JP7330343B1 - Steel-concrete composite structure and construction method for steel-concrete composite structure - Google Patents

Abstract

A steel-concrete composite structure with a lightweight top plate. A steel-concrete composite structure (100) according to the present invention comprises a concrete member (10) having a bottom plate (11) and a pair of side walls (12) extending upward from the bottom plate (11), and a top plate connecting the upper ends of the pair of side walls (12). 20, the top plate 20 includes a square steel pipe 21 having a hollow portion, the square steel pipe 21 is provided so as to be arranged in a plurality in the depth direction of the steel-concrete composite structure 100, and a plurality of square steel pipes are provided. 21 are joined together. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a steel-concrete composite structure and a method for constructing a steel-concrete composite structure.

Steel-concrete composite structures are sometimes used when constructing tunnels and the like.
Patent Literature 1 discloses a structure in which reinforcing bars project obliquely from the top plate member, and the reinforcing bars projecting from the side wall members are arranged in a direction along the reinforcing bars projecting obliquely from the top plate member. ing.
In Patent Document 2, a structure formed by placing a steel shell of a sandwich-type composite top slab on the upper part of a side wall and placing concrete in a state in which reinforcing bars protruding from the upper part of the side wall are placed in the steel shell. is disclosed.

Japanese Unexamined Patent Application Publication No. 2013-127200 Japanese Patent No. 6371571

The top plates of conventional steel-concrete composite structures such as box culverts, including the structure described in Patent Document 1, are mainly made of cast-in-place concrete or precast concrete. If the top slab is made of precast concrete, it is heavy and has a problem of poor transportation efficiency. In addition, when the weight is heavy, it is necessary to prepare a large heavy machine for on-site construction, so there is a problem that workability is lowered.
The structure described in Patent Document 2 uses a steel member (steel shell) as the base of the top plate. The steel shell is lighter than the precast concrete top plate. However, concrete is uniformly placed inside the steel shell after construction. As a result, the weight of the entire structure is increased. As a result, the impact on the ground at the site where the structure is constructed and the impact on the earthquake resistance of the structure become issues.

SUMMARY OF THE INVENTION An object of the present invention is to provide a steel-concrete composite structure having a light-weight top slab.

In order to solve the above problems, the present invention proposes the following means.
A steel-concrete composite structure according to the present invention comprises a bottom plate, a concrete member having a pair of side walls extending upward from the bottom plate, and a top plate connecting upper ends of the pair of side walls, wherein the top plate is provided with a square steel pipe having a hollow portion, the square steel pipe is provided so as to be arranged in a plurality in the depth direction of the steel-concrete composite structure, and the plurality of square steel pipes are joined to each other. do.
A steel-concrete composite structure according to the present invention comprises a bottom plate, a concrete member having a pair of side walls extending upward from the bottom plate, and a top plate connecting upper ends of the pair of side walls, wherein the top plate comprises a square steel pipe having a hollow portion, a plurality of the square steel pipes are provided so as to bridge between the pair of side walls, and the plurality of square steel pipes are joined to each other. do.

According to this invention, the top plate includes a square steel pipe having a hollow portion. That is, the top plate can be formed by arranging the square steel pipe on the side wall. As a result, the top slab can be made lighter than a top slab made of precast concrete or a top slab in which concrete is evenly placed inside a steel shell. Therefore, the top plate can be formed without using large heavy machinery. Therefore, workability can be improved. Also, the weight of the completed steel-concrete composite structure can be reduced. Therefore, the influence on the ground of the construction site and the influence on the earthquake resistance of the structure can be reduced.
Here, when the top slab is made of precast concrete, an earth cover of about 0.5 m is required in order to cope with the wheel load of a vehicle running on the top slab. On the other hand, if the top plate is a square steel pipe, the square steel pipe can directly receive the wheel load and the like. Therefore, by constructing the top slab as described above, it is possible to eliminate the need for an earth cover. Therefore, workability can be improved. Also, the height of the steel-concrete composite structure after construction can be reduced. Furthermore, the dead load can be reduced and the thickness of concrete members can be reduced.

In addition, the top plate further includes a plurality of partition plates arranged inside the square steel pipe and dividing the square steel pipe into a plurality of sections in the axial direction of the square steel pipe, and among the plurality of sections, A penetrating member that penetrates the square steel pipe in a direction orthogonal to the axial direction of the square steel pipe is arranged in a part of the square steel pipe excluding the axial ends of the square steel pipe. Further, the section located at the axial end of the square steel pipe may be filled with concrete.

According to this invention, among the plurality of sections partitioned by the partition plate, the square steel pipe is partially arranged in a direction perpendicular to the axial direction of the square steel pipe, except for the axial ends of the square steel pipe. A penetrating member is disposed therethrough. Thereby, not only square steel pipes adjacent to each other but also three or more square steel pipes arranged in the orthogonal direction can be joined by the penetrating member. Therefore, it is possible to join a larger number of square steel pipes at a time, as compared with the case where each square steel pipe adjacent to each other is individually joined. Therefore, workability can be improved.
Part of the plurality of sections of the square steel pipe and sections located at the ends of the square steel pipe in the axial direction are filled with concrete. As a result, the amount of concrete to be filled can be minimized compared to the case where the entire interior of the square steel pipe is filled with concrete.

Further, an air hole may be provided on the upper surface of the section located at the end in the axial direction of the square steel pipe.

According to this invention, an air hole is provided in the upper surface of the section located at the end in the axial direction of the square steel pipe. This can prevent air from remaining inside the square steel pipe when the section located at the axial end of the square steel pipe is filled with concrete. Therefore, the inside of the square steel pipe can be filled with concrete. Therefore, the square steel pipe can ensure sufficient strength with concrete.

