Tunnel waterproofing sheet deployment assist device and waterproofing sheet deployment method

Abstract

To improve the work efficiency of laying waterproof sheets on the inner surface of tunnels. [Solution] A waterproof sheet tensioning assist device 10 is installed inside the tunnel. The waterproof sheet tensioning assist device 10 includes an arch-shaped guide frame 12 that runs along the circumferential direction of the inner surface 3a of the tunnel, a support base 30 that is retractable into and out of the guide frame 12, and an operating mechanism 40 that operates the support base 30 between a storage position where it is housed within the guide frame 12 and a protruding position where it protrudes from the guide frame 12 and can receive the winding roll 5A of the waterproof sheet 5.

Description

Technical Field

[0001] The present invention relates to an apparatus for assisting the work of stretching a waterproof sheet for a tunnel and a method of stretching a waterproof sheet.

Background Art

[0002] Generally, in mountain tunnels such as NATM (New Austrian tunneling Method) tunnels, a waterproof sheet is stretched on the inner surface of the primary lining (see Patent Document 1, etc.). One waterproof sheet usually has a width of about 2 m. The waterproof sheet is stretched in the circumferential direction of the tunnel with the width direction facing the tunnel axis direction and is fixed to the inner surface of the primary lining through fixing means such as an electromagnetic induction welding disk. Further, the opposing edges of the waterproof sheets adjacent in the tunnel axis direction are joined by welding.

[0003] In recent years, in order to prevent poor joining between adjacent waterproof sheets at the construction site, for example, 2 to 4 waterproof sheets are connected in advance at the factory to make a wide-width waterproof sheet of 4 to 8 m, and the wide-width waterproof sheet is carried into the tunnel construction site and stretched, which has become the mainstream.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When laying this type of waterproof sheet, scaffolding is erected inside the tunnel under construction. Workers climb onto this scaffolding and lay the sheet manually. Specifically, the sheet is unrolled by rolling a roll of waterproof sheeting along the inner surface of the tunnel (the inner surface of the primary lining) from the top of the tunnel towards the bottom. The unrolled sheet is then pushed up and pressed against the inner surface of the tunnel, and secured to the tunnel surface with fixing devices. However, since the waterproof sheeting weighs several tens of kilograms, the laying process is a difficult task and requires multiple people. In view of these circumstances, the present invention aims to improve the workability of laying waterproof sheets on the inner surface of tunnels. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides a waterproof sheet deployment assist device for deploying a waterproof sheet on the inner surface of a tunnel, The outer surface is formed in an arch shape facing the inner surface of the tunnel, and the guide frame on which the winding roll of the waterproof sheet can roll is provided. A support base is provided that can be extended and retracted from the guide frame, An operating mechanism that moves the support base between a storage position where it fits within the guide frame and a protruding position where it protrudes from the outer surface and is capable of receiving the winding roll, It is characterized by having the following features. This waterproof sheet deployment assist device allows the winding roll to be received by positioning the support base in a protruding position. In this state, the waterproof sheet unwound from the winding roll can be deployed and fixed to the inner surface of the tunnel. Furthermore, by positioning the support base in a retracted position, the winding roll can be rolled and deployed towards the lower circumferential position of the guide frame. This improves the work efficiency of deploying the waterproof sheet to the inner surface of the tunnel and reduces the burden on workers.

[0007] Preferably, the support bases are provided at each of the multiple circumferentially spaced stages of the guide frame, and the operating mechanism is provided for each support base. By extending and retracting support bases at different stages according to the position of the winding roll, the winding roll can be received by one support base, the winding roll can be rolled from the support base towards a lower position to unfold the waterproof sheet, and the unfolded waterproof sheet can be stretched between two protruding support bases and lifted.

[0008] Preferably, the distance between adjacent support bases at relatively high positions in the circumferential direction of the guide frame is smaller than the distance between adjacent support bases at relatively low positions in the circumferential direction of the guide frame. This reduces the area and weight of the waterproof sheet between adjacent support bases at a high position, and also reduces the load when pushing the protective sheet between the support bases towards the inner surface of the tunnel. At lower elevations, the area of ​​waterproof sheeting that can be deployed at once can be increased. At lower elevations, when pushing the waterproof sheeting up to the inner surface of the tunnel, the proportion of lateral force is larger, so even if a large area of ​​waterproof sheeting is deployed at once, the burden is small.

[0009] Preferably, the support base is formed in a partially cylindrical shape with its axis oriented in the direction of the tunnel axis and open to the inner surface of the tunnel. This ensures that the winding roll, rolling along the circumferential direction of the guide frame from the higher position, is reliably caught by the support base at the protruding position. Furthermore, by retracting the support base, the winding roll can be made to move out of the support base and roll towards the lower position.

