surface of the segment 10, a first main girder 32 and a second main girder 33 erected from the inner surface of the skin plate 31, a vertical rib 34 connecting the first main girder 32 and the second main girder 33, and a mounting plate 35 for attaching the outer fireproof unit 50. Each component of the joint frame 30 is formed of, for example, steel material, and each member is connected by welding.

[0017] The first main girder 32 is welded to the -Z side end (the end on the segment 10 side) of the skin plate 31 in a manner such that its surface is orthogonal to the axial direction (Z direction) of the structure 1. The height (radial width) of the first main girder 32 is equal to the height of the segment 10.

[0018] The second main girder 33 is parallel to the first main girder 32 and is arranged at an interval in the Z-axis direction. The second main girder 33 is welded to the inner surface of the skin plate 31 in a manner such that its surface is orthogonal to the axial direction (Z direction) of the structure 1. The height of the second main girder 33 is set lower than the height of the first main girder 32. An attachment portion 41 of the water stop material 40 is fixed to the surface of the second main girder 33 facing the +Z side (the side where the other second main girder 33 is located) by attachment bolts 45.

[0019] The longitudinal ribs 34 are welded between the first main girder 32 and the second main girder 33 in a state orthogonal to these main girders. As shown in FIG. 2, a plurality of longitudinal ribs 34 are arranged at a predetermined interval in the circumferential direction C of the cross section of the structure 1.

[0020] As shown in FIG. 2, the attachment plates 35 are provided so as to project in the circumferential direction C from both surfaces of each of the longitudinal ribs 34. As shown in FIG. 1, the width of the attachment plate 35 in the Z-axis direction is narrower than the width direction (Z direction) of the longitudinal rib 34 and is provided at the center in the width direction of the longitudinal rib 34. Further, the attachment plate 35 and the longitudinal rib 34 are welded in a state where their inner (lower side in FIG. 2) ends are flush. As shown in FIG. 1, nuts 36 are welded to the attachment plate 35, and bolt holes 35a for passing stud bolts 37 screwed into the nuts 36 are formed.

[0021] The waterproofing material 40 is made of an elastic material of a predetermined hardness, such as rubber or synthetic resin. The waterproofing material 40 has mounting portions 41 at both ends that are bent inward, and a V-shaped bent portion 42 in the center in the width direction (Z-axis direction). This bent portion 42 is provided to protrude inward and functions as an expandable portion that expands and contracts when the flexible joint 20 expands and contracts or when shear force is applied and displacement occurs. The mounting portions 41 at both ends of the waterproofing material 40 are fastened to the second main girders 33 of the left and right joint frames 30 in Figure 1 with mounting bolts 45, thereby connecting the pair of joint frames 30 while maintaining the watertightness inside the flexible joint 20.

[0022] The outer fire-resistant unit 50 includes a fire-resistant material 51 (second fire-resistant material) having fire-resistant properties, and fire-resistant material holders 52, 52 (second fire-resistant material holders) for attaching the outer fire-resistant unit 50 to the joint frame 30 while holding the fire-resistant material 51. The outer fire-resistant unit 50, like the joint frame 30, is divided into multiple pieces (circumferential dividing pieces) in the circumferential direction C of the structure 1. In Figure 2, two outer fire-resistant units 50 connected in the circumferential direction C are shown along their entire length, and the outer fire-resistant unit 50 is divided at the boundary L1.

[0023] As shown in Figure 3, the fire-resistant material 51 is formed by wrapping an inorganic fiber 51a with thermal insulation properties with a protective sheet 51b with thermal insulation properties. The fire-resistant material 51 has mounting portions 53, 53 at both ends that are bent inward, and a bent portion 54 formed in a U shape in the center in the width direction (Z direction). This bent portion 54 protrudes inward and functions as an expandable portion that expands and contracts when the flexible joint 20 expands and contracts or when shear force is applied and displacement occurs.

[0024] The inorganic fiber 51a is preferably made of a material selected from the group consisting of ceramic fiber, rock wool, and glass wool. In this embodiment, two layers of ceramic fiber with a thickness of 25 mm are used.

[0025] The protective sheet 51b is preferably made of a non-combustible sheet consisting of glass cloth or glass cloth coated with silicone, which has heat resistance and is easily deformable. The inorganic fiber 51a is shaped by wrapping it with such a protective sheet 51b, and its water repellency is also improved.

