Backfill material filling method and backfill material filling apparatus

Abstract

To provide a backfilling material filling method and a backfilling material filling device capable of reducing labor for carrying a backfilling material and easily carrying the backfilling material.SOLUTION: A backfill material filling method according to one embodiment is a material filling method for filling a backfill material in a friction cut 6 for reducing peripheral surface friction generated in a caisson 1 when the caisson 1 is settled in the ground. The backfill material filling method includes a process of installing a pipe 11 for conveying the backfill material on an outer peripheral side 1b of the caisson 1 in a plan view, a process of connecting an elector 14 for conveying the backfill material to one end of the pipe 11, and a process of conveying the backfill material inside the pipe 11 by feeding compression air to the elector 14 and supplying the backfill material from the pipe 11 to the frictional cut 6.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a backfilling material filling method and a backfilling material filling device for filling friction cuts with backfilling material to reduce peripheral friction occurring in caissons. [Background technology]

[0002] Patent Document 1 describes a method for sinking a pneumatic caisson. The pneumatic caisson has a foundation bottom provided at its lower end and sidewalls provided on the foundation bottom. The foundation bottom has a cutting edge provided at its lower end facing downward and a horizontal slab provided at the upper end of the cutting edge to separate the working chamber. This pneumatic caisson has a co-sag suppression structure. The co-sag suppression structure includes a friction reduction section formed by a space for storing stabilizing fluid provided between the sidewalls and the ground, and an earth retaining section provided around the outer periphery of the friction reduction section. The stabilizing fluid is stored in the friction reduction section in parallel with the sinking of the pneumatic caisson's main body.

[0003] Patent Document 2 describes a method for sinking a pneumatic caisson. In this pneumatic caisson, the peripheral wall of the cutting edge is formed to protrude outward from the outer peripheral walls of the middle and top sections of the caisson. This reduces frictional resistance between the ground and the outer peripheral walls of the middle and top sections of the caisson when the caisson sinks. In this sinking method, a replacement column is constructed in advance at the location of the ground where the cutting edge of the pneumatic caisson will be placed. The replacement column is made of a soil material with lower cohesion than the ground. The soil material is made of single-grain crushed stone or single-grain gravel.

[0004] Patent Document 3 describes a settlement accelerator that accelerates the settlement of caissons. The settlement accelerator contains, per cubic meter, 700 to 1,000 kg by weight of sand, 300 to 600 kg by weight of water, 1 to 6 kg of water-soluble polymeric cellulose, a water-soluble polymer stabilizer, and sand partially replaced with 0 to 800 kg by weight of mineral fine powder. The settlement accelerator is poured into the friction cut section on the peripheral surface every time one lot of caissons settles. When the settlement of the caissons is complete, a neutralizer and a water-soluble polymeric decomposer are injected into the settlement accelerator and stirred.

[0005] Patent Document 4 describes a method for sinking a caisson. A protrusion that forms a friction cut section is formed on the outer periphery of the lower part of the caisson. The friction cut section creates an overexcavation gap around the caisson. When the caisson is sunk, a polymeric water-absorbent resin is injected into the overexcavation gap. When the caisson reaches a predetermined depth, the polymeric water-absorbent resin is replaced with a layer of hardener.

[0006] Patent Document 5 describes a caisson. The caisson has a cutting edge and a cylindrical part extending upward from the cutting edge. A gap that functions as a friction cut is formed on the outer periphery of the cylindrical part. The gap is filled with a plastic gel, which is a mixed liquid containing water and a plastic strength adjuster. The plastic gel solidifies when a solidifying agent is added, and becomes integrated with the surrounding ground located around the caisson. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2018-150761 [Patent Document 2] Patent No. 6208496 [Patent Document 3] Japanese Patent Application Publication No. 10-306455 [Patent Document 4] Japanese Patent Application Publication No. 8-158378 [Patent Document 5] Patent No. 2548057 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when a caisson with a friction cut is lowered into the ground, the caisson may pull in the surrounding ground. In this case, it may be necessary to supply backfill material to the friction cut and perform backfilling. Conventionally, the backfill material has been transported using heavy machinery such as a backhoe. However, in narrow work sites, it may not be possible to use heavy machinery. Also, the backfill material has sometimes been transported manually. However, when transporting the backfill material manually, it is laborious and may not be easy to transport the backfill material.

[0009] The present disclosure aims to provide a backfilling material filling method and a backfilling material filling device that reduce the labor required to transport the backfilling material and facilitate the transportation of the backfilling material. [Means for solving the problem]

[0010] (1) The backfill material filling method according to the present disclosure is a material filling method for filling backfill material into friction cuts that reduce peripheral friction that occurs in a caisson when the caisson is lowered into the ground. The backfill material filling method includes the steps of: installing a pipe for transporting the backfill material around the outer periphery of the caisson in a plan view; connecting an ejector for transporting the backfill material to one end of the pipe; and feeding compressed air into the ejector to transport the backfill material inside the pipe and supplying the backfill material from the pipe to the friction cuts.

