JPS6117677A - Earthquake resistant wall made of reinforced concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention is a medium-to-high-rise building made of reinforced concrete (hereinafter referred to as RC construction), in which the beams do not bulge vertically in the center. Regarding the RC shear wall that is implemented as a possible seismic element of the frame part, more specifically, large-diameter reinforcing bars with both ends fixed to the upper and lower beams are arranged in the middle part of the wall plate, thereby strengthening the upper and lower beams. RC configured to restrain bulges (prior art and its problems, etc.) The mechanical performance of conventional general shear failure type shear walls, as shown by the curve ■ in Figure 1, has a high yield strength, but the maximum yield strength is There was little deformation over time, and after the maximum yield strength, the yield strength rapidly decreased, resulting in brittle fracture behavior and poor deformation performance.

The RC shear wall constructed in the Showa era consists of large-diameter reinforcing bars placed in the middle of the wall plate with both ends anchored to the upper and lower beams.The basic mechanism is: ■ Giving the large-diameter reinforcing bars the role of studs. .

■ Large-diameter reinforcing bars restrain free deformation of columns and beams (surrounding frames).

■ Large-diameter reinforcing bars restrain the rotation of the dividing wall plate.

It is based on such technological ideas.

Therefore, the mechanical performance of this RC shear wall, as shown by the curve @ in Figure 1, is excellent in deformation performance and there is no sudden drop in strength even after the maximum strength, so the performance has been significantly improved. It turns out.

However, the maximum yield strength indicated by θ in Figure 1 is developed before and after the formation of a so-called mechanism in which shear slip occurs at each easily sheared point, and then the yield strength decreases once until the large-diameter reinforcing bars act, and then becomes constant. The deformation increases due to the yield strength.

Therefore, it was difficult to calculate the yield strength, which made economical design difficult.

(Objective of the Invention, Technical Problem to be Solved) Therefore, the object of the present invention is to provide a structure that is rich in toughness with a deformable member angle R = 20/1000 Rad or more, and that allows for a clear understanding of mechanical performance and easy calculation of proof stress. The object of the present invention is to provide an improved RC shear wall with a structure that is easy to cast on-site.

(Configuration and effects of the first invention) In order to achieve the above object, the RC shear wall of the present invention is provided with pipes that form easy shear points in the vertical longitudinal direction of the middle part of the wall plate, and The structure is such that large-diameter reinforcing bars fixed to the upper and lower beams are passed through the pipe.

The pipe should be a synthetic resin pipe or a pipe made of paper, fiber, or tin that can withstand the pressure of concrete placement, and its outer diameter should be at least 40 inches thicker than the wall thickness in order to identify areas where shear is likely to occur. be done.

However, in the case of this RC shear wall, when horizontal shear force loads cause shear slip in easy-to-shear areas, dividing the wall plate into left and right pieces and causing the upper and lower beams to bulge outward, large-diameter reinforcing bars are immediately removed. It acts to restrain the bulge. Large diameter reinforcing bars act as tension members.

Therefore, its mechanical performance is shown by curve O in Figure 1, and after reaching the maximum yield strength, the deformation continues to increase to R = 20/1000 Rad or more as the large diameter reinforcing bars yield.
No reduction in yield strength occurs. In other words, mechanical performance can be clearly understood,
It is easy to calculate the yield strength as the yield strength of large diameter reinforcing bars.

In addition, since the pipes that form the easy shear points are installed vertically and vertically, they do not interfere with concrete pouring, making it easy to cast on site.

(Configuration and effects of the second invention) In order to achieve the same object, the RC shear wall of the present invention has the configuration of the first invention, that is, pipes are installed in the vertical direction of the middle part of the wall plate. The main structure consists of large-diameter reinforcing bars with both ends fixed to the upper and lower beams, passed through the nodules, and on top of that, easy-to-shear points are placed at the boundaries of the wall plates along the beams. It is said that the configuration is as follows.