[0010] Preferably, the near end of the support base on the side closer to the top of the guide frame in the circumferential direction is connected to the guide frame via a rotating shaft member whose rotation axis is oriented in the direction of the tunnel axis, and the far end of the support base on the side further from the top of the guide frame in the circumferential direction is able to extend and retract from the guide frame. This allows the winding roll, which has rolled along the circumferential direction of the guide frame from the higher position, to be received by the support base at the protruding position. Furthermore, by rotating the support base from the protruding position to the retracted position, the winding roll can be moved out to the lower position.

[0011] Preferably, the guide frame is provided with a support portion that receives the far end of the support base in the storage position. This allows the storage base to be supported by the base support section.

[0012] Preferably, the support base is provided with a plurality of rolling rollers arranged in the circumferential direction of the support base, with their rotational axes oriented in the direction of the tunnel axis. This design allows for smoother unwinding of the waterproof sheet when the winding roll, supported by the protruding support base, rotates (rotates on its own axis) while the rolling rollers move. Additionally, retracting the support base into its storage position allows the winding roll to roll out smoothly from the base.

[0013] Preferably, the top of the guide frame is provided with a lifting means having a sheet-pressing portion over which the waterproof sheet is placed and which can be raised and lowered. This allows the lifting means to push up the waterproof sheet, making it easier to lay the waterproof sheet on the top of the inner surface of the tunnel.

[0014] Preferably, the guide frame includes an arched frame body and a size adjustment frame detachably connected to the circumferential end of the frame body, wherein the circumferential length of the size adjustment frame in the circumferential direction of the guide frame is shorter than the circumferential length of the frame body. This allows the circumference of the guide frame to be expanded or contracted according to the tunnel cross-section, enabling the waterproof sheet tensioning assist device to be adapted to tunnel cross-sections of various sizes.

[0015] Preferably, the support base is provided with a guard plate that closes the space between the support base and the guide frame at the protruding position when viewed from the direction of the tunnel axis. This can prevent a part of the human body, such as a hand, from being inserted between the receiving base and the guide frame at the protruding position. Therefore, when moving the receiving base from the protruding position to the storage position, it is possible to prevent a part of the human body from being sandwiched between the receiving base and the guide frame. As a result, safety can be enhanced.

[0016] The method of the present invention is a method for stretching a waterproof sheet by the waterproof sheet stretching auxiliary device, a step of rolling the wound roll of the waterproof sheet along the circumferential direction of the guide frame to a lower position side to deploy the waterproof sheet on the guide frame; a step of placing a first receiving base disposed on the immediately adjacent lower position side in the circumferential direction of the deployed portion of the waterproof sheet at the protruding position, and receiving the rolled-up roll that has rolled by the first receiving base; a step of pushing up the deployed portion of the waterproof sheet toward the inner surface of the tunnel; a step of fixing the pushed-up portion of the waterproof sheet to the inner surface of the tunnel via a fixing means; a step of further deploying the waterproof sheet downward from the first receiving base by rolling the wound roll along the guide frame to a further lower position side in the circumferential direction by bringing the first receiving base from the protruding position to the storage position; characterized by comprising the above. The step of further deploying is not limited to after the completion of the fixing step, and may be performed before the completion.

[0017] Preferably, in the method for stretching a waterproof sheet according to the present invention, a second receiving base adjacent to the lower position side of the first receiving base is placed at the protruding position, and the rolled-up roll that has rolled is received by the second receiving base; subsequently, a step of pushing up the portion of the waterproof sheet covering the first receiving base toward the inner surface of the tunnel by bringing the first receiving base from the storage position to the protruding position; A step of fixing, via fixing means, a portion of the waterproof sheet pushed up by the first cradle to the inner surface of the tunnel; A step of rolling the winding roll further downward along the guide frame from the second cradle by bringing the second cradle from the protruding position to the storage position, and further unfolding the waterproof sheet downward from the second cradle; It further includes. The step of further unfolding from the second cradle is not limited to after the completion of the step of fixing the portion pushed up by the first cradle, and may be performed before the completion.

[0018] Preferably, in the method for extending a waterproof sheet according to the present invention, by bringing the second cradle after rolling the winding roll to the lower position from the storage position to the protruding position, a portion of the waterproof sheet spanned between the first cradle and the second cradle is pushed upward toward the inner surface of the tunnel; A step of fixing, via fixing means, the spanned portion of the waterproof sheet to the inner surface of the tunnel; It further includes.

