Installation structure and construction method for additional reinforcing frame framework.

Abstract

To provide an attachment structure for an additional reinforcement frame and a construction method thereof with which reinforcement work can be carried out without necessity to remove fence walls in corridors, etc., continuity of residence is possible during construction, orthogonal beams that are not bulky, nor become an obstacle overhead are realized after completion, providing a feeling of peace for those going back and forth, furthermore, the orthogonal beams and a seismic reinforcement structure surface can be made smaller, and the amount of construction work can be reduced.SOLUTION: A steel orthogonal beam 56, which is a vertically asymmetrical deformed welded H-beam 56H and extends perpendicularly to the girder direction of an existing building 1AA, with a flange portion 6f along a lower inclined surface 5u of a floor slab 55 forming a public corridor BB, is provided from the intersection of an existing column 33C and an existing beam 33B of an existing structure surface 33. A space 8 surrounded with the existing column 33C, the existing beam 33B, a steel reinforced column 44C, a steel reinforced beam 44B, the deformed welded H-beam 56H, an adjacent deformed welded H-beam 56H, and the lower inclined surface 5u of the floor slab 55 becomes an additional slab equipped with shear reinforcement bars 9R.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a dressing structure of an additional reinforcement frame structure. More specifically, it relates to a dressing structure body of an additional reinforcement frame structure that integrates a seismic reinforcement surface on which braces can be attached to an existing surface on the lower side of a shared corridor of an apartment house with RC or SRC construction, and a construction method thereof.

Background Art

[0002] In apartment houses with RC (reinforced concrete structure) or SRC (steel reinforced concrete structure) construction, seismic walls are formed in the span direction, that is, the short side direction, and a ramen structure is adopted in the girder direction to secure openings such as entrances and windows. When performing seismic reinforcement on such existing buildings, a proposal for a structure that integrates a seismic reinforcement surface on the existing surface on the lower side of the shared corridor extending in the girder direction is described in, for example, Patent Document 1.

[0003] As shown in FIG. 10, the seismic reinforcement surface 44 is provided separately from the existing surface 33 via a reinforcement slab 55R (see the lower half of FIG. 10) integrated with the lower surface of the shared corridor BB and an orthogonal beam 66 (see the upper half of FIG. 10) provided at substantially the same level at the door boundary of that floor. Therefore, it will be installed outside the shared corridor BB. Therefore, since the seismic reinforcement surface 44 is not subject to the restrictions of providing openings such as entrances and windows, as shown in FIG. 11, even though brace members 64 and gusset plates 65 act to obscure the view and make the space of the shared corridor BB dim and reduce the view during walking, there is an advantage that the degree of freedom when attaching braces to the seismic reinforcement surface 44 (for example, the freedom to select the brace form) is improved.

[0004] If the existing surface 33 (see FIG. 10) is RC or SRC construction, the seismic reinforcement surface 44 is also RC or SRC construction (for example, see Patent Document 2), and inevitably, the orthogonal beam 66 (see the upper half of FIG. 10) also adopts RC or SRC construction.

[0005] If the orthogonal beam 66 is constructed of reinforced concrete (RC) or steel-reinforced concrete (SRC), the base end 66b and the tip end 66e require high anchorage for the reinforcing bars 67 embedded in the orthogonal beam 66 (see the upper half of Figure 10) when they are integrated with the existing structural plane 33 or the seismic reinforcement structural plane 44. Of course, high anchorage is also required for the shear reinforcement bars 67S embedded in the reinforcing slab 55R (see the lower half of Figure 10) formed beneath the common corridor BB. Incidentally, the upper 69 in Figure 10 is a post-installed anchor for integrating the floor slab 55 and the orthogonal beam 66, and the lower 69 in Figure 10 is a post-installed anchor for integrating the floor slab 55 and the reinforcing slab 55R (for the sake of comparison, Figure 10 depicts the vertical plane of the orthogonal beam 66 and the vertical plane of the reinforcing slab 55R as being on the same vertical plane).

