JP2023184126A - Steel-concrete composite structure and construction method of steel-concrete composite structure - Google Patents

Abstract

To provide a steel-concrete composite structure including a lightweight top plate.SOLUTION: A disclosed steel-concrete composite structure 100 includes: a concrete member 10 that includes a bottom plate 11 and a pair of side walls 12 extending upward from the bottom plate 11; and a top plate 20 connecting the tops of the pair of side walls 12. The top plate 20 includes square steel pipes 21 each having a hollow part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a steel-concrete composite structure and a method of constructing a steel-concrete composite structure.

Steel-concrete composite structures are sometimes used when constructing tunnels, etc.
Patent Document 1 discloses a structure in which reinforcing bars protrude obliquely from a top plate member, and reinforcing bars protruding from a side wall member are disposed in a direction along the reinforcing bars protruding diagonally from the top plate member. ing.
Patent Document 2 discloses a structure in which a steel shell of a sandwich-type composite top slab is placed on the top of the side wall, and concrete is poured with reinforcing bars protruding from the top of the side wall placed inside the steel shell. is disclosed.

Japanese Patent Application Publication No. 2013-127200 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 problems with poor transportation efficiency. In addition, if the weight is heavy, it is necessary to prepare large heavy machinery for on-site construction, which poses the problem of reduced workability.
In the structure described in Patent Document 2, a steel member (steel shell) is used as the base of the top plate. The steel shell is lighter than the precast concrete top slab. However, concrete is poured uniformly inside the steel shell after construction. As a result, the overall weight of the structure increases. This raises the issue of the impact on the ground at the site where the structure is being constructed and the impact on the earthquake resistance of the structure.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a steel-concrete composite structure equipped with a lightweight 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 includes a bottom slab, a concrete member including a pair of side walls extending upward from the bottom slab, and a top slab connecting upper ends of the pair of side walls, the top slab is characterized by comprising a square steel pipe having a hollow portion.

According to this invention, the top plate includes a square steel pipe having a hollow portion. In other words, the top plate can be formed by arranging the square steel pipe on the side wall. Thereby, the top slab can be made lighter compared to a top slab made of precast concrete or a top slab in which concrete is uniformly poured inside a steel shell. Therefore, the top plate can be formed without using large heavy machinery. Therefore, workability can be improved. Furthermore, the weight of the completed steel-concrete composite structure can be reduced. Therefore, the influence on the ground at the construction site and the earthquake resistance of the structure can be reduced.

Further, a plurality of the square steel pipes may be provided in a direction perpendicular to the axial direction of the square steel pipe, and the plurality of square steel pipes may be joined to each other.

According to this invention, a plurality of square steel pipes are provided in a direction perpendicular to the axial direction of the square steel pipe, and the plurality of square steel pipes are joined to each other. Here, if the top slab is made of precast concrete, a soil cover of about 0.5 m is required to accommodate the wheel load of vehicles traveling on the top slab. On the other hand, if the top plate is a square steel pipe, the square steel pipe can directly receive wheel loads and the like. Therefore, by making the top slab have the above-described structure, it is possible to eliminate the need for covering with soil. Therefore, workability can be improved. Furthermore, the height of the steel-concrete composite structure after construction can be reduced. Furthermore, dead loads can be reduced and concrete members can be made thinner.

The top plate further includes a plurality of partition plates disposed inside the square steel pipe to divide 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 disposed in a part of the square steel pipe other than the axial end, and a penetrating member that penetrates the square steel pipe in a direction perpendicular to the axial direction of the square steel pipe is arranged, and a part of the plurality of sections 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 partition plates, the square steel pipe is inserted into a part of the square steel pipe in a direction perpendicular to the axial direction of the square steel pipe, excluding the axial end of the square steel pipe. A penetrating member is disposed therethrough. Thereby, the penetrating member can join not only square steel pipes that are adjacent to each other, but also three or more square steel pipes that are lined up in the orthogonal direction. Therefore, compared to the case where adjacent square steel pipes are individually joined one by one, a larger number of square steel pipes can be joined at once. Therefore, workability can be improved.
Parts 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. Thereby, compared to the case where the entire inside of the square steel pipe is filled with concrete, the amount of concrete filled can be reduced to the necessary minimum.