[0026] As shown in Figure 1, the fire-resistant material holders 52 are arranged side by side in the Z-axis direction and hold the -Z side portion and the +Z side portion of the fire-resistant material 51. The fire-resistant material holders 52, 52 have symmetrical shapes. Therefore, the fire-resistant material holder 52 located on the -Z side will be described below, and the description of the other fire-resistant material holder 52 will be omitted. As shown in Figure 3, the fire-resistant material holder 52 has a mounting plate 55 that contacts the fire-resistant material 51 from the radially outer side, and a rectangular extension plate 56 welded to the -Z side end of the mounting plate 55.

[0027] As shown in Figures 2 and 3, the mounting plate 55 is formed from a rectangular plate whose longitudinal direction is in the circumferential direction C of the structure 1. As shown in Figure 2, the mounting plate 55 is curved with a predetermined curvature according to the circular cross-sectional shape of the structure 1. As shown in Figures 3(a) and 3(b), three nuts 57 are welded to the mounting plate 55 in the circumferential direction C. The stud bolts 58 are screwed into these nuts 57 and erected on the mounting plate 55. In addition, as shown in Figure 1, mounting holes 51c are formed in the fire-resistant material 51 at positions corresponding to the stud bolts 58. As shown in Figure 1, the stud bolts 58 are passed through these mounting holes 51c, and nuts 59 are tightened with washers 81 in between. In this way, the fire-resistant material 51 is attached to the mounting plate 55. Furthermore, as shown in Figures 3(a) and 3(b), the mounting plate 55 has mounting holes 55a for passing the stud bolts 37 (Figure 1). Mounting holes 55a are formed one at each end of the mounting plate 55 in the circumferential direction C. The positions where these mounting holes 55a are formed are closer to the ends than the mounting positions of the stud bolts 58 and the mounting positions of the reinforcing plate 85, which will be described later. This makes it easy to see the mounting holes 55a by peeling back the fire-resistant material 51 that was covering the mounting holes 55a from the end, thus facilitating work on the mounting holes 55a. As shown in Figure 1, nuts 38 are tightened onto the stud bolts 37 that are passed through the mounting holes 55a.

[0028] As shown in Figure 1, the extension plate 56 is mounted perpendicular to the mounting plate 55 and parallel to the first main girder 32. In this embodiment, as shown in Figure 2, three extension plates 56 are provided at predetermined intervals in the circumferential direction C of the cross-section of the structure 1. As shown in Figures 3(a) and 3(b), nuts 71 are welded to the surface of the extension plate 56 facing the fire-resistant material 51. Stud bolts 72 are screwed into these nuts 71 and erected on the extension plate 56. Mounting holes 51d are formed in the fire-resistant material 51 at positions corresponding to the stud bolts 72. As shown in Figure 1, the stud bolts 72 are passed through these mounting holes 51d, and nuts 73 are tightened with washers 82 in between. In this way, the fire-resistant material 51 is attached to the extension plate 56. Mounting holes 56a for passing bolts 74 are also formed in the extension plate 56. The bolt 74 is passed through the mounting hole 56a and fastened to a female thread (not shown) formed in the first main girder 32. In this way, the fire-resistant material holder 52, which holds the fire-resistant material 51, is connected to the joint frame 30 by fastening components such as stud bolts 37, nuts 38, and bolts 74.

[0029] As shown in Figure 3(a), the fire-resistant material holders 52, 52 that hold the fire-resistant material 51 are provided separately on both sides of the fire-resistant material 51, flanking the bent portion 54 of the fire-resistant material 51. The fire-resistant material 51 is easily deformed, and if the fire-resistant material 51 is only held on both sides by the fire-resistant material holders 52, 52, the outer fire-resistant unit 50 will easily deform. Therefore, the outer fire-resistant unit 50 is provided with a reinforcing plate 85 that connects the separated fire-resistant material holders 52, 52. The reinforcing plate 85 maintains the shape of the outer fire-resistant unit 50 before it is attached to the joint frames 30, 30. After the outer fire-resistant unit 50 is installed, the reinforcing plate 85 is removed from the outer fire-resistant unit 50.

[0030] The reinforcing plates 85 are provided at predetermined intervals in the circumferential direction C of the structure 1. In this embodiment, three reinforcing plates 85 are provided on one outer fire-resistant unit 50 in accordance with the arrangement of the extension plates 56. As shown in Figure 3(a), the reinforcing plate 85 has mounting portions 85a formed by bending both ends of a plate that is long in one direction at a right angle, and has a groove-shaped form. Stud bolts 72 erected on the extension plate 56 are passed through the mounting portions 85a, and nuts 78 are tightened. In this way, the reinforcing plate 85 connects the fire-resistant material holders 52, 52 which are separated via the stud bolts 72, 72 on the left and right sides in the figure.