In addition, the concrete member further includes a side wall reinforcing bar arranged inside the side wall, the upper end of which is exposed from the side wall, the upper end of the side wall reinforcing bar being arranged inside the square steel pipe, and the upper end of the side wall reinforcing bar may be characterized in that a bearing plate is joined thereto.

According to this invention, the upper end of the side wall reinforcing bar exposed from the side wall of the concrete member is arranged inside the square steel pipe. Thereby, it is possible to fix the concrete member and the square steel pipe so as not to shift their positions. A bearing plate is joined to the upper end of the sidewall reinforcing bar. As a result, the side wall reinforcing bars placed inside the square steel pipe can be prevented from coming off from the square steel pipe. Further, when the section in which the side wall reinforcing bars are arranged inside the square steel pipe is filled with concrete, the concrete and the side wall reinforcing bars can be reliably fixed.

Further, the bearing pressure plate may be fixed to the upper end of the side wall reinforcing bar by a screwing member.

According to this invention, the bearing plate is fixed to the upper end of the sidewall reinforcing bar by the screwing member. Thereby, the bearing plate can be attached after the side wall reinforcing bars are arranged inside the rectangular steel pipe. Therefore, it is possible to easily perform the work of arranging the side wall reinforcing bars inside the square steel pipe. Therefore, workability can be improved more.

Further, a reinforcing bar through-hole in which the side wall reinforcing bar is arranged is provided on the lower surface of the square steel pipe, and the opening area of the reinforcing bar through-hole may be smaller than the area of the bearing plate.

According to this invention, the lower surface of the square steel pipe is provided with reinforcing bar through-holes in which side wall reinforcing bars are arranged. Thereby, the side wall reinforcing bar can be arranged inside the rectangular steel pipe via the reinforcing bar through-hole. Therefore, it is not necessary to bend the side wall reinforcing bar and insert the end of the side wall reinforcing bar from the end of the rectangular steel pipe in order to arrange the side wall reinforcing bar inside the square steel pipe.

Here, in order to stably arrange the square steel pipe on the concrete member, it is preferable to arrange so that the upper end of the side wall of the concrete member and the lower surface of the square steel pipe are in contact with each other. If the upper end of the side wall reinforcing bar is exposed from the upper end of the side wall and no reinforcing bar through hole is provided in the lower surface of the square steel pipe, it is necessary to provide an area at the upper end of the side wall for the side wall reinforcing bar to extend upward. be. Therefore, it becomes difficult to secure a contact area between the upper end of the side wall and the lower surface of the square steel pipe.

In order to secure a contact area between the upper end of the side wall and the lower surface of the square steel pipe without providing a reinforcing bar through hole in the lower surface of the square steel pipe, for example, the side wall reinforcing bar is exposed from the side surface of the side wall, and the side wall reinforcing bar is appropriately installed. By bending, it becomes necessary to insert the end of the side wall reinforcement from the end of the square steel pipe. This increases the bending points of the sidewall rebar. Therefore, a problem arises in workability.

By providing the reinforcing bar through-holes in the lower surface of the rectangular steel pipe, the side wall reinforcing bars exposed from the upper end of the side wall and extending upward can be arranged inside the rectangular steel pipe without being bent. Therefore, it is possible to easily arrange the square steel pipe so that the lower surface of the square steel pipe is in contact with the upper end of the side wall of the concrete member. Therefore, the square steel pipe can be stably arranged on the concrete member more easily.
The opening area of the reinforcing bar through hole is smaller than the area of the bearing plate. As a result, it is possible to prevent the bearing plate fixed to the side wall reinforcing bar from slipping out of the reinforcing bar through-hole. In addition, by reducing the opening area of the reinforcing bar through-holes, it is possible to minimize the cross-sectional loss of the square steel pipe. Therefore, the influence on the strength of the square steel pipe can be minimized.

Further, the concrete member further includes a side wall reinforcing bar arranged inside the side wall and having an upper end exposed from the side wall, and the top plate is arranged in the square steel pipe and extends in the axial direction of the square steel pipe. It may be characterized by further comprising a rectangular steel pipe rebar extending and one end of which is joined to the upper end of the side wall rebar.

According to this invention, the top plate further includes a square steel pipe reinforcing bar arranged in the square steel pipe and extending in the axial direction of the square steel pipe, one end of which is joined to the upper end of the side wall reinforcing bar. As a result, the ends of the square steel pipe can be reinforced over a wide range along the axial direction of the square steel pipe. Therefore, the square steel pipe can be fixed more stably.

In addition, inside the square steel pipe, the partition plate located at the end in the axial direction of the square steel pipe is used as an end partition plate, and the other end of the square steel pipe reinforcing bar is the end partition plate. It may be characterized by being located in the vicinity.

According to this invention, the other end of the square steel pipe reinforcing bar is positioned near the end partition plate. As a result, the square steel pipe can be reliably fixed and reinforced in the section from the end of the square steel pipe to the end partition plate.

Moreover, it may be characterized by further comprising a mechanical joint that joins the square steel pipe reinforcing bar and the side wall reinforcing bar.

According to this invention, it further comprises a mechanical joint that joins the square steel pipe reinforcing bar and the side wall reinforcing bar. This makes it possible to easily fix the rectangular steel pipe reinforcing bars and the side wall reinforcing bars at the construction site. Therefore, workability can be improved compared to the case where the rectangular steel pipe reinforcing bars and the side wall reinforcing bars are fixed by welding or the like.

Further, a method for constructing a steel-concrete composite structure according to the present invention includes a concrete member installation step of installing a plurality of the concrete members, and a square steel pipe installation step of installing a plurality of the square steel pipes on the concrete members. a square steel pipe connecting step of connecting the plurality of square steel pipes; a reinforcement connecting step of connecting side wall reinforcing bars of the concrete member and square steel pipe reinforcing bars of the square steel pipe; and a concrete filling step of filling concrete in the connecting portion with the shaped steel pipe.