Moreover, 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, air holes are provided on 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 filling the section located at the axial end of the square steel pipe with concrete. Therefore, the inside of the square steel pipe can be filled with concrete. Therefore, the square steel pipe can ensure sufficient strength due to the concrete.

The concrete member further includes a side wall reinforcing bar that is disposed inside the side wall and has an upper end exposed from the side wall, and the upper end of the side wall reinforcing bar is disposed inside the square steel pipe, and the upper end of the side wall reinforcing bar is disposed inside the square steel pipe. may be characterized in that a bearing pressure plate is joined.

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 that their positions do not shift. A bearing plate is connected to the upper end of the side wall reinforcement. Thereby, the side wall reinforcing bars arranged inside the square steel pipe can be prevented from coming off from the square steel pipe. Further, when concrete is filled in the section where the side wall reinforcing bars are arranged inside the square steel pipe, 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 threaded member.

According to this invention, the bearing pressure plate is fixed to the upper end of the side wall reinforcing steel by a threaded member. Thereby, the bearing pressure plate can be attached after the side wall reinforcing bars are arranged inside the square steel pipe. Therefore, the work of arranging the side wall reinforcing bars inside the square steel pipe can be easily performed. Therefore, workability can be further improved.

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

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

Here, in order to stably arrange the square steel pipe on the concrete member, it is preferable to arrange the square steel pipe 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 reinforcement is exposed from the upper end of the side wall and no reinforcement through hole is provided on the bottom 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 reinforcement to extend upward. be. For this reason, 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 ensure a contact area between the upper end of the side wall and the lower surface of the square steel tube without providing a reinforcing bar through hole on the lower surface of the square steel tube, for example, the side wall reinforcing bar may be exposed from the side surface of the side wall, and the side wall reinforcing bar may be inserted as appropriate. By bending, it is 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 reinforcement. Therefore, a problem arises in workability.

By providing the reinforcing bar through holes on the lower surface of the square steel pipe, the side wall reinforcing bars that are exposed from the upper end of the side wall and extend upward can be placed inside the square 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 more easily and stably arranged on the concrete member.
The opening area of the reinforcing bar through hole is smaller than the area of the bearing plate. Thereby, the bearing pressure plate fixed to the side wall reinforcing bar can be prevented from coming off from the reinforcing bar through hole. Furthermore, by reducing the opening area of the reinforcing bar through-hole, cross-sectional defects in the square steel pipe can be minimized. Therefore, the influence on the strength of the square steel pipe can be minimized.

The concrete member further includes a side wall reinforcing bar placed inside the side wall and having an upper end exposed from the side wall, and the top plate is placed inside the square steel pipe and extends in the axial direction of the square steel pipe. It may further include a rectangular steel pipe reinforcing bar that extends and has one end joined to the upper end of the side wall reinforcing bar.

According to this invention, the top plate further includes a square steel pipe reinforcing bar that is disposed within the square steel pipe, extends in the axial direction of the square steel pipe, and has one end joined to the upper end of the side wall reinforcing bar. Thereby, the end portion 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.

Further, inside the square steel pipe, a partition plate located at an end in the axial direction of the square steel pipe is an end partition plate, and the other end of the square steel pipe reinforcing bar is connected to the end partition plate. It may also be characterized by being located nearby.

According to this invention, the other end of the square steel pipe reinforcing bar is located near the end partition plate. Thereby, 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 bars and the side wall reinforcing bars.

According to this invention, a mechanical joint for joining the square steel pipe reinforcing bars and the side wall reinforcing bars is further provided. Thereby, the square steel pipe reinforcing bars and the side wall reinforcing bars can be easily fixed at the construction site. Therefore, workability can be improved compared to the case where the square steel pipe reinforcing bars and the side wall reinforcing bars are fixed by welding or the like.

Further, the 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 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 bars of the concrete member and the square steel pipe reinforcing bars of the square steel pipe; and the step of connecting the concrete member and the corner steel pipe. The present invention is characterized by comprising a concrete filling step of filling concrete into the connection portion with the shaped steel pipe.