[0006] To enhance the anchoring effect, both ends of the reinforcing (main) bars 67 of the orthogonal beam 66 must be significantly embedded in or bent into the existing structural plane 33 or the seismic reinforcement structural plane 44, as shown in Figure 12, which is an enlarged view of only the orthogonal beam 66. This necessitates a modification that increases the volume of the joint with the existing structural plane 33. Furthermore, the joint with the seismic reinforcement structural plane 44 will also involve a significant increase in volume, making the temporary removal of the handrail fence 68 (see also Figure 10) or fence parapet of the common corridor BB unavoidable. As a result, passage will either be prohibited, or even if passage is permitted, it will inevitably cause a sense of insecurity underfoot. Ultimately, a considerable number of residents will be forced to vacate their homes during the construction. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2012-1922 [Patent Document 2] Japanese Patent Publication No. 2015-196942 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Despite the disadvantages and inconveniences described above, the introduction of orthogonal beams is essential for seismic reinforcement. Orthogonal beams are mainly installed at the partitions between units in the common corridor BB, but construction work to integrate them with the floor slab 55 that makes up the common corridor BB is also required. To withstand the bending forces acting on the orthogonal beams, the second moment of area and section modulus must be large, and in particular, a sufficiently large cross-sectional area is required in the direction perpendicular to the plane of the paper.

[0009] Incidentally, when installing an additional reinforced frame structure made of RC or SRC, if we compare the reinforcing slab 55R (see the lower half of the slab in Figure 10), which is installed between the partitions of units to reinforce the floor slab 55 and share horizontal forces, with the orthogonal beam 66 (see the upper part of Figure 10), which is installed at the partitions of units, the latter, which is deliberately drawn superimposed, is bulkier, and the difference in its vertical dimensions is immediately apparent (the upper 31 in Figure 10 indicates the lower edge of the orthogonal beam 66, while the lower dashed line 31 in Figure 10 indicates the hypothetical lower edge of the orthogonal beam 66. On the other hand, the upper dashed line 32 in Figure 10 represents the hypothetical lower edge of the reinforcing slab 55R). When moving through the corridor after completion, even if the reinforcing slab 55R installed between the partitions of units is not a concern, attention must be paid to the overhead of the orthogonal beam 66 installed at each partition, making the use of the common corridor BB inconvenient. This results in a significant decrease in livability.

[0010] The present invention has been made in view of the above circumstances, and its purpose is to provide a mounting structure for an additional reinforcing frame structure and a method for constructing it, which enables reinforcement work without the need to remove corridor fences or parapets, allows continued residence during construction, provides a compact orthogonal beam that does not become an overhead obstruction after completion, provides a sense of security for those passing through, and enables miniaturization of the orthogonal beam and seismic reinforcement structure, and consequently reduces the amount of construction work. [Means for solving the problem]

[0011] The features of the present invention are, as shown in Figure 1, in an additional reinforcing frame structure for an RC or SRC apartment building where the short side direction is a seismic wall and the girder direction is a rigid frame structure, and an additional reinforcing frame structure for which a seismic reinforcement surface 44 to which braces can be attached is integrated with the existing structural surface 33 on the common corridor BB side extending in the girder direction of the existing building 1AA, From the intersection of the existing columns 33C and existing beams 33B of the existing structural plane 33, a steel orthogonal beam 56, which is an asymmetrical deformed welded H-shaped steel 56H extending perpendicular to the girder direction of the existing building 1AA, is positioned with its flange portion 56f along the inclined lower surface 5u of the floor slab 55 forming the common corridor BB. As shown in Figure 2, a headed stud 7 is welded to the web portion 56w of the deformed welded H-beam 56H, projecting horizontally toward the space beneath the floor slab 55. The base end 56b of the deformed welded H-beam 56H is integrated with the existing column 33C of the existing structural plane 33, while the tip end 56e is integrated with the reinforcing column 44C of the seismic reinforcement structural plane 44. The seismic reinforcement structure 44 is a steel frame structure, The space 8 enclosed by the existing column 33C, existing beam 33B, steel reinforcing column 44C, steel reinforcing beam 44B, deformed welded H-beam 56H, another adjacent deformed welded H-beam 56H, and the lower inclined surface 55u of the floor slab 55 is made into an additional slab equipped with shear reinforcement bars 9R (see Figure 3).