Effect of the Invention

[0019] According to the present invention, the workability of the operation of extending the waterproof sheet to the inner surface of the tunnel can be improved.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a front view showing a waterproof sheet extension assisting device according to a first embodiment of the present invention during an operation of extending a waterproof sheet to the inner surface of a tunnel. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a circular portion II in FIG. 1. [Figure 3] FIG. 3 is a side view of an outer peripheral portion of the waterproof sheet extension assisting device along line III-III in FIG. 1. [Figure 4(a)] FIG. 4(a) is a front view showing one of the cradles of the waterproof sheet extension assisting device in a storage position. [Figure 4(b)] Figure 4(b) is a front view along the line IVb-IVb in Figure 3, showing the support base in a protruding position. [Figure 5(a)] Figure 5(a) is a front view showing the waterproof sheet deployment method using the waterproof sheet deployment assist device, specifically the step of positioning the winding roll of the waterproof sheet at the top of the guide frame of the waterproof sheet deployment assist device. [Figure 5(b)] Figure 5(b) is a front view showing the waterproof sheet installation method, specifically the step of fixing the top (0th) portion of the waterproof sheet to the inner surface of the tunnel. [Figure 6(a)] Figure 6(a) is a front view showing the waterproof sheet deployment method in the step of deploying the waterproof sheet up to the second support base. [Figure 6(b)] Figure 6(b) is a front view showing the waterproof sheet installation method, specifically the step of fixing the first layer of the waterproof sheet to the inner surface of the tunnel. [Figure 7(a)] Figure 7(a) is a front view showing the waterproof sheet deployment method in the step of unfolding the waterproof sheet up to the third support base. [Figure 7(b)] Figure 7(b) is a front view showing the waterproof sheet installation method, specifically the step of fixing the second layer of the waterproof sheet to the inner surface of the tunnel. [Figure 8] Figure 8 shows a second embodiment of the present invention, where Figure 8(a) is a front view showing the guide frame of the waterproof sheet tensioning assist device assembled for a relatively small cross-section tunnel. Figure 8(b) is a front view showing the guide frame assembled for a relatively large cross-section tunnel. [Figure 9(a)] Figure 9(a) is a front view showing one of the support bases of the waterproof sheet tensioning assist device according to the third embodiment of the present invention in its stored position. [Figure 9(b)] Figure 9(b) is a front view showing the support base of the third embodiment in a protruding position. [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment (Figures 1-7)> Figure 1 shows tunnel 1 under construction using the NATM method. A primary lining 3 (tunnel perimeter wall) is provided along the excavated ground surface 2. As shown in Figure 2, a waterproof sheet 5 is stretched across the arched inner surface 3a of the primary lining 3, sandwiching a permeable layer 4 made of nonwoven fabric (omitted in drawings other than Figure 2). The material of the waterproof sheet 5 is preferably ethylene vinyl acetate copolymer resin (EVA), but is not limited to this, and may also be other thermoplastic resins such as polyethylene, polypropylene, or polyvinyl chloride.

[0022] The waterproof sheet 5 is, for example, a wide waterproof sheet with a width of 4m to 8m. The wide waterproof sheet is made by joining together two to four 2m wide waterproof sheets in the width direction at a waterproof sheet manufacturing plant. As shown in Figure 1, the waterproof sheet 5 is stretched in the circumferential direction of the tunnel with its width direction oriented in the tunnel axis direction (the direction perpendicular to the plane of the paper in Figure 1). As shown in Figure 2, the stretched waterproof sheet 5 is fixed to the inner surface 3a of the primary lining 3 via fixing means such as an electromagnetic induction welding disc 6 (see Patent Document 1 above). Although not shown in the diagram, a secondary lining is constructed on the inner circumference side (inward in the tunnel radial direction) of the waterproof sheet 5.

[0023] As shown in Figure 1, a waterproof sheet deployment assist device 10 is provided inside the tunnel for deploying the waterproof sheet 5. The waterproof sheet deployment assist device 10 comprises a frame 11, a guide frame 12, a pushing means 20, a support base 30, and an operating mechanism 40. The frame 11 serves as a platform on which workers can climb up and down, and is assembled in a roughly semicircular shape when viewed from the front to match the cross-section of the tunnel.

[0024] As shown in Figure 1, a guide frame 12 is provided on the outer periphery of the support structure 11. The guide frame 12 is formed in an arch shape along the circumferential direction of the inner surface 3a (inner surface of the tunnel) of the primary lining 3. The outer periphery surface 12b of the guide frame 12 faces the inner surface 3a of the tunnel, away from the inner surface in the radial direction of the tunnel. As shown in Figure 3, preferably, a plurality (for example, three) of guide frames 12 are arranged side by side, spaced apart from each other in the axial direction of the tunnel (left-right direction in Figure 3). Note that the number of guide frames 12 is not limited to three; it may be two, four or more, or even just one.

[0025] As shown in Figure 1, a push-up mechanism 20 is provided at the top 12p of each guide frame 12. As shown in Figures 5(a) and 5(b), the push-up mechanism 20 includes a pair of hydraulic lifting cylinders 21. The cylinder body 22 of each lifting cylinder 21 is fixed to the top of the guide frame 12 with its axis oriented vertically. A rod 23 protrudes from the upper end of the cylinder body 22 so as to be able to move back and forth. A seat-pressing part 24, for example, with a circular cross-section, is provided at the upper end of the rod 23. The seat-pressing part 24 is raised and lowered by the movement of the rod 23. The push-up mechanism 20 is controlled by an operation button unit (not shown).