According to this invention, the concrete member installation process, the square steel pipe installation process, the square steel pipe connection process, the reinforcing bar connection process, and the concrete filling process are provided.
In other words, the process of installing, fixing and connecting the square steel pipe to the concrete member, and the process of filling the joint between the concrete member and the square steel pipe with concrete are separately provided. Therefore, when installing the square steel pipe, the inside of the square steel pipe is not filled with concrete. Therefore, when installing the square steel pipe, it is possible to make the square steel pipe lighter. Thereby, workability can be improved.

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

According to this invention, the square steel pipe connection process is performed after the square steel pipe installation process. That is, after the square steel pipes are installed on the concrete member in advance, the square steel pipes are connected to each other. Thereby, the square steel pipes can be connected to each other after the square steel pipes have been reliably aligned. Therefore, the accuracy of positioning the square steel pipes with each other can be improved.

Further, the method may further include a step of installing a bearing pressure plate on a side wall reinforcing bar whose upper end is disposed inside the square steel pipe.

According to this invention, the method further includes a step of installing a bearing pressure plate on the side wall reinforcing steel whose upper end is arranged inside the square steel pipe. That is, after the upper end of the side wall reinforcing bar is placed inside the square steel pipe, the bearing plate is fixed to the upper end of the side wall reinforcing bar. Thereby, when arranging the side wall reinforcing bars inside the square steel pipe, the work can be done without considering the position, shape, etc. of the bearing plate. Therefore, the work of arranging the side wall reinforcing bars inside the square steel pipe can be easily performed. Therefore, workability can be further improved.

Further, the connection part between the upper end of the side wall and the end of the square steel pipe is a corner part, and in the concrete filling step, concrete is poured into the corner part and the end of the square steel pipe at the same time. The feature may be that the

According to this invention, in the concrete filling process, concrete is poured into the corner portion and the end portion of the square steel pipe at the same time. Thereby, in the steel-concrete composite structure after construction, it is possible to prevent a physical boundary from occurring 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 integrated 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 slab.

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

Hereinafter, a steel-concrete composite structure 100 according to an 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.
As shown in FIG. 1, the steel-concrete composite structure 100 includes a concrete member 10, a top slab 20, and a connecting portion 30.

The concrete member 10 is located on the lower side of the steel-concrete composite structure 100. The concrete member 10 includes a bottom plate 11 and a side wall 12. As shown in FIG. 1, the concrete member 10 is formed into a U-shape by a bottom plate 11 and side walls 12.
The bottom plate 11 is a member located at the U-shaped bottom of the concrete member 10. The bottom plate 11 is, for example, placed horizontally at a location where the steel-concrete composite structure 100 is installed. The top of the bottom plate 11 can be used as a waterway, and vehicles, pedestrians, etc. can pass along the depth direction Y, which will be described later, for example.
The 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, when indicating a direction, the direction in which the side wall 12 extends with respect to the concrete member 10 will be referred to as the vertical direction Z. Regarding the pair of side walls 12, the direction from one side wall 12 to the other side wall 12 is referred to as the width direction X. A direction perpendicular to both the vertical direction Z and the width direction X is referred to as a depth direction Y. In the steel-concrete composite structure 100 according to this embodiment, only one concrete member 10 may be provided. In the steel-concrete composite structure 100, a plurality of concrete members 10 may be provided along the depth direction Y.

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

The top plate 20 connects the upper ends of the pair of side walls 12. Vehicles, pedestrians, etc. can pass over the top plate 20, for example, along the width direction X or the depth direction Y. The top plate 20 includes a square steel pipe 21, a partition plate 22, and a penetrating member 23.
The square steel pipe 21 is a pipe member having a hollow portion. In this embodiment, the shape of the cross section perpendicular to the axial direction of the square steel pipe 21 is, for example, 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. 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 for one concrete member 10 in a direction perpendicular to the axial direction of the square steel pipe 21, that is, in the depth direction Y. In this embodiment, a plurality of square steel pipes 21 are arranged without gaps between each other, as shown in FIG. 2 . The plurality of square steel pipes 21 are joined to each other. 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 welding to each other.

