Hoisting structure used in slim caisson method and slim caisson method

Abstract

To improve working efficiency in a hoisting work.SOLUTION: A hoisting structure used in a slim caisson method includes: a fixed part 30 which is fixed to a suspension engagement part 21 provided on an outer peripheral surface 20a of a caisson shaft 20; a first traveling rail 50 which is supported on the fixed part 30 and extends in a circumferential direction X1 outside the caisson shaft 20; a lower structure 60 which is guided to the first traveling rail 50 and is rotatable in the circumferential direction X1; a second traveling rail 70 which is provided on the lower structure 60 and extends in a radial direction X2 approaching / separating from the caisson shaft 20; and a hoisting device 80 which is guided to the second traveling rail 70 and is movable.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a lifting structure used in a slim caisson construction method and a slim caisson construction method. [Background technology]

[0002] Conventionally, a known pneumatic caisson construction method for constructing bridge foundations and shafts is the so-called "slim caisson construction method," which can be applied to restricted areas such as when constructing a caisson close to other structures or in narrow areas. In a typical pneumatic caisson construction method, a material lock, which is the lifting equipment for the earth removal bucket, and a man lock, which is the lifting equipment for workers, are installed separately (see, for example, Patent Document 1). In contrast, the slim caisson method uses a shaft specifically for slim caissons that combines material lock and manlock, making it possible to construct circular caissons on small surfaces, such as φ7.0m or less. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-187218 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the conventional slim caisson method, because the framework (bridge foundations and shafts) is constructed in narrow spaces, construction can be affected by headroom restrictions. Under such headroom restrictions, there are cases where it is difficult to lift loads using a crane during slim caisson construction. In such cases, rebar assembly is carried out manually, but when the main rebar is a large-diameter rebar such as D51, there are restrictions on handling heavy objects. As a result, multiple people must manually carry and assemble each rebar, which reduces work efficiency and leaves room for improvement.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a lifting structure used in the slim caisson construction method and a slim caisson construction method that can improve work efficiency in lifting operations. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the lifting structure used in the slim caisson construction method of the present invention is a lifting structure used in the slim caisson construction method that uses a hanging engagement portion provided on the outer surface of the caisson shaft, enabling lifting around the caisson shaft, and is characterized by comprising a fixed portion fixed to the hanging engagement portion, a first running rail supported by the fixed portion and extending in a first circumferential direction on the outside of the caisson shaft, a lower structure that is guided by the first running rail and can rotate in the circumferential direction, a second running rail provided on the lower structure and extending in a second direction approaching and moving away from the caisson shaft, and a lifting device that is guided by the second running rail and can move.

[0007] In addition, the slim caisson construction method of the present invention is a slim caisson construction method that uses the lifting structure used in the slim caisson construction method described above to construct a caisson, and is characterized by having the steps of attaching the lifting structure to the hanging engagement portion provided on the outer surface of the caisson shaft, and moving the lifting device within a lifting work range in which the lifting device can move the first running rail and the second running rail to perform lifting work related to the construction of the caisson.

[0008] In this invention, the fixed part is fixed using a hanging locking part previously provided on the outer periphery of the caisson shaft, and the first running rail, lower structure, and second running rail are provided on this fixed part, so that the lifting device moves the first running rail and the second running rail within the movable lifting work range to perform the lifting work, thereby improving the work efficiency in constructing the caisson. In particular, in this invention, because the lifting structure is supported by the caisson shaft, even if, for example, an existing structure is installed close to the caisson shaft and there are construction conditions for headroom restrictions around the caisson shaft, by locating the lifting structure in the caisson shaft at a low position, the lifting work of construction materials and heavy objects can be easily performed using the lifting device, thereby reducing the number of workers and improving work efficiency.

[0009] In addition, in the lifting structure used in the slim caisson construction method of the present invention, it is preferable that the fixed portion is divided into two parts so that it can clamp the hanging engaging portion, and that it is engaged by an engaging means while clamping the hanging engaging portion.

[0010] In the present invention, the fixing portion can be attached to the outer surface of the caisson shaft by the simple process of clamping the hanging engagement portion between the two divided fixing portions and engaging them with the engaging means.

[0011] In addition, it is preferable that the lifting structure used in the slim caisson construction method of the present invention is supported by the fixed portion and has an overhang portion extending radially outward from the fixed portion.