[0026] As shown in Figure 1, multiple support bases 30 are provided symmetrically on the semicircular frame sections 12a on both sides of the top 12p of each guide frame 12. The support bases 30 are installed at multiple positions spaced apart in the longitudinal direction (circumferential direction of the tunnel) of each frame section 12a. When distinguishing these support bases 30 from one another, they are referred to in order from the higher position (closer to the top 12p) to the lower position as the first support base 30A, the second support base 30B, the third support base 30C, the fourth support base 30D, the fifth support base 30E, and so on.

[0027] As shown in Figure 1, the spacing between adjacent support bases 30 at relatively high positions in the circumferential direction of the guide frame 12 is smaller than the spacing between adjacent support bases 30 at relatively low positions in the circumferential direction of the guide frame 12. Here, the spacing between the support bases 30A and 30B of the first and second stages, and the spacing between the support bases 30B and 30C of the second and third stages are narrow, while the spacing between the support bases 30C and 30D of the third and fourth stages, and the spacing between the support bases 30D and 30E of the fourth and fifth stages are wide.

[0028] As shown in Figures 4(a) and 4(b), the general shape of each support base 30 in a front view is a semi-cylindrical shape (partially cylindrical shape) with its axis facing the tunnel axis direction and open to the inner surface 3a side. The support base 30 includes a pair of side arms 31 and a plurality of rolling rollers 32. The side arms 31 are provided at both ends of the support base 30 in the axial direction. The side arms 31 are formed in a generally arc shape. Furthermore, the general shape of the support base 30 in a front view (Figure 4, etc.) is not limited to a curved shape such as a semi-cylindrical or partially cylindrical shape, but may also be a flat plate shape.

[0029] The rolling rollers 32 are formed in a cylindrical shape with their axis of rotation oriented in the axial direction of the support base 30 and consequently in the tunnel axial direction (perpendicular to the plane of the paper in Figure 4(a)). Multiple rolling rollers 32 are arranged at intervals along the longitudinal direction of the side arms 31, which are aligned with the circumferential direction of the support base 30. Both ends of each rolling roller 32 are rotatably connected to and supported by the side arms 31.

[0030] As shown in Figures 4(a) and 4(b), the support base 30 can extend and retract from the guide frame 12 into the inner surface 3a of the tunnel. More specifically, the near end 31p of the side arm 31, which is closer to the top 12p of the guide frame 12 in the longitudinal direction (circumferential direction of the support base 30), is rotatably connected to the guide frame 12 via a rotating shaft member 35. The rotation axis of the rotating shaft member 35 is oriented in the direction of the tunnel axis. Therefore, the support base 30 is rotatable about the rotating shaft member 35. As a result, the far end 31q of the side arm 31, which is further from the top 12p of the guide frame 12 in the longitudinal direction (circumferential direction of the support base 30), can extend and retract from the guide frame 12. Consequently, the support base 30 can extend and retract between a protruding position and a retracted position.

[0031] As shown in Figure 4(a), in the storage position, the support base 30 is entirely contained within the guide frame 12 and recessed from the outer circumferential surface 12b of the guide frame 12. As shown in Figure 4(b), in the protruding position, the far end 31q of the support base 30 protrudes from the outer circumferential surface 12b of the guide frame 12 and is in close proximity to the inner surface 3a of the tunnel.

[0032] As shown in Figure 3, the far ends 31q of the support bases 30 of three (or more) guide frames 12 that are spaced apart in the tunnel axis direction (left-right direction in the figure) are connected by a support beam member 34. The support beam member 34 is formed, for example, in a rectangular cross-section and extends straight in the tunnel axis direction.

[0033] As shown in Figures 4(a) and 4(b), a rectangular concave support portion 14 is provided on the outer circumferential surface 12b of the guide frame 12. The support portion 14 receives and supports the support beam member 34 and, consequently, the far end portion 31q of the support base 30 in the storage position (Figure 4(a)). A convex reinforcing projection 16 is formed on the inner circumferential side of the guide frame 12 at a position corresponding to the support portion 14. The reinforcing projection 16 compensates for the cross-sectional defect of the support portion 14.

[0034] As shown in Figures 3 and 4, an operating mechanism 40 is provided for each support base 30. The operating mechanism 40 causes the support base 30 to extend and retract. Specifically, the operating mechanism 40 includes a hydraulic telescopic cylinder 41. As shown in Figures 4(a) and 4(b), the base end of the cylinder body 42 of the telescopic cylinder 41 is rotatably connected to the guide frame 12 via a base end connecting member 33. A rod 43 protrudes from the tip of the cylinder body 42 so as to be able to move forward and backward. The tip of the rod 43 is rotatably connected to an intermediate connecting member 36 provided in the middle of the circumferential direction of the support base 30. As shown in Figure 4(a), the support base 30 is positioned in the retracted position when the rod 43 is retracted and the telescopic cylinder 41 is contracted. As shown in Figure 4(b), the support base 30 is positioned in the protruding position when the rod 43 is advanced and the telescopic cylinder 41 is extended. The operating mechanism 40 is controlled by an operation button unit (not shown).