[0031] As shown in Figure 1, the brackets 70, 70 are attached to the first main girders 32, 32 of the pair of joint frames 30, 30, respectively. Since these brackets 70, 70 have a symmetrical configuration, the left bracket 70 in Figure 1 will be described, and the description of the right bracket 70 will be omitted. As shown in Figure 1, the bracket 70 has an L-shaped cross-section when cut by a plane perpendicular to the circumferential direction C (Figure 2). The bracket 70 has a first plate portion 75 parallel to the first main girder 32 and a second plate portion 76 attached to the first plate portion 75. As shown in Figure 2, the second plate portion 76 is welded to the center of the edge of the first plate portion 75, rising vertically from the first plate portion 75. The bracket 70 is attached to the first main girder 32 by fastening bolts 77, which are passed through the first plate portion 75, to female threads (not shown) formed in the first main girder 32. The second plate portion 76 protrudes toward the second plate portion 76 of the other bracket 70 (towards the inside of the flexible joint 20). As shown in Figure 2, the bracket 70 is provided so as to straddle the boundary L1 such that the boundary L1 of the adjacent inner fire-resistant unit 60 coincides with its center. The second plate portion 76 has two bolt insertion holes 76a (Figure 1) formed on both sides of the boundary L1. Note that in the circumferential direction C of the cross-section of the structure 1, the boundary of the outer fire-resistant unit 50 and the boundary of the inner fire-resistant unit 60 are both the same boundary L1.

[0032] As shown in Figure 1, the inner fire-resistant unit 60 has fire-resistant materials 61 and 62 (sometimes referred to as the first fire-resistant material together) and fire-resistant material holders 63, 63 (first fire-resistant material holders) attached to brackets 70, 70 while holding the fire-resistant materials 61 and 62. Similar to the outer fire-resistant unit 50, the inner fire-resistant unit 60 is divided into multiple pieces (circumferential dividing pieces) in the circumferential direction of the cross-section of the structure 1. In Figure 2, two outer fire-resistant units 50 connected in the circumferential direction C are shown along their entire length, and the inner fire-resistant unit 60 is divided at the boundary L1. A gap (fire-resistant space 80) is provided between the inner fire-resistant unit 60 and the outer fire-resistant unit 50. In addition, notches 61c are formed on both sides of the inner fire-resistant unit 60 for installing the fire-resistant boards 97 of the adjacent segment 10.

[0033] As shown in Figure 4, the fire-resistant material 61 is formed by wrapping an insulating inorganic fiber 61a with an insulating protective sheet 61b. The inorganic fiber 61a and the protective sheet 61b can be made of the same materials as those used for the fire-resistant material 51.

[0034] The fire-resistant material 62 is laminated on the outside of the fire-resistant material 61, and its planar dimensions are approximately the same as those of the fire-resistant material 61. The fire-resistant material 62 is formed from, for example, a material having high thermal insulation properties. For example, a molded body made of ceramic powder reinforced with inorganic fibers can be used.

[0035] The fire-resistant materials 61 and 62 are overlapped and have a bent portion 64 that is folded in the center in the width direction (Z direction) to have a U-shaped cross-section. This bent portion 64 protrudes outward and functions as an expandable portion that expands and contracts when the flexible joint 20 expands and contracts or when shear force is applied and displacement occurs. In addition, as shown in Figure 1, the fire-resistant materials 61 and 62 cover a portion of the segment 10 adjacent to the flexible joint 20. This allows the entire interior of the flexible joint 20 to be covered with the fire-resistant materials 61 and 62, thereby blocking heat from reaching the waterproofing material 40.

[0036] As shown in Figure 4, the fire-resistant material holders 63, 63 are arranged side by side in the Z-axis direction and hold the -Z-side and +Z-side portions of the fire-resistant material 61 and fire-resistant material 62 via fastening components such as bolts, nuts, and washers. The fire-resistant material holders 63, 63 have symmetrical shapes. Therefore, the fire-resistant material holder 63 located on the -Z side will be described below, and the description of the other fire-resistant material holder 63 will be omitted. As shown in Figures 4(a) and 4(b), the fire-resistant material holder 63 consists of a rectangular plate with its longitudinal direction in the circumferential direction C of the structure 1. As shown in Figure 2, the fire-resistant material holder 63 is curved with a predetermined curvature according to the circular cross-sectional shape of the structure 1. As shown in Figure 4(b), a total of six nuts 65 are welded to the fire-resistant material holder 63 in a grid pattern with three rows in the circumferential direction C and two rows in the axial direction Z. The stud bolt 66 is screwed into the nut 65 and erected on the fire-resistant material holder 63. Mounting holes are formed in the fire-resistant materials 61 and 62 at positions corresponding to the stud bolt 66. As shown in Figure 4(a), the stud bolt 66 is passed through these mounting holes, and a clawed washer 96 is attached to the stud bolt 66. This attaches the fire-resistant materials 61 and 62 to the fire-resistant material holder 63. The clawed washer 96 has multiple claws facing the central hole, and these claws catch on the surface of the stud bolt 66, allowing the fire-resistant materials 61 and 62 to be temporarily fastened to the stud bolt 66.