[0012] As shown in Figure 2, the base end 56b of the deformed welded H-beam 56H is integrated with the existing column 33C by adhesive anchor bolts 11, while the tip end 56e is integrated with the reinforcing column 44C by friction jointing through high-strength bolts 6 via splice plates 13 to a vertical bracket 12 attached to the reinforcing column 44C.

[0013] As shown in Figure 9, when PC panels 18 are attached to the outer surfaces of existing columns 33C and existing beams 33B in an apartment building, the additional slab 84, which is at approximately the same level as the orthogonal beam 56 at the partition between units, is integrated with the existing structural surface 33 via an indirect joint 20 that includes the head 19h of a thick-walled steel pipe shackle 19, which has a leg portion 19f that penetrates the PC panel 18 and is embedded and fixed in the existing beam 33B.

[0014] As shown in Figures 5 and 6, the brace that can be attached to the additional reinforcing frame 44 is a cross brace mechanism 25 (see Figure 6) made of two half-width flat steel plates fitted into the space 34 (see Figure 5) surrounded by the reinforcing column 44C and the reinforcing beam 44B.

[0015] In the invention of the method for constructing an additional reinforcing frame frame structure as described above, a bottom plate formwork 26 (see Figure 2) is placed on the surface corresponding to the bottom of the surrounding space 8, and an additional slab 84 can be formed by injecting high-flow, non-shrinking, high-strength mortar 28 or high-flow, non-shrinking, high-strength concrete into the surrounding space 8 through injection holes 27 that penetrate the floor slab 55 vertically until it flows out through air vent holes 29 that penetrate the floor slab 55. [Effects of the Invention]

[0016] According to the present invention, since the seismic reinforcement structure is made of steel, the orthogonal beams can also be made of steel for ease of connection. Since the orthogonal beams are deformed welded H-shaped steel with an asymmetrical top and bottom, the flange portion can be easily aligned with the inclined surface of the floor slab forming the common corridor. Furthermore, because they are made of steel, the degree of freedom in shape selection due to the top and bottom asymmetry is increased, and it is not necessary to make the second moment of area and section modulus as large as those of orthogonal beams made of reinforced concrete or steel-reinforced concrete. Therefore, the need to take precautions to avoid bumping one's head when passing through the corridor is minimized, and a compact orthogonal beam that does not obstruct the view is realized.

[0017] Avoiding the use of reinforced concrete (RC) or steel-reinforced concrete (SRC) for orthogonal beams promotes a lower building volume, eliminating concerns about residents' mobility and the need to remove fences that would force them to temporarily vacate the premises. This also allows residents to continue living in the building during construction.

[0018] Since the base end of the orthogonal beam and the existing structure surface are integrated by adhesive anchor bolts, the construction can be simplified compared to the case of adopting reinforcing bars with high fixing performance in mind. On the other hand, the protruding end of the orthogonal beam is integrated with the reinforcing column by fastening high-strength bolts via a splice plate to a vertically positioned bracket attached to the reinforcing column, so that a highly stable friction joint form can be achieved.

[0019] Even in the case of an apartment building where PC boards (precast concrete panels) are adhered to the outer surfaces of the existing columns and existing beams, an indirect joint part including the head of a thick steel pipe shear key having legs penetrating through the PC board and embedded and fixed in the existing beam can be formed. If integration is achieved through this indirect joint part, the additional slab can have a highly stable support structure on the existing structure surface.

[0020] If the brace that can be attached to the additional reinforcement frame is set as a cross brace mechanism of half-width double-plate flat steel plates fitted into the space surrounded by the reinforcing column and the reinforcing beam, it is a brace that is mechanically equivalent to a double-width brace that obstructs the view, but significantly improves the view from the shared corridor.

