Steel plate concrete structure

Abstract

In light of the fact that increasing the wall thickness of a steel plate concrete structure applied to the ceiling of a building increases the weight of the upper part of the building and reduces the building's seismic resistance, the objective is to provide a steel plate concrete structure that can improve impact resistance without increasing the wall thickness. [Solution] The device consists of a rectangular steel plate, a steel member positioned on the outer perimeter of the steel plate and having a flange provided along the steel plate, and concrete filled in the space defined by the steel plate and the steel member, with the steel plate and the steel member connected at the flange.

Description

Technical Field

[0001] The present invention relates to a steel plate - concrete structure.

Background Art

[0002] A steel plate - concrete structure is a structure in which a region sandwiched between steel plates is filled with concrete, and it has a different structure from a reinforced - concrete structure in which reinforcing bars are arranged inside the concrete.

[0003] As a conventional technology related to a steel plate - concrete structure, for example, the one described in Patent Document 1 is known. Patent Document 1 discloses a steel plate - concrete structure including a pair of surface steel plates, a concrete part composed of concrete placed in the space between the surface steel plates, and a partition part that connects the surface steel plates and is embedded in the concrete part. The partition part has a plate - shaped steel standing plate part provided so as to rise in the out - of - plane direction from each surface steel plate, and a standing plate connecting part that connects the standing plate parts.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the new regulatory standards for nuclear power plants established after the accident at the Fukushima Daiichi Nuclear Power Plant, for example, for terrorist acts such as deliberately colliding heavy objects such as aircraft and missiles or high - speed flying objects against the reactor building, it is required to safely stop the reactor and maintain a cold shutdown state. As one design guideline for cold - shutting down the reactor against the collision of a heavy object, it is possible to design the building outer wall to be robust so that the reactor building is non - penetrable even during the collision of a heavy object.

[0006] To prevent penetration of building exterior walls against large impact loads from heavy object collisions, it is conceivable to use a steel plate concrete structure, which has higher impact resistance than reinforced concrete structures, and to design the wall thickness to be thicker. However, increasing the wall thickness also increases the weight of the steel plate concrete structure. Therefore, especially when a steel plate concrete structure is applied to the ceiling of a building, the weight of the upper part of the building becomes large, reducing the building's seismic resistance.

[0007] The present invention has been made in view of the above, and aims to provide a steel plate concrete structure that can improve impact resistance without increasing the wall thickness. [Means for solving the problem]

[0008] The present invention includes several means for solving the above-mentioned problems, but one example is a rectangular steel plate, a steel member arranged on the outer periphery of the steel plate and having a flange provided along the steel plate, and concrete filled in the space defined by the steel plate and the steel member, wherein the steel plate and the steel member are connected at the flange. [Effects of the Invention]

[0009] According to the present invention, impact resistance can be improved without increasing the wall thickness. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example of a building structure that utilizes a steel plate concrete structure. [Figure 2] This diagram schematically illustrates a single unit of a steel plate concrete structure. [Figure 3] Figure 2 is a cross-sectional view of the CC plane. [Figure 4] This figure shows an example of the manufacturing procedure for a steel plate concrete structure. [Figure 5] This figure shows an example of the manufacturing procedure for a steel plate concrete structure. [Figure 6] This figure shows an example of the manufacturing procedure for a steel plate concrete structure. [Figure 7] This diagram shows a magnified view of a portion of a typical steel plate concrete structure. [Figure 8] This diagram shows a magnified view of a portion of a steel plate concrete structure during an impact by an flying object. [Figure 9] This figure shows a comparative example of a conventional steel plate concrete structure. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the present invention will be described with reference to Figures 1 to 9.

[0012] Figure 1 shows an example of a building structure to which the steel plate concrete structure according to this embodiment is applied.

[0013] The building shown in Figure 1 consists of an exterior wall structure 11 that surrounds the outer perimeter and a roof structure 10 that is provided to cover the upper opening of the exterior wall structure 11.