[0011] In this backfill material filling method, a pipe for transporting the backfill material is installed around the periphery of the caisson in a plan view. An ejector for transporting the backfill material is connected to one end of the pipe. Compressed air is then fed into the ejector, transporting the backfill material inside the pipe and supplying it to the friction cut from the pipe. Thus, the backfill material is sucked into the ejector, which transports it and supplies it to a specified location in the caisson. The backfill material can also be easily transported to locations far from the ejector. Therefore, even in a narrow site, the backfill material can be easily transported by installing a pipe around the periphery of the caisson in a plan view and passing the backfill material through the pipe and using the ejector to transport it. Therefore, the backfill material can be easily transported and filled into the friction cut located on the periphery of the caisson in a plan view.

[0012] (2) In (1) above, the pipe may have multiple outlets through which the backfill material exits the pipe. In the pipe installation step, the pipe may be installed so that the pipe surrounds the caisson in plan view and the multiple outlets are aligned along the outer periphery of the caisson in plan view. In this case, the pipe transporting the backfill material surrounds the caisson in plan view and the multiple outlets are aligned along the outer periphery of the caisson. Therefore, the backfill material can be supplied from each of the multiple outlets aligned along the circumferential direction of the caisson, making it easy to transport the backfill material to the desired position in the caisson.

[0013] (3) In the above (2), the multiple outlets may include a first outlet and a second outlet located at a different position from the first outlet. The first outlet and the second outlet may have valves. The step of supplying the backfill material may include a step of supplying the backfill material from the first outlet by opening the valve of the first outlet and closing the valve of the second outlet, and a step of supplying the backfill material from the second outlet by closing the valve of the first outlet and opening the valve of the second outlet. In this case, the backfill material can be supplied sequentially from each of the first outlet and the second outlet, thereby efficiently transporting the backfill material to each section of the caisson.

[0014] (4) In any of the above (1) to (3), the backfill material may be single-grain crushed stone. In this case, the backfill material transported inside the pipe is single-grain crushed stone, which reduces adhesion of the backfill material to the inside of the pipe. Therefore, the backfill material can be transported more efficiently.

[0015] (5) In any of (1) to (4) above, the particle size of the backfilling material may be 2.5 mm or more and 13 mm or less. In this case, the particle size of the backfilling material is 2.5 mm or more, which can reduce adhesion of the backfilling material to the inside of the pipe. The particle size of the backfilling material is 13 mm or less, which can more efficiently transport the backfilling material by the ejector.

[0016] (6) In any of the above (1) to (5), the pipe may have an outlet portion from which the backfill material exits, and the outlet portion may include a hose for discharging the backfill material. In this case, the hose for discharging the backfill material is lightweight and can be moved freely, allowing for more efficient filling of the backfill material.

[0017] (7) In any of (1) to (6) above, the pipe may include an L-shaped pipe. The backfilling material filling method may include a step of checking whether the backfilling material is clogged in the L-shaped pipe after the step of supplying the backfilling material. Of the pipes through which the backfilling material passes, the L-shaped pipe is a location where clogging of the backfilling material is likely to occur. Therefore, by checking whether the backfilling material is clogged in the L-shaped pipe as described above, clogging of the backfilling material during transportation can be prevented.

[0018] (8) The backfill material filling device according to the present disclosure is a backfill material filling device that fills backfill material into a friction cut that reduces peripheral friction that occurs on a caisson when the caisson is lowered into the ground. The backfill material filling device includes a pipe installed on the outer periphery of the caisson in a plan view, an ejector connected to one end of the pipe, and a compressor that sends compressed air to the ejector. The compressor sends compressed air to the ejector to transport the backfill material inside the pipe, and the backfill material filling device supplies the backfill material from the pipe to the friction cut.

[0019] In this backfill material filling device, an ejector for transporting the backfill material is connected to one end of a pipe installed around the periphery of the caisson in a plan view. Compressed air is sent from a compressor to the ejector, transporting the backfill material inside the pipe. The backfill material is then supplied to the friction cut from this pipe. The backfill material is then sucked into the ejector, which then transports the backfill material and supplies it to a designated location in the caisson. Therefore, similar to the backfill material filling method described above, the backfill material filling device can easily transport the backfill material to locations far from the ejector. Therefore, even in a narrow site, the backfill material can be easily transported by the ejector transporting the backfill material through a pipe installed around the periphery of the caisson in a plan view. Therefore, the backfill material can be easily transported and filled into the friction cut located around the periphery of the caisson in a plan view. [Effects of the Invention]

[0020] According to the present disclosure, the labor required for transporting backfilling material can be reduced, and the backfilling material can be easily transported. [Brief explanation of the drawings]

[0021] [Figure 1] Figures 1(a), 1(b) and 1(c) are cross-sectional views that schematically show how a caisson with a friction cut sinks. [Figure 2] Figure 2 is a cross-sectional view showing how lubricants are supplied to the outer periphery of the caisson. [Figure 3] FIG. 3 is a plan view showing a backfilling material filling device and a caisson according to the embodiment. [Figure 4] FIG. 4 is a perspective view showing an example of a backfill material and an ejector. [Figure 5] FIG. 5 is a diagram schematically illustrating an ejector of the backfilling material filling apparatus according to the embodiment. [Figure 6] Fig. 6(a) is a diagram showing a pipe and an outlet of the backfilling material filling device according to the embodiment, and Fig. 6(b) is a diagram showing an L-shaped pipe of the backfilling material filling device according to the embodiment. [Figure 7] FIG. 7 is a flowchart illustrating an example of steps of a backfilling material filling method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of a backfilling material filling apparatus and a backfilling material filling method according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations will be omitted as appropriate. The drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional proportions and the like are not limited to those shown in the drawings.