[0021] Even in the above-mentioned additional reinforcement frame structure dressing structure body, a formwork bottom plate is arranged on the surface hitting the bottom of the surrounding space, and highly fluid non-shrinking high-strength mortar or highly fluid non-shrinking high-strength concrete is injected into the surrounding space from the injection holes penetrating the floor slab up and down until it flows out from the air vent holes penetrating the floor slab, thereby forming an additional slab. After the additional slab is cured and solidified, it is only necessary to remove the formwork bottom plate, and the surrounding steel frame members serve as a substitute for the formwork, significantly saving the labor of removing the formwork.

Brief Description of the Drawings

[0022] [Figure 1] Overall view of an embodiment of the dressing structure of the additional reinforcement frame structure according to the present invention. [Figure 2] Enlarged view of an orthogonal beam made of deformed welded H-shaped steel with upper and lower asymmetry. [Figure 3] Overhead view of the orthogonal beam and the additional slab. [Figure 4] Diagram illustrating the stresses on orthogonal beams caused by horizontal forces acting on the floor slab and extension slab. [Figure 5] Side view of a cross brace mechanism made of two half-width flat steel plates joined together. [Figure 6] Front view of a cross brace mechanism made of two half-width flat steel plates joined together. [Figure 7] A conceptual diagram showing how the view is improved by applying an additional reinforcing frame structure with a cross bracing mechanism made of two half-width flat steel plates joined together. [Figure 8] An overhead view of a reinforced slab in which thick-walled steel pipe shears have been introduced by attaching PC panels to the seismic reinforcement structure. [Figure 9] Enlarged structural diagram of an extension slab to which thick-walled steel pipe shears are applied. [Figure 10] A diagram showing the layout of a corridor when the orthogonal beams are made of reinforced concrete (RC) or steel-reinforced concrete (SRC). [Figure 11] A conceptual diagram illustrating the poor visibility when a cross-bracing mechanism using a single, full-width flat steel plate is applied to a seismic reinforcement structure. [Figure 12] Enlarged view of the internal structure of orthogonal beams in reinforced concrete (RC) or steel-reinforced concrete (SRC) construction. [Modes for carrying out the invention]

[0023] The following describes in detail the mounting structure for the additional reinforcing frame structure according to the present invention and its construction method, based on drawings illustrating embodiments. This invention is a mounting structure for an additional reinforcing frame structure that integrates a seismic reinforcing frame surface, which can be fitted with braces (not shown), with an existing frame surface on the side of a common corridor extending in the girder direction of an existing building, where the short side direction is a seismic wall and the girder direction is a rigid frame structure, as shown in Figure 1.

[0024] The additional reinforcing frame structure is positioned on the outside of the common corridor, allowing for the installation of seismic reinforcement braces without affecting openings such as entrances and windows. This also minimizes the size of the orthogonal beams required for this purpose, ensuring safety in the corridor during construction and eliminating the need for temporary removal and reinstallation of corridor handrails, thus enabling continued occupancy during construction. The seismic reinforcement structure 44 can accommodate various types of braces, such as X-shaped, V-shaped, and K-shaped braces, and in particular, an innovative narrow X-shaped brace, which will be discussed in more detail later, that does not obstruct the view.

[0025] The narrow X-shaped brace is the cross brace mechanism 25 made of two laminated flat steel plates proposed by the inventor in Japanese Patent Application No. 2021-69387 (see Figures 5 and 6), and will be explained later with an example of its adoption.

[0026] As shown in Figure 1, a steel orthogonal beam 56, which is an asymmetrical deformed welded H-shaped steel beam 56H, is installed from the intersection of the existing column 33C and existing beam 33B of the existing structural plane 33, with its upper flange portion 56f aligned with the lower inclined surface 55u of the floor slab 55 forming the common corridor BB shown in Figure 2, and extending perpendicular to the existing building 1AA. The intersection of the existing column 33C and existing beam 33B of the existing structural plane 33 means from the height level of the existing beam 33B at the existing column 33C that forms the partition between units on the common corridor BB side, and the orthogonal beam means that it extends horizontally perpendicular to the girder direction of the existing building 1AA.