[0035] Using the waterproof sheet deployment assist device 10, the waterproof sheet 5 is deployed in the following manner. As shown in Figure 1, the deployment process is carried out after the formation of the primary lining 3. A permeable layer 4 (Figure 2) is pre-installed on the inner surface 3a of the primary lining 3, and electromagnetic induction welding discs 6 are attached to various points on the inner surface 3a with anchors 7 (Figure 2). These preliminary steps can be carried out using the frame 11 of the waterproof sheet deployment support device 10 as scaffolding. Before the start of the tensioning operation, all support bases 30 for each section are in their storage position. Also, the pushing mechanism 20 is retracted.

[0036] As shown in Figure 5(a), the waterproof sheet 5 is wound in a spectacle-like fashion and transported to the tunnel construction site including two winding rolls 5A. The waterproof sheet 5 in the state of winding rolls 5A is then lifted up to the top 12p of the guide frame 12 using a winch (not shown).

[0037] As shown in Figure 5(a), the two winding rolls 5A are separated on the left and right sides in the circumferential direction, with the top portion 12p of the outer surface of the guide frame 12 in between, and are positioned in the portion between the push-up means 20 and the first-stage support base 30A. As a result, the portion 5b between the two winding rolls 5A of the waterproof sheet 5 overlaps the push-up means 20, straddling the pair of sheet push-up portions 24.

[0038] As shown in Figure 5(b), the first support bases 30A (first support bases) on both the left and right sides are then positioned in a protruding position by the operating mechanism 40 for the support bases 30A. Then, the two winding rolls 5A are each rolled along the outer circumferential surface 12b of the guide frame 12 toward the lower circumferential position. As a result, the sheet portion 5b between the two winding rolls 5A of the waterproof sheet 5 is unfolded on the guide frame 12. The rolling winding rolls 5A are caught by the support base 30A on the lower position side immediately adjacent to the unfolded portion 5b. Because the support base 30A is formed in a roughly partially cylindrical shape, the winding rolls 5A can be reliably caught. Alternatively, from a state where the two winding rolls 5A are supported by one support base 30A, one of the two winding rolls 5A may be rolled over the top 12p and supported by the other support base 30A.

[0039] Next, the pair of lifting cylinders 21 of the lifting means 20 are extended upward, raising the pair of sheet pressing parts 24. This pushes up the unfolded sheet portion 5b between the two winding rolls 5A. Furthermore, the top sheet portion 5c of the unfolded sheet portion 5b, which is stretched across the pair of sheet pressing parts 24, is brought close to the top of the inner surface 3a of the tunnel. At this time, the winding rolls 5A in the left and right support bases 30A are rotated, and a portion of the waterproof sheet 5 is unwound from the winding rolls 5A and unfolded. At this time, the rolling rollers 32 of the support bases 30A are rotated, allowing the winding rolls 5A to rotate smoothly and the waterproof sheet 5 to be unwound smoothly.

[0040] Next, as shown in Figure 5(b), the top sheet portion 5c (the pushed-up portion) is fixed to the inner surface 3a of the tunnel via a pre-installed electromagnetic induction welding disc 6. Specifically, the electromagnetic induction heater 8 is applied to the portion of the waterproof sheet 5 that covers the electromagnetic induction welding disc 6, and the electromagnetic induction welding disc 6 is heated by electromagnetic induction to weld the welding resin layer 6a (Figure 2) to the waterproof sheet 5. Since the top sheet portion 5c is close to the inner surface 3a of the tunnel and supported by the pushing-up means 20 so as to be stretched between a pair of sheet pushing portions 24, the worker does not need to lift and support the top sheet portion 5c on their own during the welding and fixing work of the top sheet portion 5c. Therefore, the arduous work can be alleviated. Even if the waterproof sheet 5 and, by extension, the top sheet portion 5c are wide and heavy, the workability is not impaired.

[0041] After the fixing work of the top sheet portion 5c is completed, as shown in Figure 6(a), the second support base 30B on the left side of the guide frame 12 (the second support base adjacent to the lower side of the first support base) is positioned in the protruding position. Then, the first support base 30A (the first support base) is moved from the protruding position to the retracted position. The operation to move the support base 30B to the protruding position and the operation to move the support base 30A to the retracted position may be performed before the completion of the fixing work of the top sheet portion 5c.

[0042] As shown by the dashed line in Figure 6(a), the winding roll 5A abuts against the outer surface 12b of the guide frame 12 and separates from the support base 30A as the support base 30A retracts to its storage position. Furthermore, the winding roll 5A rolls further down the outer surface 12b of the guide frame 12 in the circumferential direction. Consequently, the waterproof sheet 5 is further unfolded below the support base 30A. As shown by the solid line in Figure 6(a), the rolling winding roll 5A is caught by the support base 30B on the lower side immediately adjacent to the unfolded portion. Because the support base 30B is formed in a roughly partially cylindrical shape, the winding roll 5A can be reliably caught.