[0023] 1(a), 1(b), and 1(c) are cross-sectional views schematically showing a caisson 1 according to an embodiment. The caisson 1 is a pneumatic caisson. The caisson 1 comprises a caisson body 2. The caisson body 2 has a lower side wall 3 with a cutting edge 3b formed at its lower end. The caisson 1 is constructed by a pneumatic caisson construction method.

[0024] In the pneumatic caisson method, for example, a block 5, which is a reinforced concrete structure, is constructed on the ground surface S. A work chamber 4 is provided at the bottom of the caisson 1. Compressed air equivalent to the groundwater pressure is pumped into the work chamber 4 to prevent groundwater from seeping into the work chamber 4. Excavation and soil removal are carried out inside the work chamber 4 to lower the caisson structure 2, which is then used as the foundation for a structure such as a bridge, a sewage pumping station, an underground regulating pond, a shield tunnel shaft, or a road tunnel.

[0025] The caisson 1 has friction cuts 6 that reduce the peripheral friction that occurs on the caisson 1 when the caisson 1 is lowered into the ground G. The friction cuts 6 are recesses that are recessed from the outer periphery of the lower side wall 3 in a plan view and extend from the lower side wall 3 to the upper end of the caisson 1. For example, the depth (recess amount) of the friction cuts 6 relative to the outer periphery 1b of the caisson 1 in a plan view is 50 mm. However, the recess amount of the friction cuts 6 is not limited to 50 mm and can be changed as appropriate.

[0026] The friction cuts 6 are formed so as to surround the caisson 1 in plan view. By having the friction cuts 6 in the caisson 1, a gap is created between the outer periphery of the friction cuts 6 and the ground G when the caisson 1 is lowered into the ground G, thereby reducing the friction force on the peripheral surface of the caisson 1 during subsidence.

[0027] As shown in Figure 2, the caisson 1 may have a lubricant injection device 7 that injects lubricant L onto the outer periphery 1b of the caisson 1. The lubricant injection device 7 has a pipeline 7b that extends downward from the top of the caisson 1 and extends to the outer periphery 1b of the caisson 1. The lubricant injection device 7 may inject lubricant L onto the outer periphery 1b of the caisson 1 through the pipeline 7b, thereby reducing the frictional force on the outer periphery 1b of the caisson 1.

[0028] As shown in Figure 1(b), when a caisson 1 having a friction cut 6 is lowered, the ground G in contact with the caisson body 2 is pulled downward, which may cause the ground G to subside or to be displaced horizontally. To avoid this, as shown in Figure 1(c), backfill material M is piled up in the area P on the ground surface S where the periphery 1b of the caisson 1 is located, and the amount of ground G that is pulled downward is filled in with the backfill material M, thereby preventing deformation of the surrounding ground. The backfill material M includes, for example, at least one of sand and crushed stone.

[0029] As described above, by placing the backfill material M on the outer periphery 1b of the caisson 1 in a plan view, deformation of the ground G can be prevented. However, a problem can arise in that the backfill material M is not easy to transport. For example, if the backfill material M is transported and filled by hand, a great deal of effort is required, especially when placing the backfill material M around a large caisson 1. It is also possible to use heavy machinery to transport the backfill material M. However, if the site of the caisson 1 is narrow, it may be difficult to use heavy machinery.

[0030] FIG. 3 is a plan view that schematically shows the caisson 1 and the backfilling material filling device 10 according to this embodiment in a plan view. In FIG. 3, the illustration of the caisson 1 is simplified. In this embodiment, the above-mentioned problems can be solved by providing the backfilling material filling device 10 that transports the backfilling material M. The backfilling material filling device 10 will be described below.

[0031] The backfilling material supplying device 10 supplies backfilling material M to the friction cut 6, which reduces the peripheral friction that occurs on the caisson 1 when the caisson 1 is lowered into the ground G. As shown in FIG. 1(c), the friction cut 6 may be a recess extending from the lower sidewall 3 to the upper end of the caisson 1, or may be a portion formed above a plate provided outside the cutting edge 3b in a plan view. This plate is, for example, a steel plate with a thickness of 25 mm. This plate is provided so as to surround the lower sidewall 3 in a plan view. In this way, the configuration of the friction cut 6 can be modified as appropriate.

[0032] As shown in FIG. 3, for example, the caisson 1 is rectangular in plan view. However, the shape of the caisson 1 in plan view may be circular and is not particularly limited. The backfilling material filling device 10 includes, for example, a pipe 11 installed on the outer periphery 1b of the caisson 1 in plan view, and a material conveying device 12 connected to one end of the pipe 11. The pipe 11 is, for example, a steel pipe. However, the pipe 11 may also be, for example, a PVC pipe, and the material of the pipe 11 is not particularly limited. As an example, the pipe 11 is a circular pipe. In this case, the inner diameter of the pipe 11 is, for example, 100 mm.