[0027] This welded H-beam 56H is not a roll-formed H-beam, which is created by passing a billet through multiple rolling rolls on a rolling line to gradually deform it into an H-shape. Instead, it is a steel frame obtained by cutting and deforming flat steel into the desired shape in a metal fabrication plant, and then welding it into an H-shape. Therefore, it is a steel material whose shape and dimensions can be freely selected, without being constrained by JIS standards such as roll-formed steel. Consequently, it is asymmetrical, meaning the cross-sectional shape and dimensions are not necessarily fixed, and the flange can be inclined or bent instead of flat. Of course, it is also easy to make the web shape match the non-flat flange.

[0028] A headed stud 7 (see also Figure 3) is welded to the web portion 56w of this deformed welded H-beam 56H, projecting horizontally toward the space beneath the floor slab 55, ensuring a secure connection with the additional slab 84 described later. In the case of deformed welded H-beams (not shown) located at the very ends of a building where the floor slab 55 is not present on both sides (top and bottom in Figure 3), the headed stud is welded to only one side of the web portion.

[0029] Returning to Figure 2, the base end 56b of the deformed welded H-beam 56H is integrated with the existing column 33C of the existing structural plane 33, while the tip end 56e is integrated with the reinforcing column 44C of the seismic reinforcement structural plane 44. Incidentally, the existing column 33C of the existing structural plane 33 extends vertically, and the existing beam 33B is located between the existing column 33C, transmitting the force supporting the floor on each floor to the existing column 33C. The reinforcing column 44C of the seismic reinforcement structural plane 44 also extends vertically across floors via flange joints (not shown), and the reinforcing beam 44B is located between the reinforcing column 44C, connected via flange joints 30 (see Figure 3), etc., and transmitting the force supporting the load on each floor to the reinforcing column 44C. In other words, all vertical loads acting on the seismic reinforcement structure 44 are indirectly transmitted via the reinforcing columns 44C to a newly constructed foundation (not shown) directly below them, or to the foundation directly below the existing columns 33C, through members not shown.

[0030] Incidentally, the base end 56b of the deformed welded H-beam 56H is integrated with the existing column 33C by adhesive anchor bolts 11 (see Figure 2), while the tip end 56e is integrated with the reinforcing column 44C by a friction joint configuration using high-strength bolts 6 fastened via a splice plate 13 to a vertical bracket 12 attached to the reinforcing column 44C. Note that 12A is a backup stiffener.

[0031] The existing beam 33B is integrated with the existing column 33C using reinforced concrete or steel-reinforced concrete, while the reinforcing beam 44B is welded to the reinforcing column 44C. As can be seen from this, the seismic reinforcement structure 44 is pre-assembled in subassembly near the construction site and then lifted up using a crane or similar method.

[0032] Once the steel frame assembly is complete, an additional slab (horizontal diaphragm) 84 (see Figure 3) integrated with the orthogonal beam 56 is formed beneath the floor slab, thereby increasing the floor slab's resistance to horizontal forces while also achieving high rigidity for the orthogonal beam 56. Then, a bottom plate formwork 26 (see Figure 2) is placed on the bottom surface of the space 8 surrounded by the existing columns 33C, existing beams 33B, reinforcing columns 44C, reinforcing beams 44B, deformed welded H-beams 56H, and other adjacent deformed welded H-beams 56H, and is supported by scaffolding, etc. Shear reinforcement bars 9R and spiral hoops 85 (see Figure 3) are placed in space 8, and once the space for the additional slab 84 is formed, high-flow, non-shrinkage, high-strength mortar (e.g., 40 N / mm²) is injected into the surrounding space 8 through injection holes 27 (see Figure 2) that penetrate the floor slab 55 vertically. 2 The additional slab 84 is formed by injecting (as described above) 28 or high-flow, non-shrinking, high-strength concrete (see Japanese Patent Publication No. 2003-89563) until it flows out through the air vents 29 penetrating the floor slab 55. It should be noted that the existing columns 33C, existing beams 33B, reinforcing columns 44C, reinforcing beams 44B, deformed welded H-shaped steel 56H, and other adjacent deformed welded H-shaped steel 56H serve as formwork for pouring the high-flow, non-shrinking concrete, and it is understood that there is no need to install or remove formwork other than the bottom plate 26.