[0037] Furthermore, as shown in Figures 4(a) and 4(b), the fire-resistant material holder 63 has mounting holes 63a for passing bolts 68 (Figure 1) through. Two mounting holes 63a are formed near each end of the mounting plate 55 in the circumferential direction C. The positions where these mounting holes 63a are formed are closer to the ends than the positions of the stud bolts 66 and the reinforcing plate 86, which will be described later. This makes it easy to see the mounting holes 63a by peeling back the fire-resistant material 61 and fire-resistant material 62 that were covering the mounting holes 63a from the ends, thus facilitating work on the mounting holes 63a. As shown in Figure 1, nuts 69 are tightened on the bolts 68 that are passed through the mounting holes 63a. In this way, the fire-resistant material holder 63, which holds the fire-resistant material 61 and fire-resistant material 62, is connected to the bracket 70 attached to the joint frame 30 by fasteners consisting of bolts 68 and nuts 69. In other words, the fire-resistant material 61 and the fire-resistant material 62 are connected to the joint frame 30 via the fire-resistant material holder 63.

[0038] As shown in Figure 4(a), the fire-resistant material holders 63 that hold the fire-resistant materials 61 and 62 are provided on both sides of the fire-resistant materials 61 and 62, separated from each other, with the bent portion 64 in between. The fire-resistant materials 61 and 62 are easily deformed, and if the inner fire-resistant unit 60 is only held on both sides of the fire-resistant materials 61 and 62 by the fire-resistant material holders 63, it will easily deform. Therefore, the inner fire-resistant unit 60 is provided with a reinforcing plate 86 that connects the separated fire-resistant material holders 63. The reinforcing plate 86 maintains the shape of the inner fire-resistant unit 60 before it is attached to the joint frames 30, 30. After the inner fire-resistant unit 60 is installed, the reinforcing plate 86 is removed from the inner fire-resistant unit 60.

[0039] The reinforcing plates 86 are provided at predetermined intervals in the circumferential direction C of the structure 1. In this embodiment, three reinforcing plates 86 are provided in one inner fire-resistant unit 60 in accordance with the arrangement of the stud bolts 66. The reinforcing plates 86 are long in the axial direction (Z direction) of the structure 1. Stud bolts 66 erected on the fire-resistant material holders 63 are passed through the reinforcing plates 86 and nuts 79 are tightened. In this way, the reinforcing plates 86 connect the fire-resistant material holders 63, 63 which are separated via the stud bolts 66, 66 on the left and right sides in the figure.

[0040] As shown in Figure 1, the fire-resistant plate 90 is attached to the inner fire-resistant unit 60 from which the reinforcing plate 86 has been removed. The fire-resistant plate 90 is made of stainless steel and functions as a decorative plate that covers the inner fire-resistant unit 60. Stud bolts 66 erected on the fire-resistant material holder 63 are passed through the fire-resistant plate 90, and nuts 67 are tightened with washers 83 in between.

[0041] Next, the process for installing the flexible joint 20 will be described. First, as shown in Figure 5(a), the joint frame 30 is attached to each end of the structures 1 to be connected using bolts (not shown), and then the waterproofing material 40 is installed between the joint frames 30. The waterproofing material 40 is installed via mounting bolts 45.

[0042] Next, the stud bolt 37 is screwed into the nut 36 welded to the joint frame 30.

[0043] Next, as shown in Figure 5(b), a thrust receiving member 98 is installed between the left and right joint frames 30. This allows the thrust acting during excavation to be received by the thrust receiving member 98, maintaining the distance between the two joint frames 30 and preserving the shape of the watertight material 40.