According to this invention, it comprises a concrete member installation process, a square steel pipe installation process, a square steel pipe connection process, a reinforcement connection process, and a concrete filling process.
In other words, the process of installing and fixing the square steel pipe to the concrete member and connecting the square steel pipe and the step of filling the connecting portion between the concrete member and the square steel pipe with concrete are separately provided. Therefore, when the square steel pipe is installed, the inside of the square steel pipe is not filled with concrete. Therefore, when the square steel pipe is installed, the square steel pipe can be made lighter. Thereby, workability can be improved.

Further, the square steel pipe connection step may be performed after the square steel pipe installation step.

According to this invention, the square steel pipe connection step is performed after the square steel pipe installation step. That is, after the square steel pipes are installed on the concrete member in advance, the square steel pipes are connected to each other. Accordingly, the square steel pipes can be connected to each other after the square steel pipes are reliably aligned with each other. Therefore, it is possible to improve the accuracy of alignment between the square steel pipes.

Further, the method may further include a pressure plate installation step of providing a pressure plate on the side wall reinforcing bar having an upper end disposed inside the square steel pipe.

According to the present invention, the step of installing a bearing plate is further included in which the bearing plate is provided on the side wall reinforcing bar whose upper end is arranged inside the square steel pipe. That is, after the upper ends of the side wall reinforcing bars are arranged inside the rectangular steel pipe, the bearing plates are fixed to the upper ends of the side wall reinforcing bars. As a result, when arranging the side wall reinforcing bars inside the square steel pipe, the work can be performed without considering the position, shape, etc. of the bearing plate. Therefore, it is possible to easily perform the work of arranging the side wall reinforcing bars inside the square steel pipe. Therefore, workability can be improved more.

In addition, the connecting portion between the upper end of the side wall and the end portion of the square steel pipe is a corner portion, and in the concrete filling step, concrete is simultaneously poured into the corner portion and the end portion of the square steel pipe. It may be characterized by providing

According to this invention, in the concrete filling step, concrete is placed simultaneously on the corner and on the end of the square steel pipe. As a result, in the steel-concrete composite structure after construction, it is possible to prevent the occurrence of a physical boundary between the side wall and the top slab, which is a square steel pipe. Therefore, the steel-concrete composite structure can be made into a more integral structure. Therefore, performance such as durability and strength of the steel-concrete composite structure can be improved.

According to the present invention, it is possible to provide a steel-concrete composite structure with a lightweight top plate.

1 is a cross-sectional view of a steel-concrete composite structure according to the present invention; FIG. 2 is a plan cross-sectional view of the steel-concrete composite structure shown in FIG. 1; FIG. Figure 2 is a cross-sectional side view of the steel-concrete composite structure shown in Figure 1; FIG. 2 is an enlarged schematic diagram of part IV shown in FIG. 1 ; 1 shows the first state in the steps of the method for constructing a steel-concrete composite structure according to the present invention; It is the second state in the steps of the method for constructing a steel-concrete composite structure according to the present invention. It is the third state in the steps of the method for constructing a steel-concrete composite structure according to the present invention. It is the fourth state in the steps of the method for constructing a steel-concrete composite structure according to the present invention. It is the fifth state in the steps of the method for constructing a steel-concrete composite structure according to the present invention. It is the sixth state in the steps of the method for constructing a steel-concrete composite structure according to the present invention.

Hereinafter, a steel-concrete composite structure 100 according to one embodiment of the present invention will be described with reference to the drawings. The steel-concrete composite structure 100 is used, for example, when constructing a tunnel or the like. The steel-concrete composite structure 100 is a so-called box culvert.
The steel-concrete composite structure 100 includes a concrete member 10, a top plate 20, and a connecting portion 30, as shown in FIG.

The concrete member 10 is located on the underside of the steel-concrete composite structure 100 . The concrete member 10 includes a bottom plate 11 and side walls 12 . As shown in FIG. 1, a concrete member 10 is formed in a U shape by a bottom plate 11 and side walls 12 .
The bottom plate 11 is a member positioned at the U-shaped bottom of the concrete member 10 . The bottom slab 11 is arranged horizontally, for example, at the location where the steel-concrete composite structure 100 is installed. Above the bottom plate 11, for example, along the depth direction Y, which will be described later, can be used as a waterway, and vehicles, pedestrians, and the like can pass.
A side wall 12 extends upward from the bottom plate 11 . A pair of side walls 12 are provided at both ends of the bottom plate 11 .

In the following description, as shown in FIGS. 1, 2 and 3, the direction in which the side wall 12 extends with respect to the concrete member 10 is referred to as the vertical direction Z when indicating the direction. Regarding the pair of side walls 12, the direction from one side wall 12 to the other side wall 12 is called a width direction X. As shown in FIG. A direction orthogonal to both the vertical direction Z and the width direction X is called a depth direction Y. As shown in FIG. In the steel-concrete composite structure 100 according to this embodiment, only one concrete member 10 may be provided. A plurality of concrete members 10 may be provided along the depth direction Y in the steel-concrete composite structure 100 .

The bottom slab 11 and the side walls 12 are individually formed of concrete C, for example, and joined at the construction site. The bottom slab 11 and the side walls 12 may be integrally molded with concrete C. Reinforcement bars (not shown) for reinforcing the concrete C may be arranged inside the bottom plate 11 and the side walls 12 .

The top plate 20 connects the upper ends of the pair of side walls 12 . Vehicles, pedestrians, and the like can pass on the top plate 20 along the width direction X or the depth direction Y, for example. The top plate 20 includes square steel pipes 21 , partition plates 22 , and penetrating members 23 .
The square steel pipe 21 is a pipe member having a hollow portion. In this embodiment, the shape of the cross section orthogonal to the axial direction of the square steel pipe 21 is, for example, a square. The shape of the cross section may be rectangular.