[0014] The roof structure 10 has a steel plate reinforced concrete (SC) structure composed of multiple steel members 20a arranged horizontally and functioning as beams, and multiple steel members 20b arranged so as to intersect with the steel members 20a and functioning as beams. Multiple steel members 20a and 20b are arranged at predetermined intervals (an interval calculated from the strength required for the roof structure 10, for example, several meters). Here, the structure enclosed by the steel members 20a and 20b within the roof structure 10 is defined as a single unit, the steel plate reinforced concrete structure 100.

[0015] FIG. 2 is a diagram schematically showing one unit of the steel plate concrete structure. FIG. 3 is a cross-sectional view taken along the C-C plane in FIG. 2. In FIGS. 2 and 3, a coordinate space composed of an X-axis and a Y-axis that are perpendicular to each other and provided along the horizontal direction, and a Z-axis provided along the vertical direction will be defined for explanation.

[0016] As shown in FIGS. 2 and 3, the steel plate concrete structure 100 includes a pair of steel members 20a arranged in parallel with a gap therebetween, a pair of steel members 20b arranged in parallel with a gap therebetween and each spanned between the pair of steel members 20a, a rectangular (including a rectangle) steel plate 50b arranged on the inner surface B on the indoor side of the building, a rectangular (including a rectangle) steel plate 50a arranged on the outer surface A on the outdoor side of the building, and concrete 30 filled in the space defined by the pair of steel members 20a, the pair of steel members 20b, and the steel plates 50a and 50b. The steel plate concrete structure 100 is configured such that the side formed by the steel member 20a is longer than the side formed by the steel member 20b. That is, in the steel plate concrete structure 100, the steel member 20a is arranged along the longitudinal direction (for example, the Y-axis direction), and the steel member 20b is arranged along the short-side direction (for example, the X-axis direction).

[0017] The steel member 20a includes a web portion 21a arranged along a direction perpendicular to the inner surface B and the outer surface A of the steel plate concrete structure 100, and flanges 80a and 80b formed to extend along the outer surface A and the inner surface B from the end portions on the outer surface A side and the inner surface B side of the web portion 21a, respectively (see FIG. 4 and the like later). Similarly, the steel member 20b includes a web portion 21b arranged along a direction perpendicular to the inner surface B and the outer surface A of the steel plate concrete structure 100, and flanges 90a and 90b formed to extend along the outer surface A and the inner surface B from the end portions on the outer surface A side and the inner surface B side of the web portion 21b, respectively (see FIG. 4 and the like later). That is, in the steel plate concrete structure 100, the concrete 30 is filled and arranged so as to be sandwiched between the opposing web portions 21a of the pair of steel members 20a and between the opposing web portions 21b of the pair of steel members 20b.

[0018] The steel member 20b is arranged so as to be sandwiched between the flange 80a on the outer surface A side and the flange 80b on the inner surface B side of the steel member 20a, and both ends 91 of the web portion 21b of the steel member 20b are connected to the web portion 21a of the steel member 20a by a method such as welding.

[0019] The square steel plate 50b on the inner surface B side of the steel plate-concrete structure 100 is arranged so as to contact and overlap with the surface on the outer surface A side of the flange 80b on the inner surface B side of the steel member 20a. Further, the flange 90b on the inner surface B side of the steel member 20b is arranged so as to contact and overlap with the surface on the outer surface A side of the steel plate 50b.

[0020] The flange 80b on the inner surface B side of the steel member 20a, the steel plate 50b, and the concrete 30 are connected by, for example, a plurality of stud bolts 70 arranged side by side in the direction along the steel member 20a. At the corner of the steel plate-concrete structure 100, the flange 90b of the steel member 20b, the steel plate 50b, and the flange 80a of the steel member 20a are arranged in this order from the outer surface A side, and are connected by bolt tightening with the stud bolt 70. Note that they may be configured to be connected by welding instead of the stud bolt 70.