A plurality of partition plates 22 are arranged inside the square steel pipe 21 . The partition plate 22 is a plate-shaped member. The partition plate 22 divides the inside 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 to the inside of the square steel pipe 21 by welding, for example.

The penetrating member 23 is arranged in a part of the plurality of sections partitioned by the partition plate 22 except for the axial end of the square steel pipe 21. Hereinafter, as shown in FIG. 2, among the plurality of sections partitioned by the partition plates 22, the section of the square steel pipe 21 where the penetrating member 23 is arranged will be referred to as the insertion section 21h. The penetrating member 23 penetrates the square steel pipe 21 in a direction perpendicular to the axial direction, that is, in the depth direction Y. For this reason, a hole for inserting the penetrating member 23 is provided in advance in the insertion portion 21h. The penetrating member 23 penetrates, for example, a plurality of square steel pipes 21 placed on one concrete member 10. The present invention is not limited to this, and one penetrating member 23 may penetrate a plurality of square steel pipes 21 arranged on a plurality of concrete members 10 arranged two or more. After the penetration member 23 is placed in the insertion portion 21h, the penetration portion 21h is filled with concrete C. For this reason, a hole for pouring concrete C is provided on the upper surface of the insertion portion 21h of the square steel pipe 21 (not shown). Thereby, the penetrating member 23 joins a plurality of square steel pipes 21 provided in the depth direction Y. The penetrating member 23 is, for example, a circular steel pipe member.

Inside the square steel pipe 21, among the plurality of sections partitioned by the partition plates 22, the section located at the end of the square steel pipe 21 in the axial direction is filled with concrete C. For this reason, a hole for pouring concrete C is provided on the upper surface of the section located at the end in the axial direction of the square steel pipe 21 (not shown). In this embodiment, air holes 21ah are provided on the upper surface of the section located at the axial end of the square steel pipe 21 among the plurality of sections partitioned by the partition plate 22.
The air holes 21ah are provided to allow air inside the square steel pipe 21 to escape to the outside of the square steel pipe 21 when filling the section located at the axial end of the square steel pipe 21 with concrete C.
A reinforcing bar through hole 21rh is provided on the lower surface of the square steel pipe 21. Details of the reinforcing bar through hole 21rh will be explained together with the connection portion 30 described later.

The connecting portion 30 connects the concrete member 10 and the top slab 20. The connecting portion 30 includes side wall reinforcing bars 31, a bearing plate 32, square steel pipe reinforcing bars 33, and a mechanical joint 34.
As shown in FIG. 3, the side wall reinforcing bars 31 have lower ends arranged inside the side wall 12. The upper end of the side wall reinforcing bar 31 is exposed from the side wall 12. The side wall reinforcing bars 31 include a first side wall reinforcing bar 31a and a second side wall reinforcing bar 31b. Hereinafter, when the first side wall reinforcing bars 31a and the second side wall reinforcing bars 31b are not distinguished, they will be referred to as side wall reinforcing bars 31.

The upper end of the first side wall reinforcing bar 31 a is arranged inside the square steel pipe 21 . More specifically, the upper end of the side wall reinforcing bar 31 is arranged in the section located at the end of the square steel pipe 21 in the axial direction, among the 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 31a are provided in the width direction X at the end of one square steel pipe 21. A plurality of first side wall reinforcing bars 31a may be provided in the depth direction Y with respect to the end of one square steel pipe 21.

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

In this embodiment, the first side wall reinforcing bars 31a or the second side wall reinforcing bars 31b are each formed independently, for example. The first side wall reinforcing bars 31a and the second side wall reinforcing bars 31b may be formed so that their lower ends are integrally formed and their upper ends are branched. For example, as shown in FIG. 4, the first side wall reinforcing bars 31a may be formed to branch 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 with a sufficient lap length.

As shown in FIG. 4, the first side wall reinforcing bars 31a are arranged inside the square steel pipe 21 through the reinforcing bar through holes 21rh. The reinforcing bar through hole 21rh is provided on the lower surface of the square steel pipe 21. The reinforcing bar through hole 21rh is provided as appropriate in accordance with the position of the first side wall reinforcing bar 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 placing the upper end of the first side wall reinforcing bar 31a inside the square steel pipe 21, align the position of the reinforcing bar through hole 21rh with the upper end of the first side wall reinforcing bar 31a, and place the square steel pipe 21 inside the side wall 12. Place it at the top. Thereby, the upper end of the first side wall reinforcing bar 31a passes through the reinforcing bar through hole 21rh and is disposed inside the square steel pipe 21.