[0033] With this configuration, since the seismic reinforcement structure 44 is made of steel, the orthogonal beam 56 can also be made of steel as described above for ease of connection. Since the orthogonal beam is a deformed welded H-shaped steel 56H with an asymmetrical top and bottom, the upper flange portion 56f can be easily aligned with the lower inclined surface 55u of the floor slab 55 that forms the common corridor BB. Because it is made of steel, there is a high degree of freedom in selecting the shape due to the asymmetrical top and bottom, and it is not necessary to make the second moment of area and section modulus as large as those of orthogonal beams made of reinforced concrete or steel-reinforced concrete. Therefore, the need to take precautions to avoid bumping one's head when passing through the corridor is minimized, and a compact orthogonal beam that does not obstruct the view from the front is realized.

[0034] Since the orthogonal beams are made of steel, it becomes easy to integrate the base end 56b and tip end 56e of the orthogonal beams with the existing structural surface 33 or the steel seismic reinforcement structural surface 44, which promotes weight reduction and shortening of construction time for the seismic reinforcement structural surface 44.

[0035] A headed stud 7 is welded to the web portion 56w of the deformed welded H-beam 56H, projecting horizontally toward the space beneath the floor slab 55. This ensures a rigid connection between the deformed welded H-beam 56H and the additional slab 84, and contributes to the compact design of the deformed welded H-beam 56H.

[0036] Avoiding the use of reinforced concrete (RC) or steel-reinforced concrete (SRC) for the orthogonal beam 56 promotes a lower volume, eliminating concerns about residents' mobility and the need to remove fences that would force temporary relocation, thus allowing residents to continue living in the building during construction. Since the base end 56b of the orthogonal beam and the existing structural plane 33 are integrated by adhesive anchor bolts 11, the construction is simplified compared to when reinforcing bars are used with high anchorage in mind. On the other hand, the tip end 56e of the orthogonal beam is integrated with the reinforcing column 44C by fastening a high-strength bolt via a splice plate 13 to a vertical bracket 12 attached to the reinforcing column 44C, thus enabling a highly stable friction joint configuration.

[0037] Even in the above-mentioned additional reinforcement frame frame structure, an additional slab 84 can be formed by placing a formwork bottom plate 26 on the surface corresponding to the bottom of the surrounding space 8 and injecting high-flow, non-shrinking, high-strength mortar 28 into the surrounding space 8 through injection holes 27 that penetrate the floor slab 55 vertically. After the additional slab 84 has cured and hardened, only the formwork bottom plate 26 needs to be removed, and the surrounding steel members act as formwork, greatly reducing the effort required to remove the formwork.

[0038] Incidentally, as shown in Figure 4, when a horizontal force 11A acts on the floor slab 55 due to an earthquake or the like, a moment 11M is generated. To counteract this moment 11M, a force 11a is generated in the orthogonal beam 56 that generates a moment. The slab to the right also generates a similar force 11b in the opposite direction on the orthogonal beam 56, so they cancel each other out and ultimately no large force acts on the orthogonal beam. This behavior also applies to orthogonal beams in reinforced concrete structures, but only when there are slabs on both sides. If there is only a slab on one side, it is unavoidable that a large force acts on the orthogonal beam in the longitudinal direction. The orthogonal beam needs to withstand this force 11a, and countermeasures are necessary for orthogonal beams in reinforced concrete structures. On the other hand, it is quite easy to give the deformed welded H-shaped steel 56H the capacity to withstand this. To put it simply, it can withstand the force even if it is made to the same specifications as an H-shaped steel orthogonal beam with slabs on both sides, and the commonality of input materials is also demonstrated.