[0021] Also, the square steel plate 50a on the outer surface A side of the steel plate-concrete structure 100 is arranged so as to contact and overlap with the surface on the outer surface A side of the flange 80a on the outer surface A side of the steel member 20a. Further, the flange 90a on the outer surface A side of the steel member 20b is arranged so as to contact and overlap with the surface on the inner surface B side of the flange 80a on the outer surface A side of the steel member 20a.

[0022] The flange 90a on the outer surface A side of the steel member 20b, the steel plate 50a, and the concrete 30 are connected by bolt tightening with a plurality of stud bolts 60 arranged side by side in the direction along the steel member 20b. Note that they may be configured to be connected by welding instead of the stud bolt 60.

[0023] In the steel plate concrete structure 100, the concrete 30 is filled from the outer surface A side of the steel plate 50b upwards to the surface (outer surface A side) of the flange 80a (outer surface A side) of the steel member 20a. That is, the position 40b of the back surface of the concrete 30 coincides with the outer surface A side of the steel plate 50b, and the position 40a of the front surface coincides with the front surface (outer surface A side) of the flange 80a (outer surface A side) of the steel member 20a.

[0024] As described above, the steel plate concrete structure 100 consists of steel members 20a and 20b arranged on the outer periphery of rectangular steel plates 50a and 50b, with flanges provided along the steel plates 50a and 50b, and concrete 30 filled in the space defined by the steel plates 50a and 50b and the steel members 20a and 20b, with the steel plates 50a and 50b and the steel members 20a and 20b connected at flanges 80a, 80b, 90a, and 90b.

[0025] Figures 4 to 6 show an example of the manufacturing procedure for a steel plate concrete structure.

[0026] (Procedure 1: Figure 4) In the manufacture of the steel plate concrete structure 100, first, a pair of steel members 20a that will become beams are prepared and placed parallel to each other with their web portions 21a facing each other and spaced apart.

[0027] (Procedure 2: Figure 4) On the upper surface of the steel plate 50b, a pair of steel members 20b that will serve as beams are placed parallel to each other with their web portions 21b facing each other and spaced apart. The structure 101 is then created by fastening (or welding) the flanges 90b of the steel plate 50b and the steel members 20b with stud bolts 60.

[0028] Furthermore, within a distance Dm (half the width of the flange 80a of the steel member 20a) from the end 91 of the steel member 20b, stud bolts 60 are not placed to prevent contact between the stud bolts 60 on the steel member 20b side and the flange 80b of the steel member 20a, which would hinder the insertion work during the sliding insertion of the structure 101 between the steel members 20a (see step 3 below).

[0029] (Step 3: Figure 5) Slide the structure 101 (two steel members 20b and steel plate 50b) between the two steel members 20a prepared in Step 1 and between the flanges 80a and 80b.

[0030] (Procedure 4: Figure 5) The steel plate 50b and the flange 80b of the steel member 20a are connected by fastening (or welding) stud bolts 70. At this time, at the overlapping positions of the flange 80b of the steel member 20a, the flange 90b of the steel member 20b, and the steel plate 50b in the 100mm corner of the steel plate concrete structure, these are connected by fastening stud bolts 70.

[0031] It is preferable to pre-prepare the necessary bolt holes (omitted from the drawing for simplicity) in the required parts of the steel plate 50b and steel member 20a. If it is not possible to thread the bolt holes, nuts may be used for fastening with the stud bolts 70.

[0032] (Procedure 5: Figure 5) Both ends 91 of the steel member 20b are connected to the web portion 21a of the steel member 20a that they come into contact with by welding.

[0033] (Procedure 6: Figure 5) Stud bolts 60 and 70 are installed on the flanges 80a and 90a on the upper side (outer side A) of the steel members 20a and 20b. One method of installing the stud bolts 60 and 70 is to create threaded bolt holes in the flanges 80a and 90a and insert the stud bolts 60 and 70 into them. Alternatively, through holes without threads are made in the flanges 80a and 90a, and nuts with threaded holes are fixed to the inner side B by spot welding before inserting the stud bolts 60 and 70.