[0033] The pipe 11 has a plurality of outlets 13, which are portions through which the backfill material M exits the pipe 11. The backfill material filling device 10 is capable of discharging the backfill material M from each of the plurality of outlets 13. The pipe 11 is arranged so as to extend along the outer periphery 1b of the caisson 1 in a plan view. The plurality of outlets 13 are arranged, for example, at equal intervals. In this case, the intervals between the outlets 13 are, for example, 10 m. However, the intervals between the outlets 13 are not particularly limited.

[0034] In this embodiment, the backfilling material filling device 10 has a plurality of (for example, two) pipes 11. By providing a plurality of pipes 11 extending along the outer periphery 1b of the caisson 1 in this manner, the backfilling material M can be transported along each of the plurality of pipes 11, making it easy to transport the backfilling material M.

[0035] For example, in a plan view, at least a portion of the pipes 11 are arranged to extend in an L-shape. For example, one of the two pipes 11 extends along a first direction D1 which is the circumferential direction of the caisson 1 in a plan view, and the other of the two pipes 11 extends along a second direction D2 which is the circumferential direction of the caisson 1 in a plan view. As an example, the first direction D1 is the clockwise direction of the caisson 1 in a plan view, and the second direction D2 is the counterclockwise direction of the caisson 1 in a plan view.

[0036] For example, the multiple outlets 13 include a first outlet 13a and a second outlet 13b that is located at a different position from the first outlet 13a. The first outlet 13a is located closer to the material conveying device 12 than the second outlet 13b. In this embodiment, the multiple outlets 13 include the first outlet 13a, the second outlet 13b, the third outlet 13c, the fourth outlet 13d, the fifth outlet 13e, the sixth outlet 13f, the seventh outlet 13g, the eighth outlet 13h, the ninth outlet 13j, the tenth outlet 13k, the eleventh outlet 13m, the twelfth outlet 13n, the thirteenth outlet 13p, and the fourteenth outlet 13q.

[0037] The first outlet portion 13a, the second outlet portion 13b, the third outlet portion 13c, the fourth outlet portion 13d, the fifth outlet portion 13e, the sixth outlet portion 13f, the seventh outlet portion 13g, the eighth outlet portion 13h, the ninth outlet portion 13j, the tenth outlet portion 13k, the eleventh outlet portion 13m, the twelfth outlet portion 13n, the thirteenth outlet portion 13p and the fourteenth outlet portion 13q are arranged at different positions from each other. Arranged in order from closest to the material conveying device 12 are first outlet 13a, second outlet 13b, third outlet 13c, fourth outlet 13d, fifth outlet 13e, sixth outlet 13f, seventh outlet 13g, eighth outlet 13h, ninth outlet 13j, tenth outlet 13k, eleventh outlet 13m, twelfth outlet 13n, thirteenth outlet 13p, and fourteenth outlet 13q. The above describes an example in which the number of outlets 13 in the pipe 11 is 14. However, the number of outlets 13 may be other than 14 and is not particularly limited.

[0038] The material conveying device 12 includes an ejector 14 connected to one end of the pipe 11, a compressor 15 that sends compressed air to the ejector 14, and a pipe line 16 that connects the ejector 14 and the compressor 15 to each other. The ejector 14 receives compressed air from the compressor 15 to suck the backfill material M into the pipe 11 and conveys the backfill material M to each of the multiple outlet portions 13. The backfill material M is conveyed from the material conveying device 12 through the pipe 11 to the outlet portions 13.

[0039] FIG. 4 is a diagram schematically showing the ejector 14 and the backfill material M. FIG. 5 is a partial cross-sectional view schematically showing the internal structure of the ejector 14. The material transport device 12 may further have a vessel 12b that stores the backfill material M. In this case, the backfill material M can be transported while stored in the vessel 12b. For example, the backfill material M is stored in sandbags, and the backfill material M removed from the sandbags is stored in the vessel 12b.

[0040] When only the transportability of the backfill material M is considered, it is desirable that water not be supplied to the backfill material M. However, water may be supplied to the backfill material M before it is transported. In this case, the generation of dust when the backfill material M comes out from the end of the pipe can be suppressed. However, the amount of water supplied to the backfill material M is set to an amount that does not cause blockage inside the pipe. Water is sprayed onto the backfill material M, for example, by a high-pressure washer.

[0041] The ejector 14 transports the backfill material M stored in, for example, the vessel 12b. The ejector 14 includes an inlet pipe 14b through which compressed air K is introduced, a pair of branch pipes 14c branching from the inlet pipe 14b, a junction pipe 14d where the pair of branch pipes 14c join, a conveyance pipe 14f extending from the junction pipe 14d, and a suction pipe 14g that sucks in the backfill material M. The conveyance pipe 14f is connected to the pipe 11 via, for example, a flexible hose 14h. For example, the suction pipe 14g sucks the backfill material M stored in the vessel 12b into the inside of the ejector 14 while in contact with the backfill material M.