[0039] Incidentally, the brace that can be attached to the additional reinforcing frame 44 is a cross brace mechanism 25 (see Japanese Patent Application No. 2021-69387) made of two half-width flat steel plates fitted into a space 34 perpendicular to the plane of the paper surrounded by the reinforcing column 44C and reinforcing beam 44B shown in Figure 5. An example is a type attached to the weak axis of the reinforcing column 44C, which will be briefly described below.

[0040] Referring to Figure 6, four flat steel plates 1a, 1b, 1c, and 1d, all of the same length and thickness, are arranged in a vertical plane close to each other. A wide end plate 2, which is the same thickness as the flat steel plate 1, is joined to both ends of the flat steel plate 1 by butt welding 3, with a narrow end equal to the width of the flat steel plate. The first flat steel plate 1a intersects with the second flat steel plate 1b without making contact in an X-shape, and the third flat steel plate 1c, positioned in the same orientation as the first flat steel plate 1a, intersects with the fourth flat steel plate 1d, positioned in the same orientation as the second flat steel plate 1b, without making contact in an X-shape. The two gusset plates 4A and 4B have a thickness less than or equal to that of a flat steel and are welded to the diagonal corners of the structural plane. The first flat steel 1a and the third flat steel 1c sandwich the first gusset plate 4A and the second gusset plate 4B and are rigidly fixed together with high-strength bolts 6 between the end plates 2a1, 2c1, 2a2, 2c2, thus forming the first double flat steel brace body 5A. The other gusset plates 4C and 4D also have a thickness less than or equal to that of a flat steel and are welded to the other diagonal corners of the structural plane. The second flat steel 1b and the fourth flat steel 1d sandwich the third gusset plate 4C and the fourth gusset plate 4D and are rigidly fixed together with high-strength bolts 6 between the end plates 2b1, 2d1, 2b2, 2d2, thus forming the second double flat steel brace body 5B. Furthermore, the first brace member 5A and the second brace member 5B form a cross brace body 10 made of two flat steel plates joined together, without a gusset plate being provided at the intersection of the two brace members.

[0041] If the brace that can be attached to the additional reinforcing frame 44 is made into a cross brace mechanism 25 of two half-width flat steel plates fitted into the space 34 surrounded by the reinforcing column 44C and the reinforcing beam 44B, then it is a brace that is mechanically equivalent to a double-width brace that obstructs the view (see Figure 11), while significantly improving the view from the common corridor and eliminating the feeling of oppression (see Figure 7).

[0042] Incidentally, in apartment buildings, as shown in Figure 8, when PC panels (precast concrete panels) 18 are attached to the outer surfaces of existing columns 33C and existing beams 33B, the additional slab 84 shown in Figure 9, which is at approximately the same level as the orthogonal beam 56 at the partition between units, is integrated with the existing structure, i.e., the existing structural plane 33, via an indirect joint 20 that includes the head 19h of a thick-walled steel pipe shackle 19, which has a leg portion 19f that penetrates the PC panel 18 through an oversized hole 13a designed to prevent load transmission and is embedded and fixed in the existing beam 33B. Note that 86 is a headed stud, and 36 is mortar filled between the reinforcing steel frame 35 and the existing structure 33.

[0043] As a result, it becomes easy to install the reinforced steel frame 35 perpendicular to the RC / SRC structure, and the thick-walled steel pipe key can secure a much larger bending and shear stiffness than ordinary steel bars used as anchors, as well as a larger concrete bearing area. The large shear force acting from the structure to the indirect joint can be reliably transmitted to the reinforced steel frame. Therefore, the number of materials used for reinforcement is greatly reduced, and the amount of work and construction time saved is remarkable. Of course, construction can also be expedited. [Explanation of Symbols]