Here, as described above, the section located at the end of the square steel pipe 21 in the axial direction is filled with concrete C. Therefore, the upper end of the first side wall reinforcing bar 31a will be located inside the concrete C. Thereby, the end of the square steel pipe 21 is fixed to the upper part of the side wall 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-shaped member provided to prevent the position of the first side wall reinforcement 31a located inside the concrete C from shifting. The area of the bearing pressure plate 32 is desirably larger than the opening area of the reinforcing bar through hole 21rh. In other words, the opening area of the reinforcing bar through hole 21rh is desirably smaller than the area of the bearing pressure plate 32. Note that the area of the bearing pressure plate 32 refers to the area of the surface of the bearing pressure 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 be provided with a male thread. For example, a threaded reinforcing bar may be used at the upper end of the first side wall reinforcing bar 31a. For the threaded member N, for example, a special nut compatible with threaded reinforcing bars 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 31a 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 22e refers to the partition plate 22 located inside the square steel pipe 21 at the end of the square steel pipe 21 in the axial direction. In this 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. It shall mean that

The mechanical joint 34 joins the square steel pipe reinforcing bars 33 and the side wall reinforcing bars 31. Thereby, the mechanical joint 34 joins the concrete member 10 and the top slab 20. As the mechanical joint 34, a known one is appropriately selected and used. As the mechanical joint 34, for example, a threaded reinforcing bar joint, a mortar-filled joint, or an end threaded joint is suitably used.

(Construction method of steel concrete composite structure 100)
Next, a method of constructing the steel-concrete composite structure 100 according to this embodiment will be explained. The construction method for 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 reinforcing bar 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. At this time, it is preferable that the plurality of concrete members 10 are arranged without gaps.

The square steel pipe installation process is a process of installing a plurality of square steel pipes 21 on the concrete member 10. At this time, the square steel pipe 21 is placed on the concrete member 10 without any gaps.
Before the square steel pipe 21 is installed on the concrete member 10, the side wall reinforcing bars 31 are exposed from the upper part of the side wall 12, as shown in FIG. From this state, as shown in FIG. 6, the square steel pipe 21 is inserted into the concrete member 10 while aligning the reinforcing bar through hole 21rh provided on the lower surface of the square steel pipe 21 with the upper end of the first side wall reinforcing bar 31a. Place it on top. Thereby, the upper end of the first side wall reinforcing bar 31a is arranged inside the square steel pipe 21.
Note that it is preferable that the partition plate 22 is fixed in advance by welding or the like before the square steel pipe installation step. That is, as shown in FIG. 6, it is preferable that the partition plate 22 is fixed inside the square steel pipe 21 during the square steel pipe installation process.

The square steel pipe connecting process is a process 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, as shown in FIG. 7, the penetrating member 23 is inserted in the depth direction Y. As described above, the insertion portion 21h is provided with a hole for inserting the penetration member 23 in advance. Therefore, before performing the square steel pipe connection process, the positions of the holes provided in each of the plurality of square steel pipes 21 are aligned. After the penetration member 23 is inserted into the insertion portion 21h, concrete C is filled into the insertion portion 21h, as shown in FIG. Thereby, the plurality of square steel pipes 21 arranged are connected to each other.

The bearing plate installation process is a process of installing the bearing plate 32 on the first side wall reinforcing bar 31a whose upper end is disposed inside the square steel pipe 21, as shown in FIG. At this time, the bearing pressure plate 32 is moved into the interior of the square steel pipe 21 from the opening at the end of the square steel pipe 21 and placed at the upper end of the first side wall reinforcing bar 31a. Thereafter, the bearing pressure plate 32 and the upper end of the first side wall reinforcing bar 31a are fixed by a screw member N.
The bearing plate installation process is performed, for example, after the square steel pipe connection process. The bearing plate installation process may be performed after the square steel pipe installation process. In other words, the bearing pressure plate installation process may be performed before the square steel pipe connection process.