[0012] In this case, the first traveling rail extending in the circumferential direction can be attached at a position spaced from the fixed part by the extension length of the extension part, which reduces the moment of lifting acting on the second traveling rail extending outward from the lower structure, and increases the extension length of the second traveling rail from the caisson shaft, thereby widening the lifting range. [Effects of the Invention]

[0013] According to the lifting structure used in the slim caisson construction method of the present invention and the slim caisson construction method, the work efficiency in lifting work can be improved. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a vertical cross-sectional view showing the construction state of a slim caisson construction method according to an embodiment of the present invention. [Figure 2] This is an exploded oblique view showing the state in which the fixing part is fixed to the hanging engagement part of the caisson shaft. [Figure 3] FIG. 2 is a perspective view showing the configuration of the lifting structure of FIG. 1. [Figure 4] FIG. 4 is a plan view of the lifting structure shown in FIG. 3 as seen from above. [Figure 5] This is an oblique view showing the state in which the fixing part is fixed to the caisson shaft. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, the lifting structure used in the slim caisson construction method and the slim caisson construction method according to an embodiment of the present invention will be described with reference to the drawings.

[0016] As shown in Figure 1, the lifting structure 1 used in the slim caisson construction method of this embodiment uses a hanging engagement portion 21 (see Figure 2) provided on the outer peripheral surface 20a of the caisson shaft 20, making it possible to lift the periphery of the caisson shaft 20. The lifting structure 1 of this embodiment is applied to a caisson 10 in the slim caisson construction method, which is a pneumatic caisson construction method adapted to a caisson with small planar dimensions as shown in Figure 1.

[0017] Here, an existing structure 100 is adjacent to the periphery of the body of the caisson 10 of this embodiment. That is, in this embodiment, the caisson 10 is close to a foundation 101 provided on the ground of the existing structure 100, and is constructed between a pair of adjacent foundations 101. Note that the shape and configuration of the existing structure 100 are not limited to this embodiment and can be modified as appropriate.

[0018] In the slim caisson construction method of this embodiment, a single dedicated caisson shaft 20 is installed that integrates material locks (lifting equipment for the earth removal bucket) and manlocks (lifting equipment for workers), and the side wall portion 12 of the caisson 10 is constructed around the caisson shaft 20. The caisson shaft 20 has a larger outer diameter than general material locks and manlocks.

[0019] The caisson 10 has a bottom 11 provided at the lower end and having a circular shape in a plan view, and a cylindrical side wall 12 provided on the bottom 11 and extending in the vertical direction. The bottom 11 has a plate-like slab 13 that is installed horizontally and a cutting edge 14 that protrudes downward from the outer periphery of the slab 13. Below the slab 13 is a work chamber 15 where excavation work is carried out. A dedicated excavator 16 is installed on the underside of the slab 13 to excavate the ground inside the work chamber 15 and remove soil.

[0020] The side wall portion 12 is provided on the outer edge portion of the bottom portion 11. The side wall portion 12 is constructed successively from bottom to top as the caisson 10 sinks. In FIG. 1, the side wall portion 12 that has already been constructed is indicated by the symbol "12A," and the area where the new side wall portion 12 will be constructed is indicated by the symbol "12B." The side wall portion 12 is made of reinforced concrete. In this embodiment, the side wall portion 12 is constructed by pouring concrete on-site.

[0021] The caisson shaft 20 is cylindrical (see Figure 3). The caisson shaft 20 is installed on the bottom 11 so as to extend in the vertical direction. Access between the interior of the caisson shaft 20 and the work chamber 15 is possible via holes (not shown) provided in the slab 13. As shown in Figure 1, a work scaffold 22 is provided at the upper end of the caisson shaft 20. The work scaffold 22 has a rectangular work table in a plan view and handrails fixed around the work table.

[0022] Here, in the caisson shaft 20 and the lifting structure 1, the central axis of the caisson shaft 20 is called the shaft axis O, the direction along the shaft axis O is called the vertical direction, the direction that intersects the shaft axis O when viewed from the vertical direction is called the radial direction X2, and the direction that circles around the shaft axis O is called the circumferential direction X1.

[0023] As shown in Figures 2 and 3, a plurality (four) of hanging engagement parts 21 are attached to the upper part of the outer peripheral surface 20a of the caisson shaft 20 at regular intervals in the circumferential direction X1 (here, at 90-degree intervals in the circumferential direction X1). The hanging engagement parts 21 are plate-shaped members that protrude radially outward from the caisson shaft 20, and are brackets with their plate surfaces oriented parallel to the shaft axial direction. The hanging engagement parts 21 have bolt holes 21a formed through the plate surface. This lifting engagement portion 21 is a portion that is provided in advance on the caisson shaft 20 to engage and lift the crane hook 102 (see Figure 1) when the caisson shaft 20 is successively lifted during construction of the caisson 10 (see Figure 1) or when it is removed.

[0024] Next, the configuration of the lifting structure 1 supported on the outer peripheral surface 20a of the caisson shaft 20 will be specifically described with reference to FIGS. The lifting structure 1 includes a fixed portion 30, a protruding portion 40, a first traveling rail 50, a lower structure 60, a second traveling rail 70, and a lifting device 80.

[0025] 2, 3, and 5, the fixing portions 30 are fixed to the four hanging engaging portions 21. In other words, the four fixing portions 30 are fixed to the outer peripheral surface 20a of the caisson shaft 20. The fixing part 30 is composed of a pair of fixing pieces 30A, 30B with an L-shaped cross section that are split into two halves so that the hanging locking part 21 can be sandwiched between them, and is engaged by engaging means (bolt 31 and nut 32 shown in FIG. 2) while sandwiching the hanging locking part 21. A bolt hole 30a is formed in one first piece 30c of each of the fixing pieces 30A, 30B. The fixing part 30 is arranged so that the other second piece 30d faces radially outward, and is fixed to the hanging locking part 21 by sandwiching the hanging locking part 21 between the pair of fixing pieces 30A, 30B and inserting the bolt 31 through the bolt hole 30a and the bolt hole 21a of the hanging locking part 21 and tightening it with the nut 32.

[0026] As shown in Figures 3 and 4, the protruding portion 40 is supported by the fixed portion 30 and extends outward from the fixed portion 30 in the radial direction X2. In this embodiment, an H-shaped steel is used for the protruding portion 40, and the material axis direction is arranged parallel to the radial direction X2. A first end 40a of the protruding portion 40 on the inner side in the radial direction X2 is fixed to the second piece 30d of the fixed pieces 30A, 30B by a fixing means such as a bolt. The protruding length of the protruding portion 40 is set to match the diameter dimension of the first traveling rail 50.

[0027] The first traveling rail 50 is supported by the lower end of the second end 40b, which is on the outer side in the radial direction X2, of the overhanging portion 40, which is fixed to fixing portions 30 provided at four locations in the circumferential direction X1. The first traveling rail 50 is an I-beam and has a ring shape that extends endlessly around the entire circumference in the circumferential direction X1 (first direction) on the outside of the caisson shaft 20. The first traveling rail 50 is provided coaxially with the shaft axis O of the caisson shaft 20.

[0028] The lower structure 60 is guided by the first traveling rail 50 and is rotatable in the circumferential direction X1. The lower structure 60 is framed by vertical beams 61A and horizontal beams 61B to have a rectangular outer shape in plan view. A pair of intermediate beams 61C extending parallel to the vertical beams 61A is provided inside the framed vertical beams 61A and horizontal beams 61B. The interior surrounded by the pair of horizontal beams 61B and the pair of intermediate beams 61C has an opening 60a through which the caisson shaft 20 can pass in the vertical direction. As shown in FIG. 3 , a plurality of trolleys 62 that slide along the first traveling rail 50 are provided on the upper surface of the lower structure 60. The trolleys 62 have guide rollers 62a that sandwich the lower flange of the first traveling rail 50 from above and below. The lower structure 60 is supported in a suspended state by the plurality of trolleys 62. The lower structure 60 configured in this manner rotates in the circumferential direction X1 on the outer periphery of the caisson shaft 20.

[0029] As shown in FIGS. 3 and 4 , the second traveling rail 70 is an I-beam that is provided below the lower structure 60 and extends in a second direction (the radial direction X2 in this embodiment) toward and away from the caisson shaft 20. A base end 70a of the second traveling rail 70 on the caisson shaft 20 side is fixed to the longitudinal center of one of the intermediate beams 61C of the lower structure 60, and a tip end 70b is provided with a length that extends outward from the lower structure 60. As shown in FIG. 1 , the tip end 70b of the second traveling rail 70 is positioned so that the lifting device 80 can reach the outer periphery of the side wall 12 of the caisson 10, at least in a plan view. Because the second traveling rail 70 is located below the lower structure 60, the lifting device 80 does not interfere with the ring-shaped first traveling rail 50.

[0030] The lifting device 80 includes a trolley 81 that can move back and forth while being guided by the second traveling rail 70, and an electric hoist 82 that is supported by the trolley 81. As shown in Figure 3, the trolley 81 has guide rollers 81a that sandwich the lower flange of the second traveling rail 70 from above and below. As shown in Figure 4, the lifting device 80 is provided so as to be freely movable, covering almost the entire area directly above the body of the caisson 10, by rotating in the circumferential direction X1 with the lower structure 60 guided by the first traveling rail 50, and by linear movement in the radial direction X2 with the lower structure 60 guided by the second traveling rail 70. In the lifting structure 1, the area in which the second traveling rail 70 rotates in the circumferential direction X1 is the movable area of ​​the lifting device 80, i.e., the lifting operation range.

[0031] Next, the operation of the lifting structure 1 used in the slim caisson construction method and the slim caisson construction method will be described in detail with reference to Figs. The lifting structure 1 used in the slim caisson construction method according to this embodiment uses a hanging engaging portion 21 provided on the outer peripheral surface 20a of the caisson shaft 20, making it possible to lift the periphery of the caisson shaft 20. The lifting structure 1 used in the slim caisson construction method comprises a fixed portion 30 fixed to the hanging engaging portion 21, a first traveling rail 50 supported by the fixed portion 30 and extending in the circumferential direction X1 on the outside of the caisson shaft 20, a lower structure 60 guided by the first traveling rail 50 and rotatable in the circumferential direction X1, a second traveling rail 70 provided on the lower structure 60 and extending in the radial direction X2 approaching and moving away from the caisson shaft 20, and a lifting device 80 guided by the second traveling rail 70 and movable.

[0032] In addition, the slim caisson construction method according to this embodiment includes a step of attaching the lifting structure 1 to the hanging engagement portion 21 provided on the outer surface 20a of the caisson shaft 20, and a step of moving the lifting device 80 within a lifting operation range in which the lifting device 80 can move on the first running rail 50 and the second running rail 70 to perform lifting work related to the construction of the caisson 10.

[0033] In this embodiment, the fixed part 30 is fixed using the hanging engaging part 21 provided in advance on the outer peripheral surface 20a of the caisson shaft 20, and the first traveling rail 50, the lower structure 60, and the second traveling rail 70 are provided on the fixed part 30. This allows the lifting device 80 to move the first traveling rail 50 and the second traveling rail 70 within their movable lifting range to perform lifting work, thereby improving work efficiency in constructing the caisson 10. In particular, in this embodiment, because the lifting structure 1 is supported by the caisson shaft 20, even if, for example, an existing structure 100 is installed close to the caisson shaft 20 and there is a construction condition that requires headroom around the caisson shaft 20, by positioning the lifting structure 1 in the caisson shaft 20 at a low position, the lifting work of construction materials and heavy objects can be easily performed using the lifting device 80, including the headroom-restricted area R (the colored area shown in FIG. 1 ), thereby reducing the number of workers and improving work efficiency.

[0034] In this embodiment, the fixing portion 30 is configured to be divided into two parts so that the hanging engaging portion 21 can be sandwiched between them, and is engaged with the bolt 31 and nut 32 in a state where the hanging engaging portion 21 is sandwiched between them. By configuring it in this manner, the fixing part 30 can be attached to the outer surface of the caisson shaft 20 by the simple process of clamping the hanging engagement part 21 between the fixing pieces 30A and 30B of the two-part fixing part 30 and engaging them with bolts 31 and nuts 32.

[0035] In this embodiment, a protruding portion 40 is provided which is supported by the fixed portion 30 and extends radially outward from the fixed portion 30 . With this configuration, the first traveling rail 50 extending in the circumferential direction X1 can be attached at a position spaced apart from the fixed part 30 by the extension length of the extension part 40. As a result, the moment due to lifting acting on the second traveling rail 70 extending outward from the lower structure 60 can be kept small, and the extension length of the second traveling rail 70 from the caisson shaft 20 can be increased, thereby widening the lifting operation range.

[0036] As described above, the lifting structure 1 used in the slim caisson construction method according to this embodiment and the slim caisson construction method can improve the work efficiency in lifting work.

[0037] The above describes the lifting structure used in the slim caisson construction method and the embodiments of the slim caisson construction method according to the present invention, but the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of its intent.

[0038] For example, the shape and dimensions of the caisson shaft 20 in the above embodiment can be set to a shape and dimensions that match the conditions of the body of the caisson 10 to be constructed. Therefore, the above embodiment is merely an example, and the shape, dimensions, quantity, and other configurations of each part of the lifting structure 1 (fixed part 30, overhanging part 40, first traveling rail 50, lower structure 60, second traveling rail 70, and lifting device 80) can be changed as appropriate. Furthermore, in this embodiment, the overhanging portion 40 is provided between the fixed portion 30 and the first traveling rail 50, but the overhanging portion 40 may be omitted.

[0039] In addition, in this embodiment, the second traveling rail 70 and the lifting device 80 are each provided individually, but a configuration may be adopted in which a plurality of second traveling rails 70 and lifting devices 80 are provided. For example, by providing a second traveling rail 70 from each of a pair of intermediate beams 61C of the lower structure 60, it is possible to perform lifting operations on both sides of the caisson shaft 20.

[0040] Furthermore, in this embodiment, four hanging locking portions 21 are provided on the outer peripheral surface 20a of the caisson shaft 20 in the circumferential direction X1, but this number can be changed as appropriate. Also, it is not necessary to fix the fixing portions 30 to all of the hanging locking portions 21; for example, if there are eight hanging locking portions 21, the fixing portions 30 may be fixed to four of the eight.

[0041] Furthermore, the fixing part 30 is configured to be divided into two parts so that it can clamp the hanging locking part 21, and is configured to be engaged by an engaging means in a state in which the hanging locking part 21 is clamped, but is not limited to such a configuration of the fixing part 30. For example, instead of being divided into two parts, it is also possible to adopt a configuration in which the fixing part has a recess for engaging the hanging locking part 21, and the hanging locking part 21 is engaged in the recess and fixed with a bolt or the like.

[0042] In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0043] 1 Lifting structure 10 Caisson 12 Side wall 20 Caisson shaft 20a Outer surface 21 Hanging latch 30 Fixed part 30A, 30B fixed piece 31 Bolt (engagement means) 32 Nut (engagement means) 40 overhang 50 First running rail 60 Undercarriage 70 Second running rail 80 Lifting equipment 100 Existing structures X1 Circumferential direction (1st direction) X2 Radial direction (second direction)

Claims

1. A lifting structure used in a slim caisson construction method that uses a hanging locking portion provided on the outer peripheral surface of the caisson shaft to enable lifting around the caisson shaft, a fixing portion fixed to the hanging engaging portion; A first traveling rail supported by the fixed portion and extending in a first circumferential direction on the outside of the caisson shaft; a lower structure that is guided by the first traveling rail and is rotatable in the circumferential direction; A second traveling rail provided on the lower structure and extending in a second direction approaching and moving away from the caisson shaft; a lifting device that is movable while being guided by the second traveling rail; A lifting structure used in the slim caisson construction method.

2. A lifting structure used in the slim caisson construction method described in claim 1, wherein the fixing portion is divided into two parts so that it can clamp the hanging engagement portion, and is engaged by an engagement means while clamping the hanging engagement portion.

3. A lifting structure used in the slim caisson construction method described in claim 1, wherein a protruding portion is supported by the fixed portion and extends radially outward from the fixed portion.

4. A slim caisson construction method using the lifting structure used in the slim caisson construction method according to any one of claims 1 to 3, Attaching the lifting structure to the hanging engaging portion provided on the outer circumferential surface of the caisson shaft; A step of moving the lifting device within a lifting operation range in which the lifting device can move the first traveling rail and the second traveling rail, thereby performing lifting work related to the construction of the caisson; Slim caisson construction method.

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