The square steel pipe 21 is arranged so that the axial direction of the square steel pipe 21 is parallel to the width direction X. As shown in FIG. For example, one square steel pipe 21 may be provided for one concrete member. In this embodiment, a plurality of square steel pipes 21 are provided for one concrete member 10 . Specifically, two square steel pipes 21 are provided in the direction orthogonal to the axial direction of the square steel pipes 21 , that is, the depth direction Y for one concrete member 10 . In the present embodiment, the plurality of square steel pipes 21 are arranged with no space between them, as shown in FIG. The plurality of square steel pipes 21 are joined together. In this embodiment, the plurality of square steel pipes 21 are joined by a penetrating member 23, which will be described later. The plurality of square steel pipes 21 may be joined by being welded together.

A plurality of partition plates 22 are arranged inside the rectangular steel pipe 21 . The partition plate 22 is a plate-like member. The partition plate 22 partitions the interior of the square steel pipe 21 into a plurality of sections in the axial direction of the square steel pipe 21 . For example, a steel plate is preferably used for the partition plate 22 . The partition plate 22 is fixed inside the square steel pipe 21 by welding, for example.

The penetrating member 23 is arranged in a part of the plurality of sections separated by the partition plate 22 excluding the axial ends of the square steel pipe 21 . Hereinafter, as shown in FIG. 2, among the plurality of sections partitioned by the partition plate 22, the section in which the penetrating member 23 of the square steel pipe 21 is arranged is referred to as an insertion portion 21h. The penetrating member 23 penetrates in a direction orthogonal to the axial direction of the square steel pipe 21, that is, in the depth direction Y. As shown in FIG. For this reason, a hole for inserting the penetrating member 23 is provided in advance in the penetrating portion 21h. The penetrating member 23 penetrates, for example, a plurality of square steel pipes 21 arranged on one concrete member 10 . Not limited to this, one penetrating member 23 may penetrate a plurality of square steel pipes 21 arranged on a plurality of concrete members 10 arranged in two or more. After the penetrating member 23 is arranged in the penetrating portion 21h, the penetrating portion 21h is filled with concrete C. As shown in FIG. For this reason, the upper surface of the insertion portion 21h of the square steel pipe 21 is provided with a hole for placing the concrete C (not shown). Thereby, the penetrating member 23 joins the square steel pipes 21 provided in the depth direction Y to each other. The penetrating member 23 is, for example, a tubular steel pipe member.

Inside the rectangular steel pipe 21 , among the plurality of sections partitioned by the partition plate 22 , concrete C is filled in the section located at the end in the axial direction of the rectangular steel pipe 21 . For this reason, a hole for placing concrete C is provided in the upper surface of the section located at the end in the axial direction of the square steel pipe 21 (not shown). In the present embodiment, air holes 21ah are provided in the upper surface of a section located at an end in the axial direction of the square steel pipe 21 among the plurality of sections separated by the partition plate 22 .
The air holes 21ah are provided to release the air inside the square steel pipe 21 to the outside of the square steel pipe 21 when the concrete C is filled into the section located at the axial end of the square steel pipe 21 .
A reinforcing bar through-hole 21rh is provided on the lower surface of the square steel pipe 21 . The details of the reinforcing-bar through-holes 21rh will be described together with the connecting portions 30 described later.

The connecting portion 30 connects the concrete member 10 and the top plate 20 . The connecting portion 30 includes a side wall reinforcing bar 31 , a bearing plate 32 , a rectangular steel pipe reinforcing bar 33 , and a mechanical joint 34 .
As shown in FIG. 3 , the sidewall reinforcing bar 31 has its lower end arranged inside the sidewall 12 . The sidewall reinforcing bar 31 has an upper end exposed from the sidewall 12 . The side wall reinforcing bar 31 includes a first side wall reinforcing bar 31a and a second side wall reinforcing bar 31b. Hereinafter, the first side wall reinforcing bar 31a and the second side wall reinforcing bar 31b are referred to as the side wall reinforcing bar 31 when not distinguished from each other.

The upper end of the first side wall reinforcing bar 31 a is arranged inside the rectangular steel pipe 21 . More specifically, the upper end of the side wall reinforcing bar 31 is arranged in a section located at an end in the axial direction of the square steel pipe 21 among a plurality of sections of the square steel pipe 21 separated by the partition plates 22 . . As shown in FIG. 4 , a plurality of first side wall reinforcing bars 31 a are provided in the width direction X with respect to the end of one square steel pipe 21 . A plurality of first side wall reinforcing bars 31 a may be provided in the depth direction Y with respect to the end of one square steel pipe 21 .

The second side wall reinforcing bar 31 b has an upper end connected to one end of the rectangular steel pipe reinforcing bar 33 . As shown in FIG. 4, the second side wall reinforcing bar 31b is arranged, for example, outside the first side wall reinforcing bar 31a in the width direction X. As shown in FIG. One second side wall reinforcing bar 31 b may be provided in the width direction X with respect to the end of one square steel pipe 21 , or a plurality of the second side wall reinforcing bars 31 b may be provided. A plurality of second side wall reinforcing bars 31 b may be provided in the depth direction Y with respect to the end of one square steel pipe 21 .

In this embodiment, the 1st side wall reinforcing bar 31a or the 2nd side wall reinforcing bar 31b is each formed independently, for example. The first side wall reinforcing bar 31a and the second side wall reinforcing bar 31b may be formed integrally at the lower end and branched at the upper end. For example, as shown in FIG. 4, the first side wall reinforcing bars 31a may be branched from the second side wall reinforcing bars 31b arranged along the vertical direction Z. In this case, for example, the lower end of the first side wall reinforcing bar 31a and the intermediate portion of the second side wall reinforcing bar 31b are fixed by a lap joint that secures a lap length.