[0043] As shown in Figure 6(b), the first support 30A is then moved from its storage position to a protruding position. This causes the first sheet portion 5d, which is stretched between the support 30A and the pushing means 20 of the waterproof sheet 5, to be pushed up toward the inner surface 3a of the tunnel and stretched along the inner surface 3a. The sheet portion 5d includes the portion of the waterproof sheet 5 that overlaps the support 30A.

[0044] The sheet portion 5d (the pushed-up portion) is welded and fixed to the inner surface 3a of the tunnel via a pre-installed electromagnetic induction welding disc 6. Since the sheet portion 5d is supported by being pushed up by the support base 30A at the protruding position and the pushing-up means 20, there is no need to manually lift and support the sheet portion 5d during the fixing work. Therefore, the arduous work can be alleviated. Even if the sheet portion 5d is wide and heavy, the workability is not impaired.

[0045] As shown in Figure 7(a), the second support base 30B is moved from the protruding position to the retracted position, preferably before or after the fixing process of the sheet portion 5d to the inner surface 3a of the tunnel. As a result, the winding roll 5A comes out from the support base 30B and rolls towards the lower position on the outer surface of the guide frame 12. Consequently, the waterproof sheet 5 is further unfolded below the support base 30B.

[0046] The third support base 30C on the lowest position closest to the unfolding section is pre-positioned to protrude. This ensures that the rolling winding roll 5A is caught by the support base 30C. Because the support base 30C is formed in a roughly partially cylindrical shape, it can reliably catch the winding roll 5A.

[0047] As shown in Figure 7(b), the support base 30B is then moved from its storage position to a protruding position. This pushes up the portion of the waterproof sheet 5 that overlaps the support base 30B, and stretches the second sheet portion 5e, which is stretched between the support bases 30A and 30B, so that it is close to the inner surface 3a of the tunnel. The sheet portion 5e is then welded and fixed to the inner surface 3a of the tunnel via the electromagnetic induction welding disc 6 that has been installed in advance. Since the sheet portion 5e is pushed up and supported by the support bases 30A and 30B in their protruding positions, there is no need for workers to manually lift and support the sheet portion 5e. Therefore, the arduous work is alleviated, and even if the sheet portion 5e is wide and heavy, the work efficiency is not impaired.

[0048] Although not shown in the diagram, around the same time that the sheet portion 5e is fixed to the inner surface 3a of the tunnel, the third support base 30C is moved from the protruding position to the retracted position, thereby transferring the winding roll 5A from the support base 30C to the lower position. The winding roll 5A is received by the fourth support base 30D (Figure 1), which has been set to the protruding position in advance. Because the support base 30D is formed in a roughly partially cylindrical shape, it can reliably receive the winding roll 5A.

[0049] By repeatedly performing this operation sequentially toward the lower circumferential position of the guide frame 12, the waterproof sheet 5 can be stretched from the top to the bottom of the inner surface 3a of the tunnel. Each support base 30 on each level constitutes a "first support base" with respect to the support base 30 immediately adjacent to it at a lower position. In addition, each support base 30 on each level except the first level constitutes a "second support base" with respect to the support base 30 immediately adjacent to it at a higher position.

[0050] As shown in Figure 1, at higher positions in the tunnel, the spacing between adjacent support bases 30A, 30B and between 30B, 30C is relatively small. Therefore, the area and weight of the sheet portions 5e, 5f between these support bases can be reduced, and the load on support bases 30B, 30C when pushing up the sheet portions 5e, 5f by support bases 30B, 30C can be reduced. At lower positions in the tunnel, the spacing between adjacent support bases 30C, 30D and between 30D, 30E is relatively large. Therefore, the area of ​​the sheet portions 5g, 5h that can be stretched at once between these support bases can be increased. At lower positions, when pushing up the sheet portions 5g, 5h toward the inner surface 3a of the tunnel, the proportion of the lateral force component is larger. Therefore, even if the area of ​​the sheet portions 5g, 5h is large, the load on support bases 30D, 30E can be reduced.

[0051] In terms of personnel requirements, at least one worker A is needed to weld the unfolded sheet portion 5b (5c~5h) to the inner surface 3a of the tunnel, and no worker is needed to lift and support the sheet portion 5b during welding. Therefore, for example, if there are two workers, one can be in charge of unfolding the waterproof sheet 5 on the left side of the circumferential top 12p of the guide frame 12, and the other can be in charge of unfolding the waterproof sheet 5 on the right side of the circumferential top 12p of the guide frame 12. This allows the unfolding of the waterproof sheet 5 on both the left and right sides of the guide frame 12 to be carried out simultaneously by a small number of people, thereby shortening the construction period.