The reinforcing bar connection process is a process of connecting the second side wall reinforcing bars 31b of the concrete member 10 and the square steel pipe reinforcing bars 33 of 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 be approximately 50 mm to 100 mm. Thereafter, one end of the square steel pipe reinforcing bar 33 and the upper end of the second side wall reinforcing bar 31b are connected by the mechanical joint 34.

The concrete filling step is a step of filling concrete C into the connection portion between the concrete member 10 and the square steel pipe 21.
In the concrete filling step, as shown in FIG. 10, concrete C is poured into the corner 30C and the end of the square steel pipe 21 at the same time. The corner portion 30C refers to the connection portion between the upper end of the side wall 12 and the end of the square steel pipe 21. By placing the concrete C in this manner, no physical boundary is created at the connection between the side wall 12 and the square steel pipe 21.
A steel-concrete composite structure 100 is formed through each of the above steps.

As explained above, according to the steel-concrete composite structure 100 according to the present embodiment, the top plate 20 includes the square steel pipe 21 having a hollow portion. That is, by arranging the square steel pipe 21 on the side wall 12, the top plate 20 can be formed. Thereby, the top slab 20 can be made lighter compared to a top slab made of precast concrete or a top slab in which concrete is uniformly poured inside a steel shell. Therefore, the top plate 20 can be formed without using large heavy equipment. Therefore, workability can be improved. Furthermore, the weight of the completed steel-concrete composite structure 100 can be reduced. Therefore, the influence on the ground at the construction site and the earthquake resistance of the structure can be reduced.

Further, 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, if the top slab 20 is made of precast concrete, a soil cover of about 0.5 m is required to accommodate the wheel load of a vehicle traveling on the top slab 20. On the other hand, when the top plate 20 is a square steel pipe 21, the square steel pipe 21 can directly receive wheel loads and the like. Therefore, by making the top slab 20 have the above-described structure, it is possible to eliminate the need for covering with soil. Therefore, workability can be improved. Furthermore, the height of the steel-concrete composite structure 100 after construction can be reduced. Furthermore, the dead load can be reduced and the concrete member 10 can be made thinner.

Furthermore, among the plurality of sections partitioned by the partition plates 22, the square steel pipes 21 are arranged in a direction perpendicular to the axial direction of the square steel pipes 21 in a part excluding the axial ends of the square steel pipes 21. A penetrating member 23 is arranged. Thereby, 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 aligned in the orthogonal direction. Therefore, compared to the case where adjacent square steel pipes 21 are individually joined one by one, a larger number of square steel pipes 21 can be joined at once. Therefore, workability can be improved.
Parts 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. Thereby, compared to the case where the entire inside of the square steel pipe 21 is filled with concrete C, the filling amount of concrete C can be made to the necessary minimum.

Furthermore, an air hole 21ah is provided on the upper surface of the section located at the end of the square steel pipe 21 in the axial direction. This can prevent air from remaining inside the square steel pipe 21 when filling the section located at the axial end of the square steel pipe 21 with concrete C. Therefore, the inside of the square steel pipe 21 can be filled with concrete C. Therefore, the square steel pipe 21 can ensure sufficient strength due to the concrete C.

Further, 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 square steel pipe 21. Thereby, the concrete member 10 and the square steel pipe 21 can be fixed so that their positions do not shift. A bearing plate 32 is joined to the upper end of the first side wall reinforcing bar 31a. Thereby, the first side wall reinforcing bars 31a arranged inside the square steel pipe 21 can be prevented from coming off from the square steel pipe 21. Moreover, when the section where the first side wall reinforcing bars 31a are arranged inside the square steel pipe 21 is filled with concrete C, the concrete C and the first side wall reinforcing bars 31a can be reliably fixed.

Further, the bearing pressure plate 32 is fixed to the upper end of the first side wall reinforcing bar 31a by a threaded member N. Thereby, the bearing pressure plate 32 can be attached after the side wall reinforcing bars 31 are arranged inside the square 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 further improved.

