JP2018059281A - Method for earthquake-resistant design of building and program for earthquake-resistant design - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earthquake-resistant design method capable of designing a building with good workability by suppressing material cost and reducing the burden of construction control, in the building having an intersection of a horizontal member such as a floor slab and a vertical member such as a wall.SOLUTION: An intersection (13) is composed of members constituting a floor slab (11), and a wall (12) is made of concrete having strength higher than that of the floor slab. An equivalent compressive strength (σ') calculated by considering the restraining effect of the floor slab is used for a material strength (σ) of the floor slab as the compressive strength of the intersection. If the equivalent compressive strength (σ') is equal to or greater than a compressive strength (σ) of the wall, the earthquake-resistant design is carried out by setting the compressive strength of an entire earthquake-resistant wall (21) obtained by combining the wall and the intersection to the compressive strength of the wall (σ).SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to a seismic design method for a building and a program for seismic design. In particular, the present invention relates to a method and program for performing seismic design after evaluating the strength of the intersection between a vertical member and a horizontal member.

  In a concrete building, there are parts such as beams and floor slabs and walls or pillars and floor slabs that are adjacent to each other but have different strengths required for concrete.

  In the case of beams and floor slabs, the effective width is set for floor slabs that extend from the top of the beam to the side in consideration of the influence of the floor slab on the beam. A design method is generally used in which the bending moment is calculated on the assumption that the floor slab of the effective width portion is integrated with the T-shaped beam. Further, for example, Patent Document 1 proposes a method for calculating the shear force by regarding the beam as a T-shaped beam.

JP 2006-97320 A

  However, there is no design method that considers the influence of both members, such as beams and floor slabs, at the intersections between vertical members such as walls and columns and horizontal members such as floor slabs and beams. When concrete of different strength is present, it is common to calculate the member strength with the lower concrete strength as a measure for ensuring safety.

  For example, as shown in FIG. 9, the intersection 4 between the floor slab 1 and the walls 2 and 3 is formed so that the floor slab 1 passes between the lower floor wall 2 and the upper floor wall 3. In this case, if the concrete strength of the lower floor wall 2 is A, the concrete strength of the floor slab 1 is B, and the concrete strength of the upper floor wall 3 is C, usually the concrete strength required for the floor itself is necessary for the wall. B <A = C because it is lower than the concrete strength. Moreover, since the Young's modulus is generally higher as the concrete strength is higher, the floor slab 1 is distorted larger than the walls 2 and 3 as indicated by the broken lines in the figure. In the design of the seismic wall including the upper and lower floor walls 2 and 3 and the intersection 4, if both ends of the floor slab 1 are free ends and there is nothing to restrain the distortion of the floor slab, The intersection 4 is destroyed before the walls 2 and 3 on the lower floor.

  If the same high-strength concrete as the walls and pillars is used for the floor slab in order to prevent the intersection from being destroyed first, the material cost increases and the burden of construction management for preventing shrinkage cracks increases.

  In order to use the same high-strength concrete as the walls and pillars at the intersections and low-strength concrete at the floors to prevent breakage at the intersections, a concrete mold around the walls and pillars. It is necessary to install a frame and separate the concrete, so the workability is poor.

  In view of the above problems, the present invention provides a seismic design method capable of designing a building having good workability by suppressing the material cost in a building having an intersection of a horizontal member and a vertical member and reducing the burden of construction management. The purpose is to provide a program for the seismic design.

An earthquake-resistant design method for a building (10) according to at least some embodiments of the present invention includes a concrete horizontal member (11) extending in a predetermined horizontal direction and a vertical direction perpendicular to the predetermined horizontal direction. A seismic design method for a building comprising a pair of upper and lower concrete vertical members (12) extending in a direction, coupled to the upper and lower surfaces of the horizontal member, and having a higher compressive strength than the horizontal member. A step of setting a compressive strength (σ _B1 ) of the vertical member, a step of setting a compressive strength (σ _B ) of the horizontal member, and an intersection (between the vertical members in the horizontal member) 13) The virtual restraining spring (15) has a function of preventing the crossing portion from receiving a vertical compressive force generated by an earthquake and spreading in the predetermined horizontal direction by the portion of the horizontal member adjacent to 13). A step of changing comes, the steps above using the spring constant of the restraining spring (k), to calculate the lateral pressure (sigma _r) acting in the predetermined horizontal direction relative to the intersecting portion when subjected to seismic force, by correcting the compressive strength of the horizontal member (sigma _B) taking into account the constraint effect by the lateral pressure, a step of calculating the equivalent compressive strength of the cross-section (σ _B '), the equivalent compressive strength (sigma _B When ') is equal to or higher than the compressive strength (σ _B1 ) of the vertical member, the compressive strength of the intersecting portion is set to the value of the compressive strength (σ _B1 ) of the vertical member, and the equivalent compressive strength (σ _B ') If less than the compressive strength of the vertical member (sigma _B1), the compressive strength of the horizontal member (sigma _B) an increase, the equivalent compressive strength (sigma _B') is the compressive strength of the vertical member ( σ _B1 ) It is characterized by comprising a top. When the equivalent compressive strength (σ _B ′) is smaller than the compressive strength (σ _B1 ) of the vertical member, the compressive strength of the vertical member is set to the value of the equivalent compressive strength (σ _B ′). May be. Here, the “horizontal member” means a member extending in the horizontal direction such as a floor slab or a beam, and the “vertical member” means a member extending in the vertical direction such as a wall or a column. .