[0044] After the excavation is complete, the thrust support member 98 is removed, and then, as shown in Figure 5(c), the stud bolts 37 are passed through the mounting plate 55 of the pre-assembled outer fire-resistant unit 50 and tightened with nuts 38. At this time, as shown in Figure 6(a), by peeling back the end of the fire-resistant material 51, the mounting holes 55a (Figure 3(a)) formed in the mounting plate 55 become visible, and a workspace is created for tightening the nuts 38. The nuts 38 can be tightened by hand or with a tool, for example, using a long socket 91.

[0045] Next, as shown in Figure 6(b), bolts 74 are passed through the extension plate 56 and fastened to female threads (not shown) formed on the first main girder 32. This fixes the outer fire-resistant unit 50 to the joint frame 30.

[0046] Next, loosen the nuts 78 that were fastened to the stud bolts 72, and remove the reinforcing plate 85 from the outer fire-resistant unit 50 as shown in Figures 6(b) to 6(c).

[0047] Next, as shown in Figure 7(a), the bracket 70 is fixed to the first main girder 32 by passing a bolt 77 through the bracket 70 and fastening it to a female thread (not shown) formed on the first main girder 32. In this way, the bracket 70 is connected to the first main girder 32 by the bolt 77, and is configured to be detachably attached to the first main girder 32.

[0048] Next, as shown in Figure 7(b), a bolt 68 is passed through the fire-resistant material holder 63 of the pre-assembled inner fire-resistant unit 60, and a nut 69 is tightened. At this time, as shown in Figure 7(c), by peeling back the ends of the fire-resistant materials 61 and 62, the mounting hole 63a formed in the fire-resistant material holder 63 becomes visible, and a workspace is created for tightening the nut 69. The nut 69 can be tightened by hand or with a tool, for example, using a long socket 91. This fixes the inner fire-resistant unit 60 to the bracket 70.

[0049] Next, loosen the nut 79 and remove the reinforcing plate 86 from the inner fire-resistant unit 60 as shown in Figures 7(b) to 8(a). At this time, the fire-resistant materials 61 and 62 will not come off the inner fire-resistant unit 60 because they are temporarily fixed by the clawed washers 96.

[0050] Finally, as shown in Figure 8(b), nuts 67 are tightened onto stud bolts 66 that pass through the fireproof plate 90, and the fireproof plate 90 is attached to the inner fireproof unit 60. With these steps, the installation of the flexible joint 20 is completed. The reinforcing plate 85 removed from the outer fireproof unit 50 and the reinforcing plate 86 removed from the inner fireproof unit 60 can be reused when installing another fireproof unit.

[0051] This invention is not limited to the above embodiments, and various modifications and applications are possible.

[0052] In the above embodiment, a reinforcing plate 85 (reinforcement body) was attached to maintain the shape of the outer fire-resistant unit 50, and its length in the width direction could not be changed. However, as shown in Figure 9, for example, a width adjustment device 95 that can adjust the width (length in the Z direction) of the outer fire-resistant unit 50 may be attached. This width adjustment device 95 has suspension plates 93, 93 through which stud bolts 72 erected on the extension plate 56 are passed and fixed with nuts 78, an adjustment bolt 92 that is passed through insertion holes (not shown) formed in the suspension plates 93, 93 and has male threads cut at both ends, and a pair of nuts 94, 94 that are screwed onto the male threads of the adjustment bolt 92 and are provided in a position to sandwich the suspension plates 93. By rotating the nuts 94 and changing the position of the suspension plates 93 relative to the adjustment bolt 92, the distance between the suspension plates 93, 93 can be changed. This makes it possible to adjust the width of the outer fire-resistant unit 50 to match the distance of the joint frame 30, and improves the ease of installation of the outer fire-resistant unit 50. Such width adjustment devices 95 may be provided not only on the outer fire-resistant unit 50 but also on the inner fire-resistant unit 60.

[0053] Furthermore, the shape of the fire-resistant material holders 52 and 63 is arbitrary, as long as they can be connected to the joint frames 30, 30 while holding the fire-resistant material. For example, the fire-resistant material holder may be configured to hold the entire fire-resistant material, and may have an expandable portion that can accommodate the expansion and contraction of the flexible joint 20.

[0054] Furthermore, although Figure 1 shows the fire-resistant material 51 of the outer fire-resistant unit 50 and the fire-resistant material 62 of the inner fire-resistant unit 60 in contact in a portion (the central part), it is also possible to configure them so that they are separated at all points without any contact, thereby securing a fire-resistant space 80.

[0055] Furthermore, although it has been explained that the connection between the fire-resistant material holder 52 and the joint frame 30, and the connection between the fire-resistant material holder 63 and the bracket 70 are made using bolts and nuts, other connection methods may also be used. For example, a joint may be used in which a male part is attached to one of the objects to be connected and a female part is attached to the other, and the male and female parts are fitted together to secure them.