Furthermore, a reinforcing bar through hole 21rh in which the first side wall reinforcing bar 31a is arranged is provided on the lower surface of the square steel pipe 21. Thereby, the first side wall reinforcing bars 31a can be placed inside the square steel pipe 21 via the reinforcing bar through holes 21rh. Therefore, in order to arrange the side wall reinforcing bars 31 inside the square steel pipe 21, it is not necessary to bend the side wall reinforcing bars 31 and inserting the end of the first side wall reinforcing bars 31a from the end of 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 arrange it so that the upper end of the side wall 12 of the concrete member 10 and the lower surface of the square steel pipe 21 are 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 on the lower surface of the square steel pipe 21, the area for the first side wall reinforcing bar 31a to extend upward is must be provided at the upper end of the side wall 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 square steel pipe 21.

In order to ensure 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 on the lower surface of the square steel pipe 21, for example, the side wall reinforcing bars 31 may be exposed from the side surface of the side wall 12. It is necessary to insert the end of the side wall reinforcing bar 31 from the end of the square steel pipe 21 by bending the side wall reinforcing bar 31 appropriately. This increases the number of bending points of the side wall reinforcing bars 31. Therefore, a problem arises in workability.

By providing the reinforcing bar through hole 21rh on 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 placed inside the square steel pipe 21 without bending. . 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 pressure plate 32. Thereby, the bearing pressure plate 32 fixed to the first side wall reinforcing bar 31a can be prevented from coming off from the reinforcing bar through hole 21rh. Furthermore, by reducing the opening area of the reinforcing bar through hole 21rh, cross-sectional defects in 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 inside 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. Be prepared. Thereby, the end portion of the square steel pipe 21 can be reinforced in a wide range along the axial direction of the square steel pipe 21. Therefore, the square steel pipe 21 can be fixed more stably.

Further, the other end of the square steel pipe reinforcing bar 33 is located near the end partition plate 22e. Thereby, 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, a mechanical joint 34 is further provided to join the square steel pipe reinforcing bars 33 and the second side wall reinforcing bars 31b. Thereby, the square steel pipe reinforcing bars 33 and the side wall reinforcing bars 31 can be easily fixed at the construction site. Therefore, workability can be improved compared to the case where the square steel pipe reinforcing bars 33 and the second side wall reinforcing bars 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.
In other words, the work of installing, fixing and connecting the square steel pipe 21 to the concrete member 10 and the process of filling the joint between the concrete member 10 and the square steel pipe 21 with concrete C are separately provided. Therefore, when installing the square steel pipe 21, the inside of the square steel pipe 21 is not filled with concrete C. Therefore, when installing the square steel pipe 21, the square steel pipe 21 can be made lighter. Thereby, workability can be improved.

Moreover, the square steel pipe connection process is performed after the square steel pipe installation process. 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. Thereby, after the square steel pipes 21 are reliably aligned, the square steel pipes 21 can be connected to each other. Therefore, the accuracy of positioning the square steel pipes 21 with each other can be improved.

The method further includes a step of installing a bearing plate 32 on the first side wall reinforcing bar 31a whose upper end is disposed inside the square steel pipe 21. That is, after the upper end of the first side wall reinforcing bar 31a is placed inside the square steel pipe 21, the bearing pressure plate 32 is fixed to the upper end of the first side wall reinforcing bar 31a. Thereby, when arranging the first side wall reinforcing bars 31a inside the square steel pipe 21, it is possible to work without considering the position, shape, etc. of the bearing pressure 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 further improved.

In addition, in the concrete filling step, concrete C is poured into the corner portion 30C and the end portion of the square steel pipe 21 at the same time. Thereby, in the steel-concrete composite structure 100 after construction, it is possible to prevent a physical boundary from occurring between the side wall 12 and the top slab 20, which is the square steel pipe 21. Therefore, the steel-concrete composite structure 100 can have a more integrated structure. Therefore, performance such as durability and strength of the steel-concrete composite structure 100 can be improved.

Note that the technical scope of the present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit of the present invention.
For example, although the square steel pipes 21 have been described as being arranged without any gaps between them, the present invention is not limited thereto. For example, a plurality of square steel pipes 21 may be joined to each other via the steel plate by attaching a steel plate to the upper surface of a plurality of square steel pipes 21 arranged at intervals.
Moreover, although the square steel pipe 21 has been described as being joined by being penetrated by the penetrating member 23, the present invention is not limited to this. For example, corrugated shapes corresponding to each other may be provided on the surface of the square steel pipe 21 facing the depth direction Y, and these may be fitted together, or they may be joined by bolts or the like.
Further, instead of the bearing pressure plate 32, a mechanical fixing member may be joined to the upper end of the first side wall reinforcing bar 31a.

In addition, without departing from the spirit of the present invention, the components in the embodiments described above may be replaced with well-known components as appropriate, and the above-described modifications 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 Rebar penetration hole 22 Partition plate 22e End partition plate 23 Penetration member 30C Corner part 31 Side wall reinforcement 32 Bearing plate 33 Square steel pipe reinforcement 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;
Equipped with
The top plate is equipped with a square steel pipe having a hollow part,
A steel-concrete composite structure characterized by: A plurality of the square steel pipes are provided in a direction perpendicular to the axial direction of the square steel pipe,
The plurality of square steel pipes are joined to each other,
The steel-concrete composite structure according to claim 1, characterized in that: 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,
A penetrating member that penetrates the square steel pipe in a direction orthogonal to the axial direction of the square steel pipe is disposed in a part of the plurality of sections excluding the axial end of the square steel pipe,
Part of the plurality of sections and the section located at the end of the square steel pipe in the axial direction are filled with concrete,
The steel-concrete composite structure according to claim 1 or 2, characterized in that: Air holes are provided on the upper surface of the section located at the axial end of the square steel pipe,
The steel-concrete composite structure according to claim 3, characterized in that: The concrete member further includes a side wall reinforcing bar placed 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 bearing plate is connected to the upper end of the side wall reinforcing steel,
The steel-concrete composite structure according to any one of claims 1 to 4. The bearing pressure plate is fixed to the upper end of the side wall reinforcement by a threaded member.
The steel-concrete composite structure according to claim 5, characterized in that: 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,
The opening area of the reinforcing bar through hole is smaller than the area of the bearing plate,
The steel-concrete composite structure according to claim 5 or 6, characterized in that: The concrete member further includes a side wall reinforcing bar placed inside the side wall and having an upper end exposed from the side wall,
The top plate further includes a square steel pipe reinforcing bar disposed within the square steel pipe, extending in the axial direction of the square steel pipe, and having one end joined to the upper end of the side wall reinforcing bar.
A steel-concrete composite structure according to any one of claims 1 to 7. Inside the square steel pipe, a partition plate located at an end in the axial direction of the square steel pipe is an end partition plate,
The other end of the square steel pipe reinforcing bar is located near the end partition plate,
The steel-concrete composite structure according to claim 8, characterized in that: further comprising a mechanical joint that connects the square steel pipe reinforcing bars and the side wall reinforcing bars;
The steel-concrete composite structure according to claim 8 or 9, characterized in that: A method for constructing a steel concrete composite structure according to any one of claims 1 to 10, comprising:
a concrete member installation step of installing a plurality of the concrete members;
a square steel pipe installation step of installing a plurality of the square steel pipes on the concrete member;
a square steel pipe connecting step of connecting the plurality of square steel pipes;
a reinforcing bar connection step of connecting side wall reinforcing bars of the concrete member and square steel pipe reinforcing bars of the square steel pipe;
a concrete filling step of filling concrete into a joint between the concrete member and the square steel pipe;
Equipped with
A method of constructing a steel-concrete composite structure characterized by: The square steel pipe connecting step is performed after the square steel pipe installation step,
The method for constructing a steel-concrete composite structure according to claim 11. further comprising a bearing plate installation step of providing a bearing plate on the side wall reinforcing steel whose upper end is arranged inside the square steel pipe;
The method for constructing a steel-concrete composite structure according to claim 11 or 12. The connection part between the upper end of the side wall and the end of the square steel pipe is a corner part,
In the concrete filling step, concrete is poured into the corner and the end of the square steel pipe at the same time.
The method for constructing a steel-concrete composite structure according to any one of claims 11 to 13.

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