The first side wall reinforcing bar 31a is arranged inside the square steel pipe 21 through the reinforcing bar through hole 21rh, as shown in FIG. The reinforcing bar through-holes 21rh are provided on the lower surface of the square steel pipe 21 . The reinforcing-bar through-holes 21rh are appropriately provided in accordance with the positions of the first side wall reinforcing bars 31a. A first side wall reinforcing bar 31a is arranged in the reinforcing bar through-hole 21rh. Therefore, the inner diameter of the reinforcing bar through hole 21rh is larger than the outer diameter of the first side wall reinforcing bar 31a.

When arranging the upper end of the first side wall reinforcing bar 31a inside the square steel pipe 21, the square steel pipe 21 is inserted into the side wall 12 while aligning the position of the reinforcing bar through-hole 21rh with the position of the upper end of the first side wall reinforcing bar 31a. Place on top. As a result, the upper end of the first side wall reinforcing bar 31a passes through the reinforcing bar through-hole 21rh and is arranged inside the rectangular steel pipe 21 .

Here, as described above, concrete C is filled in the section located at the axial end of the square steel pipe 21 . Therefore, the upper end of the first side wall reinforcing bar 31a is positioned inside the concrete C. As shown in FIG. As a result, the ends of the square steel pipes 21 are fixed to the upper portions of the side walls 12 . A bearing plate 32 is joined to the upper end of the first side wall reinforcing bar 31a.

The bearing pressure plate 32 is a plate-like member provided to prevent the position of the first side wall reinforcing bar 31a positioned inside the concrete C from being shifted. The area of the pressure plate 32 is desirably larger than the opening area of the reinforcing bar through-holes 21rh. In other words, it is desirable that the opening area of the reinforcing bar through-hole 21rh is smaller than the area of the bearing plate 32 . The area of the bearing plate 32 refers to the area of the surface of the bearing plate 32 facing the reinforcing bar through-hole 21rh.
The bearing pressure plate 32 is fixed to the upper end of the first side wall reinforcing bar 31a by a threaded member N, for example. The threaded member N is, for example, a nut. For this reason, it is preferable that the upper end of the first side wall reinforcing bar 31a is provided with an externally threaded portion. A threaded joint reinforcing bar, for example, may be used at the upper end of the first side wall reinforcing bar 31a. For the screwing member N, for example, a dedicated nut corresponding to a threaded joint reinforcing bar may be used.

The square steel pipe reinforcing bars 33 are arranged inside the square steel pipe 21 . The square steel pipe reinforcing bars 33 extend in the axial direction of the square steel pipe 21 . For example, as shown in FIG. 4 , a plurality of square steel pipe reinforcing bars 33 are provided in the vertical direction Z with respect to the end of one square steel pipe 21 . A plurality of first side wall reinforcing bars 31 a may be provided in the depth direction Y with respect to the end of one square steel pipe 21 .

One end of the square steel pipe reinforcing bar 33 is joined to the upper end of the second side wall reinforcing bar 31b. The other end of the square steel pipe reinforcing bar 33 is located near the end partition plate 22e. The end partition plate 22 e refers to the partition plate 22 located inside the square steel pipe 21 at the axial end of the square steel pipe 21 . In the present embodiment, the vicinity of the end partition plate 22e means that the other end of the square steel pipe reinforcing bar 33 is located at a distance of about 50 mm to 100 mm from the end partition plate 22e in the axial direction of the square steel pipe 21. shall mean that

The mechanical joint 34 joins the rectangular steel pipe reinforcing bar 33 and the side wall reinforcing bar 31 . Thereby, the mechanical joint 34 joins the concrete member 10 and the top plate 20 . As the mechanical joint 34, a known one is appropriately selected and used. For the mechanical joint 34, for example, threaded joints, mortar-filled joints, and end threaded joints are preferably used.

(Construction method for steel-concrete composite structure 100)
Next, a method for constructing the steel-concrete composite structure 100 according to this embodiment will be described. The construction method of the steel-concrete composite structure 100 includes a concrete member installation process, a square steel pipe installation process, a square steel pipe connection process, a reinforcement connection process, a bearing plate installation process, and a concrete filling process.

The concrete member installation process is a process of installing a plurality of concrete members 10 . Specifically, a plurality of concrete members 10 are arranged along the depth direction Y. As shown in FIG. At this time, it is preferable that the plurality of concrete members 10 be arranged without gaps.

The square steel pipe installation step is a step of installing a plurality of square steel pipes 21 on the concrete member 10 . At this time, the square steel pipe 21 is arranged on the concrete member 10 without a gap.
Before the square steel pipe 21 is installed on the concrete member 10, the side wall reinforcing bars 31 are exposed from the upper portion of the side wall 12 as shown in FIG. From this state, as shown in FIG. place on top. Thereby, the upper end of the first side wall reinforcing bar 31 a is arranged inside the square steel pipe 21 .
The partition plate 22 is preferably fixed in advance by welding or the like before the step of installing the square steel pipe. In other words, as shown in FIG. 6, it is preferable that the partition plate 22 is fixed inside the square steel pipe 21 during the installation step of the square steel pipe.

The square steel pipe connecting step is a step of connecting a plurality of square steel pipes 21 . The square steel pipe connection process is performed after the square steel pipe installation process. Specifically, the penetrating member 23 is inserted in the depth direction Y as shown in FIG. As described above, a hole for inserting the penetrating member 23 is provided in advance in the penetrating portion 21h. For this reason, the positions of the holes provided in the plurality of square steel pipes 21 are aligned before performing the square steel pipe connecting step. After inserting the penetrating member 23 through the insertion portion 21h, the insertion portion 21h is filled with concrete C as shown in FIG. Thereby, the square steel pipes 21 arranged in plurality are connected to each other.

As shown in FIG. 8 , the bearing plate installation step is a step of providing a bearing plate 32 on the first side wall reinforcing bar 31 a having its upper end arranged inside the square steel pipe 21 . At this time, the bearing plate 32 is moved into the square steel pipe 21 from the opening at the end of the square steel pipe 21 and arranged on the upper end of the first side wall reinforcing bar 31a. After that, the bearing plate 32 and the upper end of the first side wall reinforcing bar 31a are fixed by the screwing member N. As shown in FIG.
The bearing pressure plate installation process is performed, for example, after the rectangular steel pipe connection process. The pressure plate installation process may be performed after the square steel pipe installation process. In other words, the pressure plate installation process may be performed before the square steel pipe connection process.

The reinforcing bar connection step is a step of connecting the second side wall reinforcing bars 31 b provided in the concrete member 10 and the square steel pipe reinforcing bars 33 provided in the square steel pipe 21 . Specifically, first, as shown in FIG. 9 , the other end of the square steel pipe reinforcing bar 33 is inserted from the end of the square steel pipe 21 . At this time, the other end of the square steel pipe reinforcing bar 33 is positioned near the end partition plate 22e. That is, in the width direction X, the distance between the other end of the square steel pipe reinforcing bar 33 and the end partition plate 22e is set to about 50 mm to 100 mm. After that, a mechanical joint 34 connects one end of the square steel pipe reinforcing bar 33 and the upper end of the second side wall reinforcing bar 31b.

The concrete filling step is a step of filling concrete C in the connecting portion between the concrete member 10 and the rectangular steel pipe 21 .
In the concrete filling step, as shown in FIG. 10 , concrete C is placed simultaneously on the corner portion 30C and the end portion of the square steel pipe 21 . The corner portion 30</b>C is a connection portion between the upper end of the side wall 12 and the end portion of the square steel pipe 21 . By placing the concrete C in this manner, a physical boundary is prevented from occurring at the connecting portion between the side wall 12 and the square steel pipe 21 .
The steel-concrete composite structure 100 is formed by the above steps.

As described above, according to the steel-concrete composite structure 100 according to the present embodiment, the top plate 20 includes the square steel pipes 21 having hollow portions. That is, the top plate 20 can be formed by arranging the square steel pipes 21 on the side walls 12 . As a result, the top slab 20 can be made lighter than a top slab made of precast concrete or a top slab in which concrete is evenly placed inside a steel shell. Therefore, the top plate 20 can be formed without using heavy equipment. Therefore, workability can be improved. Also, the weight of the completed steel-concrete composite structure 100 can be reduced. Therefore, the influence on the ground of the construction site and the influence on the earthquake resistance of the structure can be reduced.

A plurality of square steel pipes 21 are provided in a direction orthogonal to the axial direction of the square steel pipes 21, and the plurality of square steel pipes 21 are joined to each other. Here, when the top plate 20 is made of precast concrete, an earth covering of about 0.5 m is required in order to cope with the wheel load of the vehicle running on the top plate 20 and the like. On the other hand, if the top plate 20 is a square steel pipe 21, the square steel pipe 21 can directly receive a wheel load or the like. Therefore, by configuring the top slab 20 as described above, it is possible to eliminate the need for covering with soil. Therefore, workability can be improved. Also, the height of the steel-concrete composite structure 100 after construction can be reduced. Furthermore, the dead load can be reduced, and the thickness of the concrete member 10 can be reduced.

In addition, among the plurality of sections partitioned by the partition plate 22, the square steel pipe 21 is partially arranged in a direction orthogonal to the axial direction of the square steel pipe 21, except for the axial ends of the square steel pipe 21. A penetrating member 23 is arranged to penetrate. Thus, the penetrating member 23 can join not only the square steel pipes 21 adjacent to each other, but also three or more square steel pipes 21 arranged in the orthogonal direction. Therefore, a larger number of square steel pipes 21 can be joined at once compared to the case where the square steel pipes 21 adjacent to each other are individually joined one by one. Therefore, workability can be improved.
Part of the plurality of sections of the square steel pipe 21 and sections located at the ends of the square steel pipe 21 in the axial direction are filled with concrete C. As a result, compared to the case where the entire inside of the square steel pipe 21 is filled with the concrete C, the amount of the concrete C filled can be minimized.

An air hole 21ah is provided on the upper surface of the section located at the axial end of the square steel pipe 21 . As a result, air can be prevented from remaining inside the square steel pipe 21 when the concrete C is filled in the section located at the axial end of the square steel pipe 21 . Therefore, the inside of the square steel pipe 21 can be filled with the concrete C. Therefore, the square steel pipe 21 can ensure sufficient strength with the concrete C.

Moreover, the upper end of the side wall reinforcing bar 31 exposed from the side wall 12 of the concrete member 10 is arranged inside the rectangular steel pipe 21 . As a result, the concrete member 10 and the rectangular steel pipe 21 can be fixed so as not to be misaligned. A bearing plate 32 is joined to the upper end of the first side wall reinforcing bar 31a. This can prevent the first side wall reinforcing bar 31 a arranged inside the square steel pipe 21 from coming off from the square steel pipe 21 . Moreover, when the concrete C is filled in the section in which the first side wall reinforcing bar 31a is arranged inside the square steel pipe 21, the concrete C and the first side wall reinforcing bar 31a can be reliably fixed.

Further, the bearing pressure plate 32 is fixed by a screwing member N to the upper end of the first side wall reinforcing bar 31a. Thereby, the bearing plate 32 can be attached after the side wall reinforcing bar 31 is arranged inside the rectangular steel pipe 21 . Therefore, the work of arranging the side wall reinforcing bars 31 inside the square steel pipe 21 can be easily performed. Therefore, workability can be improved more.

Further, a reinforcing bar through-hole 21rh in which the first side wall reinforcing bar 31a is arranged is provided in the lower surface of the square steel pipe 21 . Thereby, the first side wall reinforcing bar 31a can be arranged inside the rectangular steel pipe 21 via the reinforcing bar through hole 21rh. Therefore, it is unnecessary to bend the side wall reinforcing bar 31 and insert the end of the first side wall reinforcing bar 31 a from the end of the square steel pipe 21 in order to arrange the side wall reinforcing bar 31 inside the square steel pipe 21 . can be done.

Here, in order to stably arrange the square steel pipe 21 on the concrete member 10, it is preferable to place the upper end of the side wall 12 of the concrete member 10 and the lower surface of the square steel pipe 21 in contact with each other. When the upper end of the first side wall reinforcing bar 31a is exposed from the upper end of the side wall 12, if the reinforcing bar through hole 21rh is not provided in the lower surface of the square steel pipe 21, the first side wall reinforcing bar 31a extends upward. should be provided at the upper edge of the sidewall 12 . Therefore, it becomes difficult to secure a contact area between the upper end of the side wall 12 and the lower surface of the rectangular steel pipe 21 .

In order to secure a contact area between the upper end of the side wall 12 and the lower surface of the square steel pipe 21 without providing the reinforcing bar through hole 21rh in the lower surface of the square steel pipe 21, for example, the side wall reinforcing bar 31 is exposed from the side surface of the side wall 12. It is necessary to insert the end portion of the side wall reinforcing bar 31 from the end portion of the rectangular steel pipe 21 by bending the side wall reinforcing bar 31 appropriately. This increases the bending points of the side wall reinforcing bars 31 . Therefore, a problem arises in workability.

By providing the reinforcing bar through-hole 21rh in the lower surface of the square steel pipe 21, the first side wall reinforcing bar 31a exposed from the upper end of the side wall 12 and extending upward can be arranged inside the square steel pipe 21 without being bent. . Therefore, it is possible to easily arrange the square steel pipe 21 so that the lower surface of the square steel pipe 21 is in contact with the upper end of the side wall 12 of the concrete member 10 . Therefore, the square steel pipe 21 can be stably arranged on the concrete member 10 more easily.
The opening area of the reinforcing bar through hole 21rh is smaller than the area of the bearing plate 32 . This can prevent the pressure plate 32 fixed to the first side wall reinforcing bar 31a from slipping out of the reinforcing bar through-hole 21rh. Further, by reducing the opening area of the reinforcing bar through-hole 21rh, the cross-sectional loss of the square steel pipe 21 can be minimized. Therefore, the influence on the strength of the square steel pipe 21 can be minimized.

Further, the top plate 20 further includes a square steel pipe reinforcing bar 33 which is arranged in the square steel pipe 21 and extends in the axial direction of the square steel pipe 21, and whose one end is joined to the upper end of the second side wall reinforcing bar 31b. Prepare. Thereby, the ends of the square steel pipe 21 can be reinforced over a wide range along the axial direction of the square steel pipe 21 . Therefore, the square steel pipe 21 can be fixed more stably.

The other end of the square steel pipe reinforcing bar 33 is located near the end partition plate 22e. Accordingly, the square steel pipe 21 can be reliably fixed and reinforced in the section from the end of the square steel pipe 21 to the end partition plate 22e.

Moreover, the mechanical joint 34 which joins the square steel pipe reinforcing bar 33 and the 2nd side wall reinforcing bar 31b is further provided. This makes it possible to easily fix the rectangular steel pipe reinforcing bars 33 and the side wall reinforcing bars 31 at the construction site. Therefore, workability can be improved as compared with the case where the square steel pipe reinforcing bar 33 and the second side wall reinforcing bar 31b are fixed by welding or the like.

The method also includes a concrete member installation process, a square steel pipe installation process, a square steel pipe connection process, a reinforcing bar connection process, and a concrete filling process.
That is, the process of installing, fixing and connecting the square steel pipe 21 to the concrete member 10 and the process of filling the connection portion between the concrete member 10 and the square steel pipe 21 with the concrete C are separately provided. Therefore, when the square steel pipe 21 is installed, the concrete C is not filled inside the square steel pipe 21 . Therefore, when the square steel pipe 21 is installed, the square steel pipe 21 can be made lighter. Thereby, workability can be improved.

Further, the square steel pipe connection step is performed after the square steel pipe installation step. That is, after the square steel pipes 21 are installed on the concrete member 10 in advance, the square steel pipes 21 are connected to each other. Accordingly, the square steel pipes 21 can be connected to each other after the positions of the square steel pipes 21 are reliably aligned. Therefore, the accuracy of alignment between the square steel pipes 21 can be improved.

In addition, a bearing plate installing step of providing the bearing plate 32 on the first side wall reinforcing bar 31 a whose upper end is arranged inside the square steel pipe 21 is further included. That is, after the upper end of the first side wall reinforcing bar 31a is arranged inside the rectangular steel pipe 21, the bearing plate 32 is fixed to the upper end of the first side wall reinforcing bar 31a. As a result, when the first side wall reinforcing bars 31 a are arranged inside the square steel pipe 21 , the work can be performed without considering the position and shape of the bearing plate 32 . Therefore, the work of arranging the first side wall reinforcing bars 31a inside the square steel pipe 21 can be easily performed. Therefore, workability can be improved more.

In addition, in the concrete filling step, the concrete C is placed simultaneously on the corner portion 30C and the end portion of the square steel pipe 21 . Thereby, in the steel-concrete composite structure 100 after construction, it is possible to prevent the occurrence of a physical boundary between the side wall 12 and the top plate 20 which is the square steel pipe 21 . Therefore, the steel-concrete composite structure 100 can be made into a more integral structure. Therefore, performance such as durability and strength of the steel-concrete composite structure 100 can be improved.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
For example, although the square steel pipes 21 have been described as being arranged without gaps, the present invention is not limited to this. For example, a plurality of square steel pipes 21 may be joined to each other via steel plates by attaching a steel plate to the upper surface of a plurality of square steel pipes 21 arranged at intervals.
In addition, although it has been described that the square steel pipe 21 is joined by the penetrating member 23 penetrating therethrough, the present invention is not limited to this. For example, the surface of the square steel pipe 21 facing the depth direction Y may be provided with concave and convex shapes corresponding to each other, and these may be fitted or joined with bolts or the like. Moreover, instead of the bearing plate 32, a mechanical fixing may be joined to the upper end of the first side wall reinforcing bar 31a.

In addition, it is possible to appropriately replace the constituent elements in the above-described embodiment with well-known constituent elements without departing from the spirit of the present invention, and the modifications described above may be combined as appropriate.

10 Concrete member 11 Bottom plate 12 Side wall 20 Top plate 21 Square steel pipe 21ah Air hole 21rh Reinforcing bar through hole 22 Partition plate 22e End partition plate 23 Penetration member 30C Corner 31 Side wall reinforcing bar 32 Bearing plate 33 Square steel pipe reinforcing bar 100 Steel concrete Composite structure C Concrete N Threaded member

Claims (14)

a concrete member comprising a bottom plate and a pair of side walls extending upward from the bottom plate;
a top plate connecting the upper ends of the pair of side walls;
with
The top plate comprises a square steel pipe having a hollow portion,
The square steel pipe extends in a direction substantially perpendicular to the depth direction of the steel-concrete composite structure, and is arranged in a plurality,
The plurality of square steel pipes are joined together ,
The concrete member further comprises a side wall reinforcing bar disposed inside the side wall and having an upper end exposed from the side wall,
The upper end of the side wall reinforcing bar is arranged inside the square steel pipe,
A steel-concrete composite structure characterized by: a concrete member comprising a bottom plate and a pair of side walls extending upward from the bottom plate;
a top plate connecting the upper ends of the pair of side walls;
with
The top plate comprises a square steel pipe having a hollow portion,
A plurality of the square steel pipes are provided so as to span between the pair of side walls,
The plurality of square steel pipes are joined together ,
The concrete member further comprises a side wall reinforcing bar disposed inside the side wall and having an upper end exposed from the side wall,
The upper end of the side wall reinforcing bar is arranged inside the square steel pipe,
A steel-concrete composite structure characterized by: The top plate further comprises a plurality of partition plates arranged inside the square steel pipe and dividing the square steel pipe into a plurality of sections in the axial direction of the square steel pipe,
A penetrating member that penetrates the square steel pipe in a direction orthogonal to the axial direction of the square steel pipe is arranged in a part of the plurality of sections excluding the axial ends of the square steel pipe,
Part of the plurality of sections and the section located at the axial end of the square steel pipe are filled with concrete,
A steel-concrete composite structure according to claim 1 or 2, characterized in that: An air hole is provided on the upper surface of the section located at the axial end of the square steel pipe,
A steel-concrete composite structure according to claim 3, characterized in that: A bearing plate is joined to the upper end of the side wall reinforcing bar,
A steel-concrete composite structure according to claim 4, characterized in that: The bearing pressure plate is fixed to the upper end of the side wall reinforcing bar by a screwing member.
A steel-concrete composite structure according to claim 5, characterized in that: The lower surface of the square steel pipe is provided with a reinforcing bar through hole in which the side wall reinforcing bar is arranged,
The opening area of the reinforcing bar through hole is smaller than the area of the bearing plate,
A steel-concrete composite structure according to claim 6, characterized in that: The top plate further comprises a square steel pipe reinforcing bar arranged in the square steel pipe and extending in the axial direction of the square steel pipe, one end of which is joined to the upper end of the side wall reinforcing bar.
A steel-concrete composite structure according to claim 7, characterized in that: In the interior of the square steel pipe, a partition plate positioned at an end in the axial direction of the square steel pipe is used as an end partition plate,
The other end of the square steel pipe reinforcing bar is located near the end partition plate,
A steel-concrete composite structure according to claim 8, characterized in that: Further comprising a mechanical joint that joins the square steel pipe reinforcing bar and the side wall reinforcing bar,
A steel-concrete composite structure according to claim 9, characterized in that: A method for constructing a steel-concrete composite structure according to claim 1 or 2,
a concrete member installation step of installing a plurality of the concrete members;
a square steel pipe installation step of installing a plurality of square steel pipes on the concrete member;
a square steel pipe connecting step of connecting the plurality of square steel pipes;
a reinforcing bar connecting step of connecting the side wall reinforcing bar provided in the concrete member and the square steel pipe reinforcing bar provided in the square steel pipe;
a concrete filling step of filling concrete in a connecting portion between the concrete member and the square steel pipe;
comprising
A construction method for a steel-concrete composite structure characterized by: The square steel pipe connection step is performed after the square steel pipe installation step,
The method for constructing a steel-concrete composite structure according to claim 11, characterized in that: Further comprising a pressure plate installation step of providing a pressure plate on a side wall reinforcing bar having an upper end disposed inside the square steel pipe,
The method for constructing a steel-concrete composite structure according to claim 12, characterized in that: A connecting portion between the upper end of the side wall and the end portion of the square steel pipe is a corner portion,
In the concrete filling step, concrete is placed simultaneously in the corner portion and the end portion of the square steel pipe.
The method for constructing a steel-concrete composite structure according to claim 13, characterized in that:

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