[0052] Next, other embodiments of the present invention will be described. In the following embodiments, components that overlap with those described in the previously described embodiments are denoted by the same reference numerals in the drawings and their descriptions are omitted. <Second Embodiment (Figure 8)> As shown in Figure 8, in the second embodiment of the present invention, the guide frame 12 includes one or more arch-shaped frame bodies 13 and a size adjustment frame 15. The frame bodies 13 occupy most of the circumferential portion (e.g., 90% or more) of the guide frame 12.

[0053] The circumferential length of the size adjustment frame 15 of the guide frame 12 is sufficiently shorter than the circumferential length of the frame body 13. As shown in Figure 8(a), the size adjustment frame 15 is detachably connected to the circumferential end of the frame body 13. As shown in Figure 8(b), for example, the size adjustment frame 15 is installed so as to be sandwiched between two frame bodies 13 and connected to each frame body 13. The size adjustment frame 15 may be provided at the circumferential end of the guide frame 12, i.e., at the bottom of the guide frame 12.

[0054] According to the second embodiment, the circumference of the guide frame 12 can be expanded or contracted by attaching or detaching the size adjustment frame 15 to the guide frame 12, depending on the tunnel cross-section. That is, as shown in Figure 8(b), when the tunnel cross-section is large, the circumference of the guide frame 12 can be expanded by attaching the size adjustment frame 15. As shown in Figure 8(a), when the tunnel cross-section is small, the circumference of the guide frame 12 can be shortened by removing the size adjustment frame 15. This makes the waterproof sheet tensioning assist device 10 adaptable to tunnel cross-sections of various sizes.

[0055] <Third Embodiment (Figure 9)> As shown in Figure 9(a), in the waterproof sheet tensioning assist device 10C according to the third embodiment of the present invention, guard plates 37 are provided on each support base 30. The guard plate 37 has an arc-shaped recessed upper edge 37ae, a convex arc-shaped tip edge 37f, and a straight side edge 37be, and is formed in a generally triangular plate shape. The thickness of the guard plate 37 is preferably about 10 mm, but is not necessarily limited to this.

[0056] The upper edge 37ae of the guard plate 37 abuts against the lower surface 31ab (the surface opposite to the surface on which the rolling roller 32 is provided) of the roughly arc-shaped arm portion 31a of the side arm 31, from the intermediate connecting member 36 to the far end portion 31q, and is joined by welding or the like. As a result, the guard plate 37 hangs down from the arm portion 31a. Note that the means of joining the guard plate 37 and the side arm 31 is not limited to welding; it may also be bolted or the like. The guard plate 37 and the side arm 31 may also be integrally formed from a single steel material.

[0057] Preferably, the guard plate 37 and the guide frame 12 are positioned so close together in the tunnel axis direction (the direction perpendicular to the plane of the paper in Figure 9) that it is impossible to insert a hand between them.

[0058] As shown in Figure 9(a), when the support base 30 is in the storage position, the inverted triangular hanging end 37c formed by the leading edge 37f and the side edge 37be of the guard plate 37 protrudes downward from the guide frame 12.

[0059] As shown in Figure 9(b), when the support base 30 is in the protruding position, in a front projection view from the tunnel axis direction (the direction perpendicular to the plane of the paper in Figure 9), a portion 37b of the guard plate 37 overlaps with the outer peripheral portion 12d of the guide frame 12, including the outer peripheral surface 12b. Specifically, the roughly rectangular side portion 37b of the guard plate 37 along the side edge 37be connecting the intermediate connecting member 36 and the hanging end portion 37c overlaps with the outer peripheral portion 12d of the guide frame 12 in a front projection view. Furthermore, the roughly triangular space 10s formed by the side arm 31, which stands upright above the guide frame 12, and the guide frame 12 is blocked in a front projection view by the fan-shaped guard plate portion 37a on the upper edge 37ae side of the side portion 37b of the guard plate 37.

[0060] Therefore, it is not possible to insert a part of the human body, such as a hand, into the space 10s. Consequently, when the support base 30 is retracted from the protruding position (Figure 9(b)) to the stored position (Figure 9(a)), it is possible to prevent a part of the human body from being caught between the descending side arm 31 and the guide frame 12. This enhances safety.

[0061] The present invention is not limited to the embodiments described above, and various modifications can be made without violating its spirit. For example, the support base 30 may be displaced between the protruding position and the stored position by being moved in parallel. There should be at least one support stand 30. The pushing mechanism 20 may be omitted. [Industrial applicability]

[0062] This invention can be applied, for example, to the construction of mountain tunnels. [Explanation of Symbols]

[0063] 1 Tunnel 3. Primary lining (tunnel perimeter wall) 3a Inner surface (inner surface of tunnel) 5 Waterproof sheet 5A Winding Roll 5b Expanded portion 5c~5h Sheet portion (overlapping portion, pushed-up portion, spanned portion) 6. Electromagnetic induction welding disc (fixing means) 10 Waterproof sheet tensioning assist device 10C Waterproof Sheet Deployment Assist Device 10s Space between the support base and the guide frame 12 Guide Frames 12b Outer surface 12p top 13 Frame body 14 support section 15-size adjustable frame 20 Push-up means 21 Lifting Cylinder 24 Sheet press top 30 support stand 30A First support base (first support base) 30B~30E Support stands for the 2nd to 5th tiers (1st support stand, 2nd support stand) 31p proximal end 31q far end 32 Rolling rollers 35 Rotating shaft member 40 Operating mechanism 41 Telescopic Cylinder 37 Guard plate 37a Guard plate section