[0042] The ejector 14 accelerates the compressed air K from the compressor 15 inside the ejector 14. The compressed air K from the compressor 15 is sent into the inside of the inlet pipe 14b. The compressed air K sent into the inside of the inlet pipe 14b flows into each of the pair of branch pipes 14c, passes through each branch pipe 14c, and joins at the junction pipe 14d. The junction pipe 14d is located at the end of each branch pipe 14c opposite the inlet pipe 14b. The compressed air K joined at the junction pipe 14d flows from the junction pipe 14d through the conveyance pipe 14f along the pipe 11. The suction pipe 14g is located upstream of the pair of branch pipes 14c in the conveyance path of the backfill material M.

[0043] As the compressed air K flows through the ejector 14, the flow of the compressed air K accelerates, generating a negative pressure inside the suction pipe 14g located upstream of the branch pipes 14c. This negative pressure causes the backfilling material M to be sucked from the suction pipe 14g into the junction pipe 14d and the conveying pipe 14f. Then, inside the pipe 11 connected to the conveying pipe 14f, the backfilling material M is conveyed toward the outlet 13.

[0044] The compressor 15 sends compressed air K to the ejector 14 via the pipeline 16. The pipeline 16 is, for example, a flexible pipe (a hose as an example). The compressor 15 may be, for example, a compressor that sends compressed air K equivalent to groundwater pressure to the working chamber 4 of the caisson 1. As an example, the compressor 15 may be a compressor provided as a backup in case of a power outage. In these cases, the compressor 15 located on-site can be effectively used to transport the backfill material M. As described above, in the backfill material filling device 10, the compressor 15 sends compressed air K to the ejector 14, thereby transporting the backfill material M inside the pipe 11 and supplying the backfill material M from the pipe 11 to the friction cut 6.

[0045] For example, the backfill material M is single-grain crushed stone. Single-grain crushed stone is crushed and sieved stone. As an example, the backfill material M is either No. 6 crushed stone or No. 7 crushed stone. In this case, adhesion of the backfill material M to the pipe 11 during transportation can be prevented, and the transportability of the backfill material M in the pipe 11 can be improved.

[0046] For example, the particle size of the backfill material M is 2.5 mm or more and 13 mm or less. As an example, the particle size of the backfill material M may be 5 mm or more and 13 mm or less. In this case, No. 6 crushed stone can be used as the backfill material M. Also, the particle size of the backfill material M may be 2.5 mm or more and 5 mm or less. In this case, No. 7 crushed stone can be used as the backfill material M.

[0047] Figure 6(a) is a schematic diagram showing an enlarged view of the outlet section 13. As shown in Figures 3 and 6(a), the outlet section 13 has, for example, a T-pipe 17, a valve 18, and a hose 19 that discharges backfill material M. For example, the pipe 11 includes a straight pipe 11b and the outlet section 13. The straight pipe 11b is, for example, a pipe other than the outlet section 13 of the pipe 11. The pipe 11 includes a plurality of straight pipes 11b, which are arranged along the sides of the caisson 1 in a plan view.

[0048] T-shaped pipe 17 is connected to, for example, straight pipe 11b via valve 20. T-shaped pipe 17 has, for example, first pipe section 17b connected to straight pipe 11b, second pipe section 17c connected to valve 20, and third pipe section 17d connected to valve 18. First pipe section 17b and second pipe section 17c are aligned on a straight line, and third pipe section 17d protrudes from first pipe section 17b and second pipe section 17c in a direction intersecting the straight line.

[0049] Valves 18 and 20 can be opened and closed. By opening valve 20, the backfill material M is transported inside pipe 11, and by closing valve 20, the transport of backfill material M inside pipe 11 is stopped. By opening valve 18, the backfill material M is transported to hose 19, and by closing valve 18, the transport of backfill material M to hose 19 is stopped.

[0050] The hose 19 is, for example, a flexible hose having flexibility. One example of the hose 19 is a suction hose. In this case, the hose 19 can be easily routed, the hose 19 can be lightweight, and the shape of the hose 19 can be maintained. However, the hose 19 may be, for example, a rubber hose, and the type of the hose 19 is not particularly limited. Furthermore, a hard pipe may be provided instead of the hose 19.

[0051] For example, the first outlet 13a, the second outlet 13b, the third outlet 13c, the fourth outlet 13d, the fifth outlet 13e, the sixth outlet 13f, the seventh outlet 13g, the eighth outlet 13h, the ninth outlet 13j, the tenth outlet 13k, the eleventh outlet 13m, the twelfth outlet 13n, the thirteenth outlet 13p, and the fourteenth outlet 13q have the same configuration. For example, each of the multiple outlets 13 has a valve 18 and a hose 19.

[0052] 6(b) is a diagram showing a corner of pipe 11 in a plan view. As shown in FIGS. 3 and 6(b), pipe 11 includes an L-shaped pipe 21. L-shaped pipe 21 is arranged at the corner of pipe 11 in a plan view. For example, one end of L-shaped pipe 21 is connected to a straight pipe 11b, and the other end of L-shaped pipe 21 is connected to a straight pipe 11b that extends in a different direction from straight pipe 11b.