The easy-to-shear points are provided by means such as concrete pouring, cross-sectional defects by embedding pipes, etc., or cutting of reinforcing bars.

However, the wall plates and pillars are designed to be integrated as much as possible.

Therefore, the mechanical deformation state of this RC shear wall is shown in a conceptual diagram in Figure 2.The wall plate 3 and the upper and lower beams 2
, 2' due to easy shear points, shear slip occurs with a certain resistance force and the edges are cut off.
' deforms as if expanding, and inevitably the large diameter reinforcing bars 4 work effectively as tension members from the beginning.

The flow of force at this time is that the water drying shear force Q is first transmitted as a shear force Qw to the left partition wall plate 3, and this shear force Qw is the bending force QB of the upper and lower beams 2 and 2' 4
It is transmitted as a tensile force T. Expressing this as a formula, Q = Qw X cotθ” (T+ 2 Qn)
The yield strength can be calculated clearly as X cot θ. If this is shown in a load deformation diagram, it will be as shown by curve O in Fig. 1.

That is, the smaller the shear angle θ is, the more effective it is.

Therefore, depending on the horizontal length of the wall plate 3, it is preferable to arrange the large-diameter reinforcing bars at two or more locations as shown in FIG. 3, depending on the case, so that θ does not become too large.

By the way, all of the inventions of the present application are based on the premise that the beams 2, 2' deform as if swollen when subjected to a water-drying shear force, as described above. For this reason, the locations where the RC shear walls are applied to buildings should be selected and implemented in locations where there are no vertically connected layers, as shown with diagonal lines in Figure 4. However, this is only possible on the lowest floor if the foundation beam can be made smaller and there is a possibility of it expanding.

Considering such force conditions, the field of application of the RC shear wall of the present application is rather suitable for medium and high-rise buildings.

(Configuration and effects of the third invention) In order to achieve the above object, the RC shear wall of the present invention has the configuration of the first invention, that is, the middle part of the wall board can be easily sheared in the vertical longitudinal direction. The main structure consists of pipes that form the sections, and large-diameter reinforcing bars that are firmly fixed to the beams at both ends as vertical longitudinal reinforcing bars. However, the large-diameter reinforcing bars have almost no contact with the concrete. It is characterized by a structure in which it is made of unbonded steel material, and the steel is arranged near the pipe in a substantially symmetrical arrangement on both sides thereof.

Therefore, although there are some differences in structure, the effects achieved by this invention are almost the same as those of the first invention.

(Structure and effect of the fourth invention) In order to achieve the same object, the RC shear wall of the present invention has the structure of the first invention, that is, the middle part of the wall plate can be easily sheared in the vertical longitudinal direction. The main structure consists of pipes that form the sections, and large-diameter reinforcing bars that are firmly fixed to the beams at both ends as vertical longitudinal reinforcing bars. However, the large-diameter reinforcing bars have almost no contact with the concrete. It is made of unponded steel, and is reinforced in a substantially symmetrical arrangement on both sides close to the pipe, as well as easy shear points where the transmission of shear force is small at the boundary part of the wall plate along the beam. It is characterized by the following configuration.

Therefore, although there are some differences in structure, the effects achieved by this invention are almost the same as those achieved by the second invention.

(Example) .

The RC shear wall shown in Figures 5 and 6 has a Δ6
The structure is such that the hoop muscle 1b or 2b is wound and reinforced. In addition, 04 reinforcing bars are used for the vertical and horizontal reinforcements 3a and 3b of the wall board 1, and the structure is configured as a double reinforcement arrangement with an interval of 100 cm.

Note that the horizontal reinforcement 3b is inserted sufficiently deeply into the column reinforcing bars and fixed, but the vertical reinforcement 3a is cut in front of the upper and lower beams 2, 2'.

In other words, the wall plate 3 and the pillar 1.1' have an integrated structure, but the wall plate 3 and the beams 2, 2' have a structure that allows shear slippage.