Claims

1. A waterproof sheet deployment assist device for deploying a waterproof sheet on the inner surface of a tunnel, The outer surface is formed in an arch shape facing the inner surface of the tunnel, and the guide frame on which the winding roll of the waterproof sheet can roll is provided. A support base is provided that can be extended and retracted from the guide frame, An operating mechanism that moves the support base between a storage position where it fits within the guide frame and a protruding position where it protrudes from the outer surface and is capable of receiving the winding roll, A waterproof sheet tensioning assist device characterized by being equipped with the following features.

2. The waterproof sheet tensioning assist device according to claim 1, wherein the support bases are provided at each of the multiple stages spaced apart in the circumferential direction of the guide frame, and the operating mechanism is provided for each support base.

3. The waterproof sheet tensioning assist device according to claim 2, wherein the distance between adjacent support bases at a relatively high position in the circumferential direction of the guide frame is smaller than the distance between adjacent support bases at a relatively low position in the circumferential direction of the guide frame.

4. The waterproof sheet tensioning assist device according to claim 1, wherein the support base is formed in a partially cylindrical shape with its axis oriented in the direction of the tunnel axis and open to the inner surface of the tunnel.

5. The near end of the support base on the side closest to the top of the guide frame in the circumferential direction is connected to the guide frame via a rotating shaft member whose rotation axis is oriented in the direction of the tunnel axis. The waterproof sheet tensioning assist device according to claim 1, wherein the far end of the support base on the side furthest from the top of the guide frame in the circumferential direction is capable of extending and retracting from the guide frame.

6. The waterproof sheet tensioning assist device according to claim 5, wherein the guide frame is provided with a support portion that receives the far end of the support base in the storage position.

7. The waterproof sheet tensioning assist device according to claim 1, wherein the support base is provided with a plurality of rolling rollers arranged in the circumferential direction of the support base, with the axis of rotation oriented in the direction of the tunnel axis.

8. The waterproof sheet tensioning assist device according to any one of claims 1 to 7, wherein the top of the guide frame is provided with a lifting means having a sheet pressing portion over which the waterproof sheet is placed and which can be raised and lowered.

9. The waterproof sheet tensioning assist device according to any one of claims 1 to 7, wherein the guide frame includes an arched frame body and a size adjustment frame detachably connected to the circumferential end of the frame body, and the circumferential length of the size adjustment frame in the circumferential direction of the guide frame is shorter than the circumferential length of the frame body.

10. The waterproof sheet tensioning assist device according to claim 1, wherein the support base is provided with a guard plate that closes the space between the support base and the guide frame at the protruding position when viewed from the direction of the tunnel axis.

11. A method for deploying a waterproof sheet using the waterproof sheet deployment assist device described in claim 2 or 3, The process of rolling the winding roll of the waterproof sheet along the circumferential direction of the guide frame toward the lower position to unfold the waterproof sheet onto the guide frame, The first support base, positioned on the lowest circumferential side of the unfolded portion of the waterproof sheet, is set to the protruding position, and the first support base is used to receive the rolling winding roll. The steps include pushing up the unfolded portion of the waterproof sheet toward the inner surface of the tunnel, The steps include: fixing the pushed-up portion of the waterproof sheet to the inner surface of the tunnel via a fixing means; The process involves moving the first support from the protruding position to the storage position, thereby rolling the winding roll along the guide frame to an even lower position in the circumferential direction, and further unfolding the waterproof sheet below the first support; A method for laying a waterproof sheet on the inner surface of a tunnel, characterized by comprising the following features.

12. The second support base adjacent to the lower position side of the first support base is set to the protruding position, and the second support base is used to receive the winding roll that has rolled in, Next, the first support is moved from the storage position to the protruding position, thereby pushing up the portion of the waterproof sheet that covers the first support toward the inner surface of the tunnel. The process of fixing the portion of the waterproof sheet that has been pushed up by the first support to the inner surface of the tunnel via a fixing means, The process of moving the second support from the protruding position to the storage position, thereby rolling the winding roll along the guide frame to a position even lower than the second support, and further unfolding the waterproof sheet below the second support, A method for laying a waterproof sheet according to claim 11, further comprising the above.

13. The process involves moving the second support base from the storage position to the protruding position after rolling the winding roll toward the lower position, thereby pushing up the portion of the waterproof sheet that is stretched between the first support base and the second support base toward the inner surface of the tunnel. The steps include fixing the stretched portion of the waterproof sheet to the inner surface of the tunnel via fixing means, A method for laying a waterproof sheet according to claim 12, further comprising the above.

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