[0034] (Procedure 7: Figure 6) A backing plate 110 is welded to the space created by the step difference between the upper surface of the flange 80a of steel member 20a and the upper surface of the flange 90a of steel member 20b, so that the heights of the upper surface of the flange 80a of steel member 20a and the upper surface of the flange 90a of steel member 20b are aligned.

[0035] (Procedure 8: Figure 6) Concrete 30 is poured into the space 120 defined by the steel members 20a, 20b (including the backing plate 110) and the steel plate 50b, and before the concrete 30 hardens, the steel plate 50a is placed on the upper surface of the space 120. At this time, bolt holes are pre-made in the steel plate 50a at positions corresponding to the stud bolts 60, 70 provided in the flanges 80a, 90a of the steel members 20a, 20b in Procedure 4, and the steel plate 50a is fixed by passing the stud bolts 60, 70 through the steel plate 50a with nuts.

[0036] Furthermore, if the steel member 20a is sufficiently long in the axial direction, other steel plate concrete structures can be manufactured continuously adjacent to the area where the steel plate concrete structure 100 was manufactured in the axial direction. The procedure is shown below.

[0037] (Procedure 9: Figure 4) A steel member 20b, which will serve as a beam, is placed on one end of the upper surface of a separately prepared steel plate 50b (opposite the side from the manufactured steel plate concrete structure), and the flange 90b of the steel member 20b is fastened (or welded) to the steel plate 50b and the flange 90b of the steel member 20b with stud bolts 60 to create the structure 102.

[0038] Furthermore, within a distance Dm (half the width of the flange 80a of the steel member 20a) from the end 91 of the steel member 20b, stud bolts 60 are not placed to prevent contact between the stud bolts 60 on the steel member 20b side and the flange 80b of the steel member 20a, which would hinder the insertion work during the sliding insertion of the structure 102 between the steel members 20a (see step 10 below).

[0039] (Procedure 10: Corresponding to Figure 5) The structure 102 (steel members 20b and steel plates 50b) is slid into place between the two steel members 20a and between the flanges 80a and 80b after the steel plate concrete structure 100 has been created in steps 1 to 8.

[0040] (Procedure 11: Equivalent to Figure 5) The steel plate 50b of structure 102 and the flange 90b of the steel member 20b of the manufactured steel plate concrete structure 100 are connected by fastening (or welding) stud bolts 70. Also, the steel plate 50b and the flange 80b of the steel member 20a are connected by fastening (or welding) stud bolts 70. At this time, at the overlapping positions of the flange 80b of the steel member 20a, the flange 90b of the steel member 20b, and the steel plate 50b at the corner of the steel plate concrete structure 100, these are connected by fastening stud bolts 70.

[0041] As described above, the first steel plate concrete structure 100 is manufactured by first performing steps 1 to 8, and thereafter, by repeating steps 9 to 11 and steps 5 to 8, multiple steel plate concrete structures can be continuously installed in the area sandwiched between the two steel members 20a.

[0042] Furthermore, by arranging multiple steel members 20a in parallel and repeating the above procedure, a steel plate concrete (SC) structure can be manufactured that forms a single flat plate shape, such as the roof structure 10 shown in Figure 1.

[0043] The above manufacturing procedure exemplifies the process of sequentially completing a steel plate concrete (SC) structure in the smallest unit area. However, for example, steps 1 to 3 and steps 9 to 10 may be carried out first to complete the framework, and then steps 4 and 11 onwards, such as welding and concrete pouring, may be carried out all at once.

[0044] Furthermore, although this embodiment describes the steel plate concrete (SC) structure as being in a flat plate shape, it is also possible to give the steel plate concrete (SC) structure curvature by, for example, pre-shaping the steel members 20a, 20b or the steel plates 50a, 50b into an arch shape. In this case, it is necessary to match the curvature so that no snagging or other problems occur when inserting the structures 101, 102.

[0045] Furthermore, in this embodiment, the connection between the steel members 20a, 20b and the steel plates 50a, 50b is illustrated by bolt fastening using stud bolts 60, 70, but welding may be used instead of bolt fastening.