[0053] For example, the L-shaped pipe 21 is curved. For example, the radius of curvature of the L-shaped pipe 21 is equal to or greater than a certain value. In this case, the curvature of the L-shaped pipe 21 can be made gentler, thereby reducing clogging of the backfill material M inside the L-shaped pipe 21. For example, the pipe 11 includes a plurality of L-shaped pipes 21. Each of the plurality of L-shaped pipes 21 is arranged, for example, outside the corner of the caisson 1 in a plan view.

[0054] Next, the backfilling material filling method according to this embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of the steps of the backfilling material filling method according to this embodiment. In this backfilling material filling method, backfilling material M is filled into the friction cut 6. As shown in Fig. 3, a pipe 11 for transporting backfilling material M is installed on the outer periphery 1b of the caisson 1 in a plan view (pipe installation step, step S1).

[0055] At this time, the pipes 11 are installed so that they surround the caisson 1 in a plan view and so that the multiple outlets 13 are lined up along the outer periphery 1b of the caisson 1 in a plan view. More specifically, multiple straight pipes 11b are arranged along one side of the caisson 1 in a plan view and connected to each other. An outlet 13 is connected to each straight pipe 11b. Then, an L-shaped pipe 21 is arranged at a position facing a corner of the caisson 1 in a plan view, and one end and the other end of the L-shaped pipe 21 are connected to the straight pipe 11b.

[0056] Next, an ejector 14 for transporting backfill material M is connected to one end of the pipe 11 (step of connecting an ejector, step S2). More specifically, an L-shaped pipe 21 and a straight pipe 11b are connected to one end of each of the two pipes 11, and the ejector 14 is connected to the end of the straight pipe 11b opposite to the L-shaped pipe 21. Then, a compressor 15 is connected to the ejector 14 via a pipe line 16 (step of connecting a compressor).

[0057] Meanwhile, separate from the installation of the pipe 11 and the connection of the ejector 14, the backfill material M is prepared (a step of preparing the backfill material). For example, the backfill material M stored in sandbags is prepared in advance, the sandbags are opened, and the backfill material M is poured into the vessel 12b, and the backfill material M is stored in the vessel 12b.

[0058] Thereafter, compressed air K is fed into the ejector 14 to transport the backfilling material M inside the pipe 11, and the backfilling material M is supplied from the pipe 11 to the friction cut 6 (step of supplying the backfilling material). For example, as shown in Figures 3 and 6(a), first, the valve 20 is opened, the valve 18 of the first outlet 13a is opened, and the valves 18 of the second outlet 13b (or all the outlets 13 other than the first outlet 13a) are closed (step S3).

[0059] Then, the backfilling material M is sucked by the ejector 14 (step S4). At this time, the compressor 15 sends compressed air K to the ejector 14 and inserts the suction pipe 14g into the backfilling material M, so that the ejector 14 transports the backfilling material M to the first outlet portion 13a.

[0060] Then, the backfilling material M is supplied from the first outlet portion 13a (step of supplying the backfilling material from the first outlet portion). At this time, the backfilling material M is supplied and filled into the friction cut 6 from the first outlet portion 13a (step S5). Then, when the supply of the backfilling material M from the first outlet portion 13a is completed, the valve 18 of the first outlet portion 13a is closed (step S6).

[0061] Next, it is determined whether or not the filling of the backfilling material M has been completed (step S7). For example, in the above example, only the filling of the backfilling material M from the first outlet 13a is performed, so the determination in step S7 is NO. If the determination in step S7 is NO, the process returns to step S3, and the valve 18 of the second outlet 13b is opened. At this time, all the valves 18 other than the valve 18 of the second outlet 13b are kept closed.

[0062] Then, in the same procedure as in the case of the first outlet portion 13a, the ejector 14 sucks in the backfilling material M (step S4), and the ejector 14 transports the backfilling material M to the second outlet portion 13b. Then, the backfilling material M is supplied from the second outlet portion 13b (step of supplying the backfilling material from the second outlet portion), and the backfilling material M is supplied and filled from the second outlet portion 13b into the friction cut 6 (step S5). When the supply of the backfilling material M from the second outlet portion 13b is completed, the valve 18 of the second outlet portion 13b is closed (step S6).

[0063] Then, it is determined whether or not the filling of the backfilling material M has been completed (step S7). For example, in the above example, since the filling of the backfilling material M has only been performed through the first outlet 13a and the second outlet 13b, it may be determined as NO in step S7, and the backfilling material M may be supplied to the third outlet 13c, the fourth outlet 13d, to the fourteenth outlet 13q in the same manner as above. However, it is not necessary to supply the backfilling material M to all of the first outlet 13a, the second outlet 13b, to the fourteenth outlet 13q, and the outlets 13 requiring the backfilling material M may be appropriately selected. Furthermore, the order in which the backfilling material M is supplied to the first outlet 13a, the second outlet 13b, to the fourteenth outlet 13q is not particularly limited.

[0064] When the filling of the backfilling material M into each part of the friction cut 6 is completed and the determination in step S7 is YES, for example, the pipe 11 is checked (step S8). Note that the checking of the pipe 11 does not have to be performed immediately after the filling of the backfilling material M, and may be performed some time after the filling of the backfilling material M.