4 in the figure is a large diameter reinforcing bar, which is passed through a pipe 10 installed to form an easy shearing point in the vertical longitudinal direction of the middle part of the wall board 3, and its upper and lower ends 4a and 4b are the upper and lower beams. It is inserted deeply into the reinforcing steel and firmly fixed.

Therefore, the large diameter reinforcing bars 4 and wall plate concrete are pipe 1.
Since the edges are completely cut off at zero, they can act independently against the shear force. In other words, the large-diameter reinforcing bars 4 act as a material that bears only tensile force.

19 reinforcing bars are used on the large diameter reinforcing bar 4.

Since its tensile yield is 3900 to 9/cd, the strength of the RC shear wall is approximately 30 tons, and the deformation capacity is 30/1.
It can be calculated as 000 Rad.

For the pipe 10, a material that is not too strong enough to withstand the pressure of poured concrete, such as a vinyl chloride pipe, a paper pipe, a fiber pipe, a tin plate pipe, etc., is used. The outer diameter of the pipe 10 is at least 40 inches or more (z60 to 080) relative to the wall thickness (usually 150 to 180 m) in order to identify locations where shear is easy. However, it is not limited to circular pipes.

In short, since the cavity created by the pipe 10 becomes a cross-sectional defect in the wall plate, a thin layer easily sheared area 9 is formed in the thinnest inner part of both outer sides of the pipe 100, and shear slip is induced there.

However, this easily sheared area 9 is characterized by an external design that is completely indistinguishable from a normal wall when it is not destroyed.

In the figure, 5 is a pipe installed in the wall board 3 in order to form an easy shearing area at the boundary part along the upper and lower beams 2 and 2'.

This RC shear wall is completed by assembling reinforcing bars, etc. with the above structure, and then pouring concrete on-site.

Therefore, in response to a load of water-dried shear force on the foot, the pipes 5 and 10 are first compressed and crushed, and shear slip is induced at the easy-to-shear points, forming a mechanism. That is, the deformation as shown in the conceptual diagram in FIG. 2 occurs, and the wall plate 3 is divided into two pieces, one on the left and one on the left, which is an integrated structure with the columns 1 and 1', and the deformation occurs as the large diameter reinforcing bars 4 yield. The elongation and yield strength calculated and the strength of the oshi are maintained even during deformation.

(Second Embodiment) Most of the configuration of the RC shear wall shown in FIGS. 7 and 8 is the same as in the first embodiment.

However, unbonded steel 4', which has almost no friction with concrete, is used in place of the large-diameter reinforcing bars, and this is installed in the vertical direction in the middle of the wall plate 3 on both outsides of the pipe 10. The two ends 4a' and 4b' are arranged closely and substantially symmetrically so that they are inserted sufficiently deeply into the reinforcing bars of the upper and lower beams 2 and 2' to be firmly fixed.

The unbonded steel material 4' has an asphalt-based substance applied to its surface and a shield applied thereon, and is a material that acts differently from concrete in response to horizontal shear force and bears only vertical tensile force. exist.

Therefore, even in the case of this RC shear wall, the deformation as shown in the conceptual diagram in Figure 2 due to the load of water-drying shear force,
Shear slip occurs, and as shown by curve O in FIG. 1, the deformation extends well to 20/1000 Rad or more at a predetermined proof stress, and no decrease in proof stress occurs during deformation. That is, unbonded steel material 4'
The yield strength can be calculated clearly.

(Third Embodiment) The RC shear wall shown in FIG. 9 uses large diameter reinforcing bars 4 (or unbonded steel 4') as vertical reinforcing bars in the vertical direction of the middle part of the wall plate 3. A steel plate 11 (with a width slightly narrower than the wall thickness) is arranged with both ends firmly fixed to the upper and lower beams 2, 2', and is placed in close proximity to the large-diameter reinforcing bars 4 to form easy shear points on both left and right sides thereof. or Teflon board, wood, or other materials). iron plate 1
The thin walled portions on the outside of both ends of the wall plate 10 are easily sheared, and shear slip is induced there, thereby dividing the wall plate 3 into two left and right pieces.