[0044] 1AA: Existing building, BB: Common corridor, 1: Flat steel, 1a: First flat steel, 1b: Second flat steel, 1c: Third flat steel, 1d: Fourth flat steel, 2, 2a1, 2a2, 2b1, 2b2, 2C1, 2C2, 2d1, 2d2: End plate, 3: Butt weld, 4: Gusset plate, 4A: First gusset plate, 4B: Second gusset plate, 4C: Third gusset plate, 4D: Fourth gusset plate, 5: Brace body, 5A: First brace body, 5B: Second brace body, 6: High-strength bolt, 7: Headed stud, 8: Enclosed space, 9R: Shear reinforcement, 10: Cross brace body, 11: Adhesive anchor bolt, 12: Bracket, 13: Splice plate, 13a: Hole, 18: PC panel (precast concrete panel), 19: Thick-walled steel pipe shackle, 19f: Leg section, 19h: Head section, 25: Cross brace mechanism of two half-width flat steel plates joined together, 18: PC panel, 19: Thick-walled steel pipe, 19: Thick-walled steel pipe shackle, 19f: Leg section, 19h: Head section, 20: Indirect joint, 21: Bracket, 22: Splice plate, 23: High-strength bolt, 25: Cross brace mechanism of two half-width flat steel plates joined together, 26: Bottom plate formwork, 27: Injection hole, 28: High-flow, non-shrinkage, high-strength mortar, etc., 29 : Air vent hole, 33: Existing structural surface, 33C: Existing column, 33B: Existing beam, 34: Enclosing space, 35: Reinforcement steel frame, 36: Mortar, 44: Seismic reinforcement structural surface, 44B: Reinforcement beam, 44C: Reinforcement column, 55: Floor slab, 55R: Reinforcement slab, 55u: Lower inclined surface, 56: Steel right-angle beam, 56H: Asymmetrical deformed welded H-beam, 56f: Flange section, 56w: Web section, 56b: Base end, 56e: Protruding end, 84: Additional slab (horizontal diaphragm), 85: Spiral hoop, 86: Headed stud,

Claims

1. In a reinforced concrete (RC) or steel-reinforced concrete (SRC) apartment building, where the short side is a shear wall and the girder direction is a rigid frame structure, an additional reinforcing frame structure is attached to an existing structural surface on the common corridor side extending in the girder direction of the existing building, to which a brace can be attached. From the intersection of the existing columns and beams of the existing structural plane, a steel orthogonal beam, which is an asymmetrical deformed welded steel section extending perpendicular to the existing building with its flange portion aligned along the inclined lower surface of the floor slab forming the common corridor, is positioned. A headed stud is welded to the web portion of the deformed welded steel section, projecting horizontally toward the space beneath the floor slab. The base end of the deformed welded steel section is integrated with the existing column of the existing structural plane, while the tip end is integrated with the reinforcing column of the seismic reinforcement structural plane. The seismic reinforcement structure is made of steel. An additional reinforced frame structure is characterized in that the space surrounded by the existing columns, existing beams, reinforcing columns, reinforcing beams, deformed welded steel sections, other adjacent deformed welded steel sections, and the inclined lower surface of the floor slab is an additional slab equipped with shear reinforcement bars.

2. The base end of the deformed welded steel section is integrated with the existing column by adhesive anchor bolts, while the tip end is integrated with the reinforcing column by friction bonding through a splice plate and high-strength bolts to a vertical bracket attached to the reinforcing column, as described in claim 1.

3. In the case where PC panels are attached to the outer surfaces of existing columns and beams in an apartment building, the additional slab, which is at approximately the same level as the orthogonal beam at the partition between units, is integrated with the existing structural surface via an indirect joint that includes the head of a thick-walled steel pipe shackle having legs that penetrate the PC panel and are embedded and fixed in the existing beam, as described in claim 1.

4. The additional reinforcing frame frame mounting structure according to claim 1, characterized in that the brace that can be attached to the additional reinforcing frame is a cross brace mechanism of two half-width flat steel plates fitted into the space surrounded by the reinforcing column and the reinforcing beam.

5. A method for constructing a structural surface structure to which an additional reinforcing frame structure is attached, characterized in that a bottom plate formwork is placed on the surface that is at the bottom of the surrounding space, and an additional slab is formed by injecting high-flow, non-shrinkage, high-strength mortar or high-flow, non-shrinkage, high-strength concrete into the surrounding space through injection holes that penetrate the floor slab vertically until it flows out through air vent holes that penetrate the floor slab.

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