[0056] Furthermore, while the attachment of the fire-resistant material 51 to the fire-resistant material holder 52, and the attachment of the fire-resistant materials 61 and 62 to the fire-resistant material holder 63 were described using bolts and nuts, the method of attachment is arbitrary as long as the fire-resistant material is held in place by these holders. For example, the fire-resistant material may be attached using double-sided tape or hook-and-loop fasteners.

[0057] Furthermore, although we have described the case in which the bent portion 54 of the fire-resistant material 51 protrudes inward and the bent portions 64 of the fire-resistant materials 61 and 62 protrude outward, the direction of protrusion of these bent portions 54 and 64 is arbitrary. For example, they may protrude in the same direction either outward or inward. This makes it possible to secure a wider fire-resistant space 80.

[0058] Furthermore, the above embodiment describes a case where the height (radial thickness) of the segment 10 is large enough to provide a fire-resistant space 80 between the fire-resistant material 51 of the outer fire-resistant unit 50 and the fire-resistant material 62 of the inner fire-resistant unit 60. However, if the height of the segment 10 is small and a sufficient fire-resistant space 80 (Figure 1) cannot be secured, the fire-resistant materials may be overlapped as shown in Figure 10, so that the fire-resistant space 80 is not provided, or the fire-resistant space 80 is made smaller than in the above embodiment. Next, an embodiment 2 in which no fire-resistant space 80 is provided will be described with reference to Figure 10.

[0059] (Embodiment 2) The flexible joint 120 shown in Figure 10 differs from the flexible joint of Embodiment 1, which has two fire-resistant units, in that it has only one fire-resistant unit 150. On the other hand, since there are many components in common with the above embodiment, the same reference numerals are used for the common components, and the explanation of the common components is omitted.

[0060] A pair of joint frames 130, fixed to the opposing ends of segments 10, 10 with bolts 110, have a first main girder 132 and a second main girder 133 of equal height. A bracket 70 is attached to the side of the first main girder 132. A fire-resistant material holder 63, which holds fire-resistant materials 161, 162, 163, and 164, is connected to this bracket 70 via fasteners consisting of bolts 68 and nuts 69. The fire-resistant materials 161, 162, 163, and 164 are connected to the joint frame 130 via the fire-resistant material holder 63.

[0061] The fire-resistant unit 150 has the same basic structure as the inner fire-resistant unit 60 shown in Figure 1, but differs in the number of layers of fire-resistant material it holds. The fire-resistant unit 150 has four layers of fire-resistant material 161, 162, 163, and 164 (all of these fire-resistant materials may be referred to as the first fire-resistant material), and a fire-resistant material holder 63 (first fire-resistant material holder) that is attached to the bracket 70 while holding the fire-resistant materials 161, 162, 163, and 164.

[0062] The fire-resistant material 161 is the innermost fire-resistant material, and, similar to the fire-resistant material 61 shown in Figure 4, is formed by insulating inorganic fibers being wrapped in an insulating protective sheet.

[0063] The refractory materials 162 and 163 are laminated on the outside of the refractory material 161 and, similar to the refractory material 62 shown in Figure 1, are formed from a molded body of ceramic powder reinforced with, for example, inorganic fibers.

[0064] The fire-resistant material 164 is laminated on the outside of the fire-resistant materials 162 and 163, and, similar to the fire-resistant material 51 shown in Figure 3, is formed by insulating inorganic fibers being wrapped in an insulating protective sheet.

[0065] The fire-resistant materials 161, 162, and 163 have similar planar dimensions and cover a portion of the segment 10 adjacent to the flexible joint 120. This allows the entire interior of the flexible joint 120 to be covered with the fire-resistant materials 161, 162, and 163, thereby blocking heat from reaching the waterproofing material 40.

[0066] In each embodiment, the number of layers of fire-resistant material in the fire-resistant unit is not limited; fewer or more layers of fire-resistant material may be used. The number of layers of fire-resistant material can be adjusted as appropriate depending on the situation in which the flexible joint is installed. Furthermore, the materials of the fire-resistant material described above are merely examples, and any materials with heat-resistant properties can be appropriately selected.