The rest of the configuration is as described in 1 above. There is no difference from that of the second embodiment.

Therefore, this RC shear wall also undergoes deformation and shear slip as shown in the conceptual diagram in Figure 2 under the load of water-drying shear force, and the deformation and elongation are good without reducing the bearing strength. The yield strength can be clearly calculated as the yield strength of the diameter reinforcing bar 4.

(Other Examples) Note that it is also possible to form the wall plate with a PC board. In this case, where it is necessary to integrate it with the surrounding frame, it is connected using a cotter or the like.

[Brief explanation of drawings]

Fig. 1 is a graph showing the load deformation relationship between the conventional example and the RC shear wall according to the present invention, Fig. 2 is a conceptual diagram showing the mechanical deformation state of the RC shear wall according to the present invention, and Fig. 3 4 is a conceptual diagram showing the pariage 1 of the RC shear wall according to the present invention, FIG. 4 is a conceptual diagram of a building showing an application example of the RC shear wall according to the present invention, and FIG. The reinforcing bar assembly diagram of the RC shear wall showing an example, Figure 6 is the same as ■ in Figure 5.
FIG. 7 is a sectional view taken along arrows -■, FIG. 7 is a reinforcing bar assembly diagram of the second embodiment, FIG. 8 is a sectional view taken along arrows -■ in FIG. 7, and FIG. 9 is a sectional view of the third embodiment. 2E 3WA 4th WA 58iQ Figure 6 Figure 7 811 Figure 9

Claims (4)

[Claims] (1) In a reinforced concrete shear wall in which a reinforced concrete wall plate is integrally installed within the frame surface surrounded by reinforced concrete columns and beams, shearing is easy in the vertical longitudinal direction of the middle part of the wall plate (3). part(
9) is installed, and large-diameter reinforcing bars (4) with both ends firmly fixed to the beams (2) and (2') as vertical longitudinal reinforcing bars are placed through the pipe (10). A reinforced concrete shear wall characterized by its striations. (2) In a reinforced concrete shear wall where a reinforced concrete wall plate is integrally installed within the frame surface surrounded by reinforced concrete columns and beams, shearing is easy in the vertical longitudinal direction of the middle part of the wall plate (3). part(
9) is installed, and large-diameter reinforcing bars (4) with both ends firmly fixed to the beams (2) and (2') as vertical longitudinal reinforcing bars are placed through the pipe (10). A shear wall made of reinforced concrete, characterized in that the wall plate (3) is provided with easily sheared areas (5) with a small shearing force transmission capacity along the beams (2) and (2'). . (3) In a reinforced concrete shear wall where a reinforced concrete wall plate is integrally provided within the frame surface surrounded by reinforced concrete columns and beams, shearing is easy in the vertical longitudinal direction of the middle part of the wall plate (3). part(
A pipe (10) forming a pipe (9) is installed, and an unbonded steel member (4') whose both ends are firmly fixed to the beams (2) and (2') as a vertical longitudinal reinforcing bar is brought close to the pipe (10) and attached to the pipe (10). A reinforced concrete shear wall characterized by having reinforcement arranged symmetrically on both sides. (4) In a reinforced concrete shear wall where a reinforced concrete wall plate is integrally installed within the frame surface surrounded by reinforced concrete columns and beams, shearing is easy in the vertical longitudinal direction at the middle part of the wall plate (3). part(
A pipe (10) forming a pipe (9) is installed, and an unbonded steel member (4') whose both ends are firmly fixed to the beams (2) and (2') as a vertical longitudinal reinforcing bar is brought close to the pipe (10) and attached to the pipe (10). Reinforcement is arranged in a symmetrical arrangement on both outer paths, and easy shear points (5) with low shear force transmission capacity are provided in the wall plate (3) along the beams (2) and (2'). A reinforced concrete shear wall with the following features: