Method for constructing an automotive pit

Abstract

To provide a construction method of a pit for a vehicle further reduced in a construction period.SOLUTION: A construction method of a pit for a vehicle formed under a floor face of a pit construction site for inspection or maintenance of the vehicle comprises: a manufacturing step of manufacturing in a factory a concrete molding having a pair of side parts and a bottom part with an open upper part; a transporting step of transporting the concrete molding manufactured in the manufacturing step from the factory to the pit construction site; an excavating step of forming a recessed part for placing the concrete molding by excavating the floor face; and a placing step of placing the concrete molding in the recessed part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for constructing a pit for automobiles.

Background Art

[0002] In an automobile maintenance factory, in order to inspect or maintain the bottom part of an automobile, a pit is constructed by excavating the floor surface, and a lift device for lifting the vehicle from the floor surface and various inspection devices are installed in this pit. Conventionally, the method for constructing a pit for automobiles is as follows: First, the floor surface of the maintenance factory is excavated to form a recess, a formwork is assembled in this recess, reinforcing bars or the like are arranged in the space partitioned by this formwork, concrete is placed, and after the placed concrete is cured, the formwork is removed.

[0003] Such a conventional construction method requires a lot of time for the construction of a formwork for forming a concrete placement space in the recess formed on the floor surface and for curing the placed concrete. Therefore, in Patent Document 1, a pit construction method that can further shorten the construction period has been proposed. In this pit construction method, the formwork is fabricated at a location different from the floor surface where the pit is to be constructed. This formwork has a scaffold at the bottom and is arranged so as to have a concrete placement space between the side surface and the bottom surface of the recess when placed in the recess. Therefore, in a single concrete placement process, the entire pit including the side and bottom parts of the pit can be formed, and during the concrete curing period, the work of installing devices inside the formwork is carried out, and the formwork is left buried as it is. Therefore, compared with the conventional construction method, the on-site formwork assembly work and removal work can be eliminated, and thus the construction period can be shortened.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] However, the pit construction method described in Patent Document 1 still includes a concrete curing period during the construction period, and therefore cannot drastically shorten the construction period, and further reductions in construction time are desired.

[0006] This disclosure is made in view of the circumstances described above, and aims to further shorten the construction period in a method for constructing automobile pits. [Means for solving the problem]

[0007] To achieve the above objective, one embodiment of the method for constructing an automobile pit according to the present disclosure is a method for constructing an automobile pit formed beneath the floor surface of a pit construction site for inspecting or maintaining an automobile, comprising: a manufacturing step of manufacturing a concrete molded body having a pair of sides and a bottom and an open top in a factory; a transport step of transporting the concrete molded body manufactured in the manufacturing step from the factory to the pit construction site; an excavation step of excavating the floor surface to form a recess on which the concrete molded body can be placed; and a placement step of placing the concrete molded body in the recess. [Effects of the Invention]

[0008] According to one embodiment of the method for constructing an automobile pit described herein, the construction period at the site where the automobile pit is constructed can be significantly shortened, and since multiple concrete molded bodies can be manufactured using the same formwork at the factory that manufactures the formwork, the quality of the concrete molded bodies can be standardized and manufacturing costs can be reduced. [Brief explanation of the drawing]

[0009] [Figure 1] This is a process diagram showing a method for constructing an automobile pit according to one embodiment. [Figure 2] This is a process diagram showing the excavation process according to one embodiment of a pit construction method. [Figure 3]This is a perspective view showing an example of a concrete molded product manufactured during the manufacturing process. [Figure 4] This is a plan view diagram illustrating the marking-out step in the excavation process, showing lines drawn on the floor surface where the automobile pit will be constructed to define the excavation location. [Figure 5] This is a perspective view showing the concrete molded body placed in the recess through the placement process. [Figure 6] This perspective view shows the completed state of the automobile pit after the placement process, where the gap formed between the concrete molded body and the recess has been filled. [Figure 7] This is a perspective view showing a placement process according to one embodiment, which is carried out by a lifting device. [Modes for carrying out the invention]

[0010] Hereinafter, several embodiments of the present invention will be described with reference to the attached drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in or shown in these embodiments are not intended to limit the scope of the present invention, but are merely illustrative examples. For example, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" should not only strictly describe such arrangements, but also describe states of relative displacement with tolerances or angles or distances that allow for the same function to be achieved. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. For example, expressions describing shapes such as squares or cylinders shall not only represent geometrically precise shapes such as squares or cylinders, but also shapes that include protrusions, chamfers, etc., to the extent that the same effect can be achieved. On the other hand, expressions such as "to possess," "to be equipped with," "to have," "to include," or "to have" a single component are not exclusive expressions that exclude the existence of other components.

[0011] Figure 1 is a process diagram showing a method for constructing an automobile pit according to one embodiment. Figure 2 is a process diagram showing an excavation process according to one embodiment of the pit construction method. In Figure 1, first, a concrete molded body that defines the shape of the automobile pit is manufactured (manufacturing process S10). The automobile pit is formed, for example, under the floor inside a repair shop where vehicles are inspected or maintained. On the other hand, the concrete molded body is manufactured at a location different from the site where the pit is constructed. For example, it is manufactured at a factory for manufacturing concrete molded bodies, and this factory may be located at a distance from the repair shop where the automobile pit is constructed, or it may be located adjacent to the repair shop. The concrete molded body manufactured at the manufacturing plant is transported to the pit construction site by means of transport such as a truck (transportation process S11).

[0012] Figure 3 is a perspective view showing an example of a concrete molded body 10 manufactured in manufacturing process S10. The concrete molded body 10 shown in Figure 3 is composed of a base 12 and a pair of orthogonal parts 14A and 14B connected at both longitudinal ends of the base 12 in a direction perpendicular to the base 12, and is formed in a U-shape overall. The base 12 and the pair of orthogonal parts 14A and 14B each have a pair of side parts 16a and 16b that form a pair of sides of the automobile pit, and a bottom part 18 that forms the bottom surface of the automobile pit. Inside the pair of side parts 16a and 16b and the bottom part 18 there are inner spaces S1, S2 or S3 with their tops open. These inner spaces form the space created by the automobile pit below the floor surface.

[0013] In the embodiment shown in FIG. 3, the concrete molded body 10 is formed by being divided into a base portion 12 and a pair of orthogonal portions 14A and 14B. When the concrete molded body 10 is large and has a complex shape as shown in FIG. 3, it is usually manufactured by being divided into appropriate sizes so as to be easily transported by a truck or the like.

[0014] In FIG. 3, the outer shapes of each of the base portion 12 and the orthogonal portions 14A and 14B have the shape of a rectangular parallelepiped. At both longitudinal ends of the base portion 12, on the side walls where the orthogonal portions 14A and 14B abut, openings O1 are formed for communicating the inner space S1 formed in the base portion 12 with the inner spaces S2 and S3 formed in each of the orthogonal portions 14A and 14B. On the other hand, on the side walls at one longitudinal end side of each of the orthogonal portions 14A and 14B, after being placed in the recess 24, openings O2 and O3 are formed for communicating the inner space S1 formed in the base portion 12 with the inner spaces S2 and S3 formed in the orthogonal portions 14A and 14B.

[0015] By forming the concrete molded body 10 by dividing it in this way, the concrete molded body 10 manufactured in a dedicated factory can be dispersed and transported on a plurality of trucks, facilitating transportation. Also, when placing the concrete molded body 10 in the recess 24 at the site where the pit 1 is constructed, there is an advantage that the weight of the lifting object can be reduced. Furthermore, since each of the base portion 12 and the orthogonal portions 14A and 14B is formed in the shape of a rectangular parallelepiped according to the shape of the truck bed, it is easy to load onto the truck bed.

[0016] The width dimension W1 of the inner space S1 formed in the base portion 12, the width dimension W2 of the inner space S2 formed in the orthogonal portion 14A, and the width dimension W3 of the inner space S3 formed in the orthogonal portion 14B are set to be smaller than the interval between the tires of the vehicle so that a vehicle to be inspected or maintained can be arranged to cover one of these inner spaces above the pit. The concrete molded body 10 shown in FIG. 3 is only an example, and the concrete molded body is not limited to this shape.

[0017] In the manufacturing process S10, steps such as fabricating a formwork that forms a placement space where flowing concrete is placed, a reinforcement placement step of arranging reinforcing bars in the placement space, a placement step of pouring concrete into the placement space, and a demolding step of demolding the solidified concrete molded body 10 after curing from the formwork are appropriately carried out after the concrete placed in the placement space has cured. In a manufacturing factory, through these steps, the concrete molded body 10 is manufactured. [[ID=,2]]

[0018] Separate from the manufacturing process S10, at the site where an automobile pit is constructed, an excavation process S12 is performed in which the floor surface is excavated to form a recess where the concrete molded body 10 can be placed. FIG. 2 shows each step performed in the excavation process S12 according to an embodiment.

[0019] In the excavation process S12 illustrated in FIG. 2, first, an excavation line that defines the position to be excavated is drawn on the floor surface where the pit is to be constructed (marking step S12a). FIG. 4 is a plan explanatory view showing a state in which an excavation line 22 that defines the position to be excavated is drawn on the floor surface 20 where an automobile pit is to be constructed in the marking step S12a. Next, using a cutter device, the concrete layer forming the floor surface 20 is cut along the excavation line 22 (cutter insertion step S12b). Then, the cut concrete layer is removed, and the soil layer below this concrete layer is excavated to form a recess 24 where the concrete molded body 10 is to be placed (recess formation step S12c). As shown in FIG. 4, a recess 24 where the concrete molded body 10 is to be placed is formed inside the excavation line 22.

[0020] After forming the recess 24 in the excavation process S12, the concrete molded body 10 is placed in the recess 24 (placement step S14). For example, the concrete molded body 10 is loaded onto a truck or the like and transported from the manufacturing factory to the site where the automobile pit is to be constructed. Then, the concrete molded body 10 is unloaded from the truck, carried to the site where the pit is to be constructed, and placed in the recess 24

[0021] Figure 5 is a perspective view showing the state in which the concrete molded body 10 has been placed in the recess 24 formed in the floor surface 20 by the placement process S14. In Figure 5, a gap c is formed between the concrete molded body 10 and the wall surfaces (side wall surface 24a and bottom wall surface 24b) that form the recess 24. Figure 6 is a perspective view showing the state in which the construction of the automobile pit 1 has been completed by filling the gap c formed between the concrete molded body 10 and the recess 24 after the concrete molded body 10 has been placed in the recess 24.

[0022] According to this embodiment, the concrete molded body 10 can be manufactured in advance at a location separate from the site where the pit 1 is constructed, for example, at a dedicated manufacturing plant, thus eliminating the concrete curing period at the construction site of the pit 1. Furthermore, because the concrete molded body 10 is manufactured at a separate location, the assembly of formwork to form the concrete pouring space at the construction site of the pit 1 can also be omitted. As a result, the construction period at the construction site of the pit 1 can be significantly shortened. In addition, since multiple concrete molded bodies 10 can be manufactured using a single steel formwork at a dedicated factory that manufactures the concrete molded bodies 10, the quality of the concrete molded bodies 10 can be standardized, and the manufacturing cost of each concrete molded body 10 can be reduced. Moreover, there is the advantage of significantly reducing construction waste such as wooden formwork that was conventionally used at the construction site of the pit 1.

[0023] In one embodiment, in the placement step S14, after the concrete molded body 10 is placed in the recess 24, grout material is injected into the gap c (see Figure 5) formed between the concrete molded body 10 and the wall surface forming the recess 24 (for example, the side wall surface 24a and bottom wall surface 24b shown in Figure 5) to fill the gap c (grout injection step S16 shown in Figure 1). In Figure 6, reference numeral 30 indicates the grout material injected between the concrete molded body 10 and the wall surface forming the recess 24. As the material for the grout material, for example, cement-based materials, glass-based materials, synthetic resins, etc., can be used.

[0024] Thus, after the placement step S14 in which the concrete molded body 10 is placed in the recess 24, a grout injection step S16 is performed to inject grout material 30 between the concrete molded body 10 and the wall surface forming the recess 24. This improves the adhesion between the concrete molded body 10 and the wall surface forming the recess 24 surrounding the concrete molded body 10, thereby preventing moisture such as rainwater from penetrating between them. Furthermore, since the grout material 30 has good durability and does not shrink, it can stably support the concrete molded body 10 placed in the recess 24, preventing the concrete molded body 10 from settling. In addition, when injecting grout material between the lower surface of the bottom 18 of the concrete molded body 10 and the bottom wall surface 24b forming the recess 24, leveling adjustment is possible by adjusting the amount of grout material injected according to the injection location.

[0025] Here, "leveling" refers to adjusting the concrete molded body 10 so that it is in a horizontal position without tilting as a whole.

[0026] Figure 7 is a perspective view showing the placement process S14 according to one embodiment, which is carried out by a lifting device. In one embodiment, the grout injection process S16 is performed after the placement process S14. In this grout injection process S16, as shown in Figure 7, first a through hole 32 is formed in the bottom 18 of the concrete molded body 10 that is housed and placed in the recess 24 (first step S16a shown in Figure 1). Then, after the first step S16a, grout material 30 is injected through the through hole 32 between the bottom 18 and the surface (bottom wall surface) of the bottom wall 26 that forms the recess 24 (second step S16b shown in Figure 1).

[0027] According to this embodiment, even if the grout injection process S16 is performed after the placement process S14 in which the concrete molded body 10 is placed in the recess 24, it becomes possible to inject the grout material 30 between the bottom 18 of the concrete molded body 10 and the surface of the bottom wall 26 forming the recess 24 through the through hole 32 formed in the bottom 18 of the concrete molded body 10. Furthermore, since the grout injection process S16 can be performed after the concrete molded body 10 is placed on the bottom wall surface of the recess 24 and the concrete molded body 10 is stably supported on the bottom wall surface of the recess 24, the degree of freedom in the construction order of each step constituting the pit construction method can be increased.

[0028] In one embodiment, multiple through holes 32 are formed at regular intervals in the bottom 18 of the base 12 and the orthogonal portions 14A and 14B, respectively, along the longitudinal direction of the base 12 and the orthogonal portions 14A and 14B. On the other hand, the position in which the through holes 32 are formed is not limited to this.

[0029] In one embodiment, the placement step S14 involves placing the concrete molded body 10, which has been transported to the site where the pit 1 is constructed, into the recess 24 using a lifting device 40. In this case, leveling is performed with at least a portion of the bottom 18 of the concrete molded body 10 in contact with the surface (bottom wall surface) of the bottom wall 26 that forms the recess 24 (leveling step S14a shown in Figure 1). Specifically, the area where the leveling adjustment of the concrete molded body 10 is inspected and confirmed is, for example, the bottom 18 of the concrete molded body 10, or the bottom surface if the bottom 18 is flat.

[0030] Thus, in the placement process S14, while the concrete molded body 10 is lifted by the lifting device 40, at least a portion of the bottom 18 of the concrete molded body 10, that is, a portion or all of the bottom 18, is brought into contact with the surface of the bottom wall 26 of the recess 24, and leveling is performed with the weight of the concrete molded body 10 loaded onto the lifting device 40 reduced, making leveling adjustment easier. In addition, in this leveling step S14a, the weight of the concrete molded body 10 applied to the surface of the bottom wall 26 of the recess 24 is reduced, making it easier to inject the grout material 30 into the bottom wall surface.

[0031] In the embodiment shown in Figure 7, the lifting device 40 has a main body comprising a plurality of support legs 44 erected on the floor surface 20, each having wheels 46 at its lower end, and a frame 42 mounted on the upper ends of the plurality of support legs 44. Meanwhile, a connecting ring 48 is fixed to the upper surface of the bottom 18 of the concrete molded body 10, one end of the lifting wire 50 is connected to the connecting ring 48, and the other end of the lifting wire 50 is connected to the frame 42. The concrete molded body 10 is lifted by the lifting wire 50 and placed in the recess 24.

[0032] Figure 7 shows the case where the orthogonal section 14A, which is manufactured separately from the base 12 and the orthogonal section 14B, is placed in the recess 24. Four connecting rings 48 are fixed to the upper surface of the bottom 18 near both longitudinal ends of the orthogonal section 14A. Two of the four connecting rings 48 are arranged on each longitudinal end side of the orthogonal section 14A, and at each end side, they are spaced apart from each other in the width direction of the bottom 18. This minimizes wobbling of the orthogonal section 14A when it is lifted by four lifting wires 50. The four lifting wires 50 are connected to each of the four connecting rings 48, and in leveling step S14a, the length of each lifting wire 50 is adjusted so that the concrete molded body 10 is in a horizontal position. As a means for adjusting the length of each lifting wire 50, for example, a turnbuckle 52 is used as shown in the figure. When placing the base portion 12 and the orthogonal portion 14B into the recess 24, the procedure is the same as that used for the orthogonal portion 14A.

[0033] In one embodiment, after the first step S16a in which a through hole 32 is formed in the grout injection process S16, the second step S16b in which grout material 30 is injected through the through hole 32 between the bottom 18 and the surface of the bottom wall 26 that forms the recess 24 is performed in parallel with the leveling step S14a.

[0034] According to this embodiment, the second step S16b, in which a through hole 32 is formed and grout material 30 is injected, and the leveling step S14a are performed in parallel. Therefore, while adjusting the concrete molded body 10, which has been lifted by the lifting device 40, to a horizontal position, and while maintaining the horizontal position, at least a part of the bottom 18 of the concrete molded body 10 is in contact with the surface of the bottom wall 26 that forms the recess 24, and the weight of the concrete molded body 10 loaded onto the lifting device 40 is reduced, the grout material 30 is injected between the bottom 18 of the concrete molded body 10 and the surface of the bottom wall 26 that forms the recess 24. In this way, the grout material 30 is injected into the surface of the bottom wall 26 with the weight of the concrete molded body 10 applied to the surface of the bottom wall 26 reduced, making it easier to inject the grout material 30. Furthermore, even after the lifting state by the lifting device 40 is released and the concrete molded body 10 is placed in the recess 24, the leveling state adjusted during lifting can be maintained, so that the concrete molded body 10 can be held precisely horizontally on the bottom wall surface of the recess 24. In addition, since the second step S16b and the leveling step S14a are performed in parallel, the working time required for these steps can be reduced.

[0035] In the embodiment shown in Figure 7, after performing the excavation process S12 to form a recess 24, crushed stone is laid on the surface of the bottom wall 26 that forms the bottom of the recess 24 to form a crushed stone layer 54. Subsequently, the laid crushed stone layer 54 is compacted to increase its density. Furthermore, grout material 30 is injected between the crushed stone layer 54 and the bottom 18 of the concrete molded body 10 in the manner described above. By laying the crushed stone layer 54 on the surface of the bottom wall 26 in this way, the concrete molded body 10 can be supported more stably, and settlement of the concrete molded body 10 can be prevented.

[0036] Furthermore, in the embodiment shown in Figure 7, grout material 30 is filled between the bottom 18 of the concrete molded body 10 and the crushed stone layer 54 or the wall surface forming the recess 24, and grout material 30 is also filled between the upper part of the side wall of the concrete molded body 10 and the upper part of the side wall surface forming the recess 24, thereby filling the gap c between the concrete molded body 10 and the wall surface forming the recess 24. Furthermore, in the region between these upper grout material 30 and bottom grout material 30, river sand 56 is filled between the side wall of the concrete molded body 10 and the wall surface forming the recess 24. This increases the adhesion between the outer wall surface of the concrete molded body 10 and the wall surface forming the recess 24 surrounding the concrete molded body 10, preventing moisture such as rainwater from entering between them. Furthermore, since the bottom 18 of the concrete molded body 10 is stably supported by the crushed stone layer 54 and the grout material 30, settlement of the concrete molded body 10 can be prevented.

[0037] In one embodiment, the grout material 30 may be placed on the surface of the bottom wall 26 forming the recess 24 or on the surface of the crushed stone layer 54 laid on the surface of the bottom wall 26 before the placement step S14 in which the concrete molded body 10 is placed in the recess 24. According to this embodiment, since the grout layer is formed on the open bottom 18 of the recess 24 before the concrete molded body 10 is placed in the recess 24, the workability of forming the grout layer can be improved.

[0038] The contents described in each of the above embodiments can be understood, for example, as follows:

[0039] 1) A method for constructing an automobile pit according to one embodiment is a method for constructing an automobile pit formed below the floor surface (20) of a pit construction site for inspecting or maintaining an automobile, comprising: a manufacturing step (S10) of manufacturing a concrete molded body (10) in a factory having a pair of sides (16a, 16b) and a bottom (18) and having an open top; a transport step (S11) of transporting the concrete molded body (10) manufactured in the manufacturing step (S10) from the factory to the pit construction site; an excavation step (S12) of excavating the floor surface (20) to form a recess (24) on which the concrete molded body (10) can be placed; and a placement step (S14) of placing the concrete molded body (10) in the recess (24).

[0040] With this configuration, the concrete molded body (10) can be manufactured in advance at a factory located in a different location from the pit construction site, thus eliminating the concrete curing period at the pit construction site. Furthermore, because the concrete molded body (10) is manufactured at a different location from the pit construction site, the production of formwork for creating the concrete pouring space at the pit construction site can also be omitted. This makes it possible to shorten the construction period at the pit construction site. In addition, since multiple concrete molded bodies (10) can be manufactured using the same formwork at a dedicated manufacturing plant, the quality of the concrete molded bodies (10) can be standardized, and manufacturing costs can be reduced.

[0041] 2) A method for constructing an automobile pit according to another embodiment further comprises a grout injection step (S16) in which grout material (30) is injected into at least a portion between the concrete molded body (10) and the wall surfaces (24a, 24b) that form the recess (24).

[0042] With this configuration, after placing the concrete molded body (10) in the recess (24), grout material (30) is injected between the concrete molded body (10) and the wall surfaces (24a, 24b) that form the recess (24). This enhances the adhesion between the concrete molded body (10) and the surrounding wall surfaces (24a, 24b), preventing rainwater and other moisture from penetrating between them. Furthermore, since the grout material (30) has good durability and does not shrink, it can stably support the concrete molded body (10) placed in the recess (24), preventing the concrete molded body (10) from settling. Furthermore, when injecting grout material (30) between the bottom (18) of the concrete molded body (10) and the bottom wall surface (24b) that forms the recess (24), the leveling of the concrete molded body (10) can be adjusted by adjusting the amount of grout material (30) injected according to the injection location of the grout material (30).

[0043] 3) A method for constructing an automobile pit according to yet another embodiment is the method for constructing an automobile pit according to 2), wherein the grout injection step (S16) is performed after the installation step (S14) described above, and the grout injection step (S16) includes a first step (S16a) of forming a through hole (32) in the bottom (18) of the concrete molded body (10), and a second step (S16b) after the first step (S16a) of injecting the grout material (30) through the through hole (32) between the bottom (18) and the bottom wall surface (24b) that forms the recess (24).

[0044] With this configuration, even if the grout injection process (S16) is performed after the placement process (S14) in which the concrete molded body (10) is placed in the recess (24), it becomes possible to inject the grout material (30) between the bottom (18) of the concrete molded body (10) and the bottom wall surface (24b) that forms the recess (24) through the through hole (32).

[0045] 4) A method for constructing an automobile pit according to yet another embodiment is the method for constructing an automobile pit described in 3), wherein the installation step (S14) described above includes a leveling step (S14a) in which the concrete molded body (10) is lifted by a lifting device (40) so that the leveling of the concrete molded body (10) can be adjusted while at least a part of the bottom (18) of the concrete molded body (10) is in contact with the bottom wall surface (24b).

[0046] With this configuration, in the placement process (S14), when the concrete molded body (10) is lifted by the lifting device (40) and placed in the recess (24) formed in the floor surface (20), at least a portion of the bottom (18) of the concrete molded body (10) makes contact with the bottom wall surface (24b) of the recess (24), and leveling adjustment is performed while the weight of the concrete molded body (10) loaded onto the lifting device (40) is reduced, thus making the leveling work easier.

[0047] 5) A further embodiment of the method for constructing an automobile pit is the method for constructing an automobile pit described in 4), wherein the second step (S16b) is carried out in parallel with the leveling step (S14a).

[0048] With this configuration, the second step (grout injection step) (S16b) is performed in parallel with the leveling step (S14a). As the concrete molded body (10) lifted by the lifting device (40) is adjusted to a horizontal position, and while maintaining that horizontal position, the grout material (30) is injected between the bottom (18) of the concrete molded body (10) and the bottom wall surface (24b) that forms the recess (24). In this way, the grout material (30) is injected while the body is being lifted, making it easier to inject the grout material (30). Furthermore, since the leveling step (S14a) is performed during lifting, the lifting state by the lifting device (40) is released and the concrete molded body (10) is placed in the recess (24), but the leveling state adjusted during lifting can be maintained, so that the concrete molded body (10) can be held precisely horizontally on the bottom wall surface (24b) of the recess (24). In addition, since the second step (S16b) and the leveling step (S14a) are performed in parallel, the working time required for these steps can be reduced. [Explanation of Symbols]

[0049] 1. Automotive pit 10 Concrete molded body 12 Base 14A, 14B orthogonal section 16a, 16b Side 18 Bottom 20 Floor surface 22 Drilling lines 24 recesses 24a Side wall 24b Bottom wall surface 26 Bottom wall 30 Grout material 32 Through holes 40 Lifting device 42 frames 44 Support leg 46 wheels 48 Connecting ring 50 Lifting wires 52 Turnbuckle 54 Crushed stone layer 56 River Sand Layer O1, O2, O3 opening S1, S2, S3 inner space W1, W2, W3 width dimensions c gap

Claims

1. A method for constructing an automobile pit, which is formed beneath the floor surface of a pit construction site for inspecting or maintaining automobiles, A manufacturing process for producing a concrete molded body in a factory that has a pair of sides and a bottom and an open top, A transport process for transporting the concrete molded body manufactured by the above manufacturing process from the factory to the pit construction site, An excavation step of excavating the floor surface to form a recess on which the concrete molded body can be placed, A placement step of placing the concrete molded body in the recess, Equipped with, The aforementioned concrete molded body is When placed in the aforementioned recess, it is formed in a U-shape in plan view, It is divided into a base portion extending along a first direction, and a pair of orthogonal portions connected at both ends of the base portion along a second direction perpendicular to the first direction. The base and the pair of orthogonal portions are configured to communicate with each other through openings formed at their respective connection points and oriented along the second direction, with the upper open inner spaces formed on the inside of each portion being in communication with each other. Methods for constructing automotive pits.

2. The method for constructing an automobile pit according to claim 1, further comprising a grout injection step of injecting grout material into at least a portion between the concrete molded body and the wall surface forming the recess.

3. The grout injection process is performed after the setting process described above. The aforementioned grout injection process is, The first step is to form a through hole in the bottom of the concrete molded body, A second step is to inject the grout material through the through hole between the bottom and the bottom wall surface forming the recess, A method for constructing an automobile pit according to claim 2, including the following:

4. The placement step includes a leveling step in which the concrete molded body is lifted by a lifting device so that the leveling of the concrete molded body can be adjusted while at least a portion of the bottom of the concrete molded body is in contact with the bottom wall surface. A method for constructing an automobile pit according to claim 3.

5. The second step is carried out in parallel with the leveling step. A method for constructing an automobile pit according to claim 4.

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