[0065] When checking the pipe 11, it is checked whether or not the backfilling material M is clogging the L-shaped pipe 21 (a process of checking whether or not there is a clogging). Incidentally, examples of locations where the backfilling material M is likely to clog include the suction port of the ejector 14 and the L-shaped pipe 21. If a clog occurs at the suction port of the ejector 14, the clog may be cleared, for example, by shaking the ejector 14 by hand.

[0066] On the other hand, in the case of clogging of the L-shaped pipe 21, for example, after the backfilling material M has been supplied, it is confirmed whether or not the L-shaped pipe 21 is clogged with the backfilling material M. For example, it is possible to check whether or not the L-shaped pipe 21 is clogged with the backfilling material M by removing the L-shaped pipe 21 from the straight pipe 11b and looking inside the L-shaped pipe 21. It is also possible to check whether or not the L-shaped pipe 21 is clogged with the backfilling material M by checking the sound made when the L-shaped pipe 21 is struck. In this way, it is possible to check whether or not the L-shaped pipe 21 is clogged by various methods.

[0067] For example, if the backfilling material filling device 10 is used over a long period of time, the L-shaped pipe 21 may be worn due to a large amount of backfilling material M colliding with the inside of the L-shaped pipe 21. Therefore, when checking the pipe 11, it may be possible to check whether or not there is wear inside the L-shaped pipe 21. If damage occurs to the L-shaped pipe 21, the L-shaped pipe 21 may be replaced. The timing for checking the pipe 11 can be changed as appropriate. After going through the above steps, a series of steps in the backfilling material filling method is completed.

[0068] Next, the effects obtained from the backfilling material filling apparatus 10 and backfilling material filling method according to this embodiment will be described. In the backfilling material filling apparatus 10 and backfilling material filling method according to this embodiment, a pipe 11 for transporting backfilling material M is installed on the outer periphery 1b of the caisson 1 in a plan view. An ejector 14 for transporting the backfilling material M is connected to one end of the pipe 11. Compressed air K is then fed into the ejector 14, transporting the backfilling material M inside the pipe 11, and the backfilling material M is supplied from the pipe 11 to the friction cut 6. Thus, the backfilling material M is sucked into the ejector 14, which transports the backfilling material M, allowing the backfilling material M to be supplied to a predetermined location in the caisson 1, and the backfilling material M can be easily transported to locations distant from the ejector 14.

[0069] Therefore, even in a narrow site, the backfill material M can be easily transported by installing the pipe 11 on the outer periphery 1b of the caisson 1 in a plan view and having the ejector 14 transport the backfill material M through the pipe 11. Therefore, the backfill material M can be easily transported and filled into the friction cut 6 located on the outer periphery 1b of the caisson 1 in a plan view.

[0070] In this embodiment, the pipe 11 has a plurality of outlets 13 from which the backfill material M exits. In the backfill material filling method, in the step of installing the pipe 11, the pipe 11 may be installed so that the pipe 11 surrounds the caisson 1 in a plan view and the plurality of outlets 13 are lined up along the outer periphery 1b of the caisson 1 in a plan view. In this case, the pipe 11 that transports the backfill material M is arranged so that it surrounds the caisson 1 and the plurality of outlets 13 are lined up along the outer periphery 1b of the caisson 1 in a plan view. Therefore, the backfill material M can be supplied from each of the plurality of outlets 13 lined up along the circumferential direction of the caisson 1, and the backfill material M can be easily transported to the desired position in the caisson 1.

[0071] In this embodiment, the multiple outlets 13 include a first outlet 13a and a second outlet 13b located at a different position from the first outlet 13a. The first outlet 13a and the second outlet 13b each have a valve 18. The step of supplying the backfilling material M includes the steps of supplying the backfilling material M from the first outlet 13a by opening the valve 18 of the first outlet 13a and closing the valve 18 of the second outlet 13b, and supplying the backfilling material M from the second outlet 13b by closing the valve 18 of the first outlet 13a and opening the valve 18 of the second outlet 13b. In this case, the backfilling material M can be supplied sequentially from each of the first outlet 13a and the second outlet 13b, thereby efficiently transporting the backfilling material M to each section of the caisson 1.

[0072] In this embodiment, the backfill material M is single-grained crushed stone. In this case, since the backfill material M transported inside the pipe 11 is single-grained crushed stone, adhesion of the backfill material M to the inside of the pipe 11 can be reduced. Therefore, the transport of the backfill material M can be performed more efficiently.

[0073] In this embodiment, the particle size of the backfilling material M is 2.5 mm or more and 13 mm or less. In this case, since the particle size of the backfilling material M is 2.5 mm or more, adhesion of the backfilling material M to the inside of the pipe 11 can be reduced. Since the particle size of the backfilling material M is 13 mm or less, the transport of the backfilling material M by the ejector 14 can be performed more efficiently.

[0074] In this embodiment, the pipe 11 has an outlet 13, which is the portion where the backfilling material M comes out of the pipe 11, and the outlet 13 may include a hose 19 that discharges the backfilling material M. In this case, the hose 19 that discharges the backfilling material M is lightweight and can be moved freely, so that the filling of the backfilling material M can be carried out more efficiently.