[0067] As described in detail above regarding the embodiments, the flexible joints 20, 120 according to the present invention comprises joint frames 30, 130 fixed to the ends of the structures 1 to be connected, a watertight material 40 provided between the joint frames 30, 130, and a first fire-resistant unit (inner fire-resistant unit 60, fire-resistant unit 150) provided inside the watertight material 40. The first fire-resistant unit (inner fire-resistant unit 60, fire-resistant unit 150) comprises first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164) and a first fire-resistant material holder (fire-resistant material holder 63) that holds the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164), and the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164) is connected to the joint frames 30, 130 via the first fire-resistant material holder (fire-resistant material holder 63).

[0068] With this configuration, the first fire-resistant material holder (fire-resistant material holder 63), which holds the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164), is connected to the joint frame 30, 130. Therefore, it is not necessary to directly connect the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164) to the joint frame 30, 130 with bolts or the like. As a result, it is not necessary to bolt the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164) to the joint frame 30, 130 at the construction site, which reduces the burden of work at the site. Furthermore, since the first fire-resistant materials (fire-resistant materials 61, 62, and fire-resistant materials 161, 162, 163, and 164) are held by the first fire-resistant material holder (fire-resistant material holder 63), each component can be handled on-site as a single first fire-resistant unit (inner fire-resistant unit 60, fire-resistant unit 150), thereby reducing the workload on-site.

[0069] Furthermore, the first fire-resistant material holder (fire-resistant material holder 63) is provided on both sides of the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164) in a manner that separates it from the others, sandwiching the expandable portion (bent portion 64) of the first fire-resistant material (fire-resistant material 61, 62, fire-resistant material 161, 162, 163, 164).

[0070] With this configuration, the first fire-resistant material holder (fire-resistant material holder 63) does not obstruct the expansion and contraction movement of the first fire-resistant materials (fire-resistant materials 61, 62, and fire-resistant materials 161, 162, 163, 164), and the structure of the first fire-resistant material holder (fire-resistant material holder 63) can be simplified. Furthermore, since the first fire-resistant material holder (fire-resistant material holder 63) only needs to be provided on both sides, the weight of the flexible joint 20 can be reduced.

[0071] Furthermore, the flexible joint 20 includes a second fire-resistant unit (outer fire-resistant unit 50) provided on the outside of the first fire-resistant unit (inner fire-resistant unit 60), and the second fire-resistant unit (outer fire-resistant unit 50) has a second fire-resistant material (fire-resistant material 51) and a second fire-resistant material holder (fire-resistant material holder 52) that holds the second fire-resistant material (fire-resistant material 51), and at least a portion of the space is secured between the first fire-resistant material (fire-resistant materials 61, 62) and the second fire-resistant material (fire-resistant material 51).

[0072] With this configuration, the heat to the waterproofing material 40 can be blocked by the two layers of fire-resistant material, the first fire-resistant material (fire-resistant materials 61, 62) and the second fire-resistant material (fire-resistant material 51), and the fire-resistant space between them. This prevents the waterproofing material 40 from burning. Furthermore, in the event of a fire, repairs and replacements can be carried out only on the necessary side. In addition, by using multiple layers of fire-resistant material, each fire-resistant material can be made thinner, making processing and installation easier.

[0073] Furthermore, the first fire-resistant material holder (fire-resistant material holder 63) is connected to a bracket 70 that is detachably attached to the joint frame 30, and the second fire-resistant material holder (fire-resistant material holder 52) is connected to the joint frame 30.

[0074] With this configuration, even when installing two fire-resistant units (an outer fire-resistant unit 50 and an inner fire-resistant unit 60), they can be connected to the joint frame 30 via the fire-resistant material holders 52 and 63, eliminating the need to directly connect the fire-resistant material to the joint frame 30 with bolts or the like. This reduces the burden of on-site installation work for the fire-resistant material.

[0075] Furthermore, the method for installing the flexible joint 20 according to the present invention comprises a joint frame installation step of installing joint frames 30 at each end of the structures 1 to be connected, a water-sealing material installation step of installing water-sealing material 40 between the joint frames 30, and a fire-resistant unit installation step of installing a fire-resistant unit (inner fire-resistant unit 60) in which fire-resistant materials 61 and 62 are held by a fire-resistant material holder 63 inside the water-sealing material 40. The fire-resistant unit installation step includes a step of connecting the fire-resistant unit (inner fire-resistant unit 60) to the joint frame 30 via the fire-resistant material holder 63.

[0076] With this configuration, since the fire-resistant material holder 63 that holds the fire-resistant materials 61 and 62 is connected to the joint frame 30, there is no need to directly connect the fire-resistant materials 61 and 62 to the joint frame 30 with bolts or the like. Therefore, there is no need to bolt the fire-resistant materials 61 and 62 to the joint frame 30 on site, which reduces the burden of work on site. In addition, since the fire-resistant materials 61 and 62 are held by the fire-resistant material holder 63, the individual components can be handled on site as a fire-resistant unit (inner fire-resistant unit 60), which further reduces the burden of work on site.

[0077] Furthermore, the fire-resistant unit (inner fire-resistant unit 60) installed during the fire-resistant unit installation process is fitted with a reinforcing body (reinforcing plate 86) to reinforce the fire-resistant unit (inner fire-resistant unit 60), and after the fire-resistant unit installation process, the reinforcing body (reinforcing plate 86) is removed from the fire-resistant unit (inner fire-resistant unit 60).

[0078] With this configuration, the reinforcing body (reinforcing plate 86) makes the fire-resistant unit (inner fire-resistant unit 60) less prone to deformation and stronger, thus making it easier to handle during work. Furthermore, the reinforcing body (reinforcing plate 86) can be reused in another fire-resistant unit (inner fire-resistant unit 60) after removal, making it economical. [Explanation of Symbols]

[0079] 1...Structure, 10...Segment, 20...Flexible joint, 30...Joint frame, 31...Skin plate, 32...First main girder, 33...Second main girder, 34...Longitudinal rib, 35...Mounting plate, 35a...Bolt hole, 36,38,57,59,65,67,69,71,73,78,79,94...Nut, 37,58,66,72...Stud bolt, 40...Waterproofing material, 41...Mounting part, 42...Bend 45... Mounting bolt, 50... Outer fire-resistant unit, 51... Fire-resistant material, 51a... Inorganic fiber, 51b... Protective sheet, 51c, 51d... Mounting hole, 52... Fire-resistant material holder, 53... Mounting part, 54... Bent part, 55... Mounting plate, 55a... Mounting hole, 56... Extension plate, 56a... Mounting hole, 60... Inner fire-resistant unit, 61... Fire-resistant material, 61a... Inorganic fiber, 61b …protective sheet, 61c…notch, 62…fire-resistant material, 63…fire-resistant material holder, 63a…mounting hole, 64…bend, 68…bolt, 70…bracket, 74…bolt, 75…first plate section, 76…second plate section, 76a…bolt insertion hole, 77…bolt, 80…fire-resistant space, 81,82,83…washer, 85,86…reinforcement plate, 85a…mounting section, 90…fire-resistant plate 91...Long socket, 92...Adjustment bolt, 93...Suspension plate, 95...Width adjuster, 96...Claw washer, 97...Fireproof board, 98...Thrust support member, 110...Bolt, 120...Flexible joint, 130...Joint frame, 132...First main girder, 133...Second main girder, 150...Fireproof unit, 161,162,163,164...Fireproof material, C...Circumferential direction, L1...Boundary, Z...Axial direction

Claims

1. A joint frame fixed to each end of the connecting structures, A water-stopping material provided between the aforementioned joint frames, The watertight material comprises a first fire-resistant unit provided inside the aforementioned watertight material, The first fire-resistant unit comprises a first fire-resistant material and a first fire-resistant material holder that holds the first fire-resistant material. The first fire-resistant material is connected to the joint frame via the first fire-resistant material holder. Flexible joint.

2. The first fire-resistant material holder is provided on both sides of the first fire-resistant material, separated from each other, with the expansion and contraction portion of the first fire-resistant material in between. The flexible joint according to claim 1.

3. The first fire-resistant unit is provided with a second fire-resistant unit located on the outside of it. The second fire-resistant unit comprises a second fire-resistant material and a second fire-resistant material holder that holds the second fire-resistant material. A space is provided between the first fire-resistant material and the second fire-resistant material, at least in part. The flexible joint according to claim 1.

4. The first fire-resistant material holder is connected to a bracket that is detachably attached to the joint frame, The second fire-resistant material holder is connected to the joint frame. The flexible joint according to claim 3.

5. The process involves installing joint frames at each end of the structures to be connected, A waterproofing material installation step involves installing a waterproofing material between the aforementioned joint frames, The process includes a fire-resistant unit installation step, in which a fire-resistant unit, having a fire-resistant material held in a fire-resistant material holder, is installed inside the water-stopping material, The fire-resistant unit installation step includes the step of connecting the fire-resistant unit to the joint frame via the fire-resistant material holder. Method for installing flexible joints.

6. The fire-resistant unit installed in the aforementioned fire-resistant unit installation process is fitted with a reinforcing body to reinforce the fire-resistant unit. After the fire-resistant unit installation process, the reinforcing body is removed from the fire-resistant unit. The method for installing the flexible joint according to claim 5.

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