[0046] Furthermore, although this embodiment has described the case in which a steel member 20b similar to a so-called H-beam is used individually, it is not limited to this. For example, multiple H-beam type steel members may be arranged adjacently so that their web portions (faces) are located within a single virtual plane, and the flange portions may be connected by bolting or welding to form a steel member 20b.

[0047] The effects and advantages of this embodiment, configured as described above, will now be explained.

[0048] The new regulatory standards for nuclear power plants, established after the Fukushima Daiichi nuclear power plant accident, require that the reactor be safely shut down and maintained in a cold shutdown state even in the event of terrorist acts such as the intentional collision of heavy objects or high-speed flying objects like aircraft or missiles with the reactor building. One design policy for cold shutdown of the reactor in the event of a heavy object collision is to design the exterior walls of the reactor building to be robust so that they do not penetrate even when heavy objects collide with it. In order to prevent the exterior walls from penetrating the large impact loads of a heavy object collision, it is conceivable to use a steel plate reinforced concrete (SC) structure, which has higher impact resistance than reinforced concrete (RC) structures, and to design the wall thickness to be thicker.

[0049] A steel plate concrete structure is a structure in which concrete is filled in a region sandwiched between steel plates, and has a different structure from a reinforced concrete structure in which reinforcing bars are placed inside the concrete. For example, in a reinforced concrete structure, the reinforcing bars installed inside the concrete bear the tensile load, and the concrete bears the compressive load. On the other hand, in a steel plate concrete structure, the steel plates bear the tensile load instead of the reinforcing bars, and the concrete bears the compressive load. In addition, in a reinforced concrete structure, a wave-shaped pattern is provided on the surface of the reinforcing bars to ensure fastening between the reinforcing bars installed inside the concrete and the concrete. On the other hand, in a steel plate concrete structure, stud bolts are provided on the inner surface of the steel plates to ensure sufficient contact between the steel plates installed on the surface of the concrete and the concrete, and to allow the steel plates and concrete to behave as one unit, and these stud bolts are used to fasten them to the concrete.

[0050] In a steel plate concrete structure, concrete is sandwiched between steel plates. Therefore, even if the concrete delaminates on the back surface, the concrete fragments can be retained inside as long as the steel plates do not break. For this reason, in locations where delamination on the back surface is undesirable, steel plate concrete is more suitable as a protective wall than reinforced concrete.

[0051] Furthermore, in steel plate concrete structures, since the steel plates are installed on the surface of the concrete, the distance from the central axis to the steel plates is long, resulting in a large moment due to the tensile load from the steel plates during bending deformation. This is evident from the fact that in reinforced concrete, the "cover," which is the concrete placed on the surface side of the reinforcement, does not resist the tensile load during bending deformation. In other words, in steel plate concrete structures, all of the concrete sandwiched between the steel plates becomes the effective volume, and for the same wall thickness, the effective volume can be made larger compared to reinforced concrete structures, thus increasing impact resistance. Therefore, it is useful to apply steel plate concrete structures to the exterior walls and ceilings of buildings to use them as protective structures against flying objects. However, if the impact load from flying objects is large and cracks occur in the fastening between the stud bolts and the concrete, there is a high possibility that the stud bolts will separate from the concrete.

[0052] Figure 9 shows a comparative example of a conventional steel plate concrete structure. As shown in Figure 9, on the back side opposite the impact surface (front side), if bending deformation occurs due to the impact of a flying object, tensile stress will be generated on the concrete surface, causing cracks in the concrete, and it is expected that the stud bolts will become more likely to come loose as a result of the cracks. If the fastening between the steel plate and the concrete comes undone on the back side, the effect of the steel plate in bearing the tensile load will be significantly reduced, and it is expected that the concrete will be subjected to a tensile load, causing it to break, and consequently the steel plate concrete structure to collapse.

[0053] To prevent cracking of the concrete on the back side and the resulting pulling out of the stud bolts when subjected to impact loads, increasing the thickness of the steel plate concrete is a possible solution. However, increasing the wall thickness also increases the weight of the steel plate concrete structure. Therefore, especially when a steel plate concrete structure is applied to the ceiling of a building, the weight of the upper part of the building increases, reducing the building's seismic resistance.

[0054] In contrast, in this embodiment, the structure consists of a rectangular steel plate 50b, steel members 20a and 20b arranged on the outer periphery of the steel plate 50b and having flanges 80b and 90b provided along the steel plate 50b, and concrete 30 filled in the space defined by the steel plate 50b and the steel members 20a and 20b. The steel plate concrete structure is configured such that the steel plate 50b and the steel member 20a are connected at the flange 80b, thus improving impact resistance without increasing the wall thickness.

[0055] Figures 7 and 8 are enlarged views of a portion of the steel plate concrete structure according to this embodiment shown in Figure 3. Figure 7 shows the structure under normal conditions, while Figure 8 shows the structure during an impact by an incoming object.

[0056] As shown in Figures 7 and 8, the steel plate 50b, which is positioned on the inside side (inner surface B) of the building, is positioned on the inside (inner surface B) of the flange 80b of the steel member 20a. As shown in Figure 8, in the event of a collision with an incoming object, the load that causes the steel plate 50b and the concrete 30 to deform downwards is supported not only by the stud bolts 70 but also by the flange 80b of the steel member 20a. As also shown in Figure 9 (comparative example), a large bending deformation occurs on the back side opposite to the impact surface when an incoming object collides with it. However, in this embodiment, the steel plate 50b is also supported by the flange 80b of the steel member 20a, so the amount of bending deformation on the back side can be reduced. This reduces the occurrence of cracks in the concrete portion where the stud bolts 70 are fastened and prevents the steel plate 50b on the back side from separating from the concrete 30.

[0057] In this embodiment of the steel plate concrete structure 100, when the lengths of the steel members 20a and 20b are different (i.e., when the steel plate concrete structure 100 is rectangular), the steel member 20a is positioned on the longer side and the steel member 20b is positioned on the shorter side. This increases the support area of ​​the flange 80b of the steel member 20a relative to the steel plate 50b on the inside of the building (inner surface B side), thereby increasing the support load of the flange 80b.

[0058] <Other> It should be noted that the present invention is not limited to the embodiments described above, and includes various modifications that do not depart from the spirit of the invention. For example, the present invention is not limited to having all the configurations described in the embodiments described above, but also includes configurations in which some of those configurations are omitted. Furthermore, it is possible to add or replace a part of the configuration of one embodiment with a configuration of another embodiment. [Explanation of Symbols]

[0059] 10...Roof structure, 11...Exterior wall structure, 20a, 20b...Steel members, 21a, 21b...Web section, 30...Concrete, 40a, 40b...Face position, 50a, 50b...Steel plate, 60, 70...Stud bolt, 80a, 80b, 90a, 90b...Flange, 91...End section, 100...Steel plate concrete structure, 101, 102...Structure, 110...Backing plate, 120...Space

Claims

1. A rectangular steel plate, A steel member having a flange provided along the outer circumference of the steel plate, It consists of concrete filled in the space defined by the steel plate and the steel member, A steel plate concrete structure characterized in that the steel plate and the steel member are connected at least at the flange.

2. In the steel plate concrete structure according to claim 1, A steel plate concrete structure characterized in that at least two of the four sides of the steel plate are positioned inside the flange of the steel member.

3. In the steel plate concrete structure according to claim 1, The steel plate concrete structure is characterized in that the steel member is composed of a plurality of steel plate members connected in the thickness direction of the steel plate concrete structure.

4. In the steel plate concrete structure according to claim 1, The steel plate has a rectangular shape, A steel plate concrete structure characterized in that two of the long sides of the steel plate are positioned inside the flange of the steel member.

5. In the steel plate concrete structure according to claim 2 or 4, The steel plate concrete structure is characterized in that the steel plate is composed of a pair of steel plates arranged on the front and back surfaces of the steel plate concrete structure, and the steel plate arranged on the back surface is positioned inside the flange of the steel member.

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