[0075] In this embodiment, the pipe 11 includes an L-shaped pipe 21. The backfilling material filling method according to this embodiment includes a step of checking whether or not the L-shaped pipe 21 is clogged with the backfilling material M after the step of supplying the backfilling material M. Of the pipes 11 through which the backfilling material M passes, the L-shaped pipe 21 is a location where clogging with the backfilling material M is likely to occur. Therefore, by checking whether or not the L-shaped pipe 21 is clogged with the backfilling material M as described above, clogging with the backfilling material M during transportation can be prevented.

[0076] The above describes embodiments of the backfilling material filling method and backfilling material filling apparatus according to the present disclosure. However, the present disclosure is not limited to the above-described embodiments and may be modified within the scope of the gist described in the claims. In other words, the shape, size, number, material, and arrangement of each part of the backfilling material filling apparatus, as well as the content and order of the steps of the backfilling material filling method, may be modified as appropriate within the scope of the above-described gist.

[0077] For example, in the above-described embodiment, an example was described in which the pipe 11 includes a straight pipe 11b, an outlet portion 13, and an L-shaped pipe 21. However, the configuration of the pipe is not limited to this example, and for example, the pipe does not need to have an L-shaped pipe. In the above-described embodiment, an example was described in which the pipe 11 has multiple outlet portions 13. However, the number of outlet portions may be, for example, one, and is not particularly limited.

[0078] For example, in the above-described embodiment, the backfill material M is single-grained crushed stone, and the particle size of the backfill material M is 2.5 mm or more and 13 mm or less. However, the backfill material does not have to be single-grained crushed stone, and the particle size of the backfill material can also be changed as appropriate. [Explanation of symbols]

[0079] 1...caisson, 1b...periphery, 2...caisson body, 3b...cutting edge, 4...working chamber, 5...block, 6...friction cut, 7...lubricant injection device, 7b...pipeline, 10...backfilling material filling device, 11...pipe, 11b...straight piping, 12...material conveying device, 12b...vessel, 13...outlet portion, 13a...first outlet portion, 13b...second outlet portion, 13c...third outlet portion, 13d...fourth outlet portion, 13e...fifth outlet portion, 13f...sixth outlet portion, 13g...seventh outlet portion, 13h...eighth outlet portion, 13j...ninth outlet portion, 13k...tenth outlet portion, 13m...11th outlet section, 13n...12th outlet section, 13p...13th outlet section, 13q...14th outlet section, 14...ejector, 14b...inlet pipe, 14c...branch pipe, 14d...junction pipe, 14f...conveyor pipe, 14g...suction pipe, 15...compressor, 16...pipeline, 17...T-shaped pipe, 17b...first pipe section, 17c...second pipe section, 17d...third pipe section, 18...valve, 19...hose, 20...valve, 21...L-shaped pipe, D1...first direction, D2...second direction, G...ground, K...compressed air, L...slip material, M...backfill material, P...part, S...ground surface.

Claims

1. A backfilling material filling method for filling a friction cut with backfilling material to reduce peripheral friction that occurs in a caisson when the caisson is sunk into the ground, A step of installing a pipe for transporting the backfill material around the outer periphery of the caisson in a plan view; connecting an ejector for transporting the backfill material to one end of the pipe; a step of conveying the backfill material inside the pipe by supplying compressed air to the ejector and supplying the backfill material from the pipe to the friction cut; Equipped with Backfill material filling method.

2. the pipe has a plurality of outlets at which the backfill material exits the pipe; A backfilling material filling method as described in claim 1, wherein in the process of installing the pipe, the pipe is installed so that the pipe surrounds the caisson in a plan view and so that multiple outlet portions are lined up along the outer periphery of the caisson in a plan view.

3. the plurality of outlets include a first outlet and a second outlet disposed at a position different from the first outlet, the first outlet and the second outlet have valves; The step of providing backfill material includes: dispensing the backfill material from the first outlet by opening the valve at the first outlet and closing the valve at the second outlet; dispensing the backfill material from the second outlet by closing the valve at the first outlet and opening the valve at the second outlet; Including, The backfilling material filling method according to claim 2.

4. The backfill material is single-grain crushed stone. The method for filling a backfill material according to claim 1 or 2.

5. The particle size of the backfill material is 2.5 mm or more and 13 mm or less; The backfilling material filling method according to claim 4.

6. the pipe has an outlet portion where the backfill material exits the pipe; The outlet portion includes a hose that discharges the backfill material. The method for filling a backfill material according to claim 1 or 2.

7. the tube includes an elbow; a step of checking whether or not the backfilling material is clogged in the L-shaped pipe after the step of supplying the backfilling material; The method for filling a backfill material according to claim 1 or 2.

8. A backfilling material filling device that fills backfilling material into a friction cut that reduces peripheral friction generated in the caisson when the caisson is sunk into the ground, A pipe installed on the outer periphery of the caisson in a plan view; an ejector connected to one end of the pipe; a compressor that supplies compressed air to the ejector; Equipped with The compressor feeds compressed air into the ejector to transport the backfill material inside the pipe, and supplies the backfill material from the pipe to the friction cut. Backfill material filling equipment.

Images