  According to this configuration, since the seismic design can be performed without underestimating the strength of the intersection, the material cost can be suppressed and shrinkage cracking can be suppressed compared to the case where the same high-strength concrete as the vertical member is used for the horizontal member. The burden of construction management to prevent it can be reduced. Compared to the case of using the same high-strength concrete as the vertical member at the intersection and using low-strength concrete for the horizontal members other than the intersection, the workability is better because it is not necessary to install a stop formwork. It is.

  The building earthquake-resistant design method according to at least some embodiments of the present invention is the above-described configuration, wherein a plurality of sets of the vertical members are arranged in the predetermined horizontal direction, and the restraining springs are arranged in the predetermined horizontal direction. The spring constant of the constraining spring is determined by representing the elasticity of the part of the horizontal member corresponding to the part from the center line between the vertical members adjacent to each other to the intersection. . In particular, when the vertical member forms a wall and the horizontal member forms a floor slab, the restraining spring has a predetermined range of a bending compression region due to seismic force at the intersecting portion and It can be set to represent the elasticity of an isosceles trapezoidal portion having a center line as a base and an angle between a direction from the wall toward the center line and the leg is 0 ° or more and 45 ° or less.

  According to this configuration, the spring constant of the restraining spring can be easily obtained.

In the building seismic design method according to at least some embodiments of the present invention, in the above configuration, a correspondence relationship between the compressive strength (σ _B ) of the horizontal member and the equivalent compressive strength (σ _B ′) is obtained. A step of creating a table or graph, and in the step of setting the compressive strength (σ _B ) of the horizontal member, based on the table or graph, the equivalent compressive strength (σ _B ′) The compressive strength (σ _B ) of the horizontal member is set so as to be _{equal to} or higher than the strength (σ _B1 ).

  According to this configuration, it is possible to easily grasp the compressive strength required for the horizontal member, and it is possible to suppress re-design calculations.

A program for making an earthquake-resistant design of a building (10) according to at least some embodiments of the present invention includes a concrete horizontal member (11) extending in a predetermined horizontal direction, and the predetermined horizontal direction. For a seismic design of a building including a pair of upper and lower concrete vertical members (12) that are orthogonal to the horizontal member and are coupled to the upper and lower surfaces of the horizontal member in a crossing direction and having higher strength than the horizontal member. A program (ST1) for receiving an input of the compressive strength (σ _B1 ) of the vertical member, a means (ST3) for receiving an input of the compressive strength (σ _B ) of the horizontal member, and the horizontal member A virtual restraining spring having a function of preventing the crossing portion from receiving the seismic force and spreading in the predetermined horizontal direction by the horizontal member adjacent to the crossing portion located between the vertical members. And means (ST4) to replace the 15), wherein with the spring constant of the restraining spring (k), the lateral pressure (sigma _r) acting in the predetermined horizontal direction relative to the intersecting portion when subjected to seismic force Means for calculating (ST5) and means for calculating the equivalent compressive strength (σ _B ′) of the intersecting portion by correcting the compressive strength (σ _B ) of the horizontal member in consideration of the restraining effect due to the lateral pressure ( ST6) and when the equivalent compressive strength (σ _B ′) is equal to or greater than the compressive strength (σ _B1 ) of the vertical member, the compressive strength of the intersection is set to the value of the compressive strength (σ _B1 ) of the vertical member. The computer is caused to function as means (ST8). Furthermore, the program, the equivalent compressive strength (σ _B ') may the smaller than the compression strength of the vertical member (sigma _B1), the equivalent compressive strength (σ _B') is the compressive strength of the vertical member (sigma _B1) Means for re-inputting the compressive strength (σ _B ) of the horizontal member or setting the compressive strength of the vertical member to the value of the equivalent compressive strength (σ _B ′) The computer may function as (ST9).

  According to this configuration, since the seismic design can be performed without underestimating the strength of the intersection, the material cost can be reduced compared to the case where the same high-strength concrete as the vertical member is used for the horizontal member, and the construction management The burden can be reduced. Compared to the case of using the same high-strength concrete as the vertical member at the intersection and using low-strength concrete for the horizontal members other than the intersection, the workability is better because it is not necessary to install a stop formwork. It is.

Moreover, the building (10) having an earthquake-resistant design structure according to at least some embodiments of the present invention is configured to be orthogonal to the predetermined horizontal direction with a concrete horizontal member (11) extending in a predetermined horizontal direction. A building having a seismic design structure, comprising a pair of upper and lower vertical members (12) made of concrete and extending in the vertical direction, coupled to the upper and lower surfaces of the horizontal member and having higher compressive strength than the horizontal member The intersecting portion (13) located between the vertical members in the horizontal member is subjected to a restraining effect by the portion of the horizontal member adjacent to the intersecting portion in the predetermined horizontal direction, the compressive strength of the vertical member (sigma _B1), the greater than the compression strength of the horizontal member (sigma _B), compressive strength in consideration of the influence of in the restraining effect during an earthquake the horizontal member (sigma _B) Calculated with correction Was the equivalent compressive strength of intersection (σ _B '), characterized in that said greater than the compression strength of the vertical member (sigma _B1).

  According to this structure, since the building has predetermined earthquake resistance and the strength of the intersection is not underestimated, it is not necessary to use the same high-strength concrete as the vertical member at the intersection. Therefore, the material cost can be suppressed, the burden of construction management for preventing shrinkage cracks can be reduced, and the workability is good because there is no need to install a stop mold.

  According to the present invention, since the seismic design can be performed without underestimating the strength of the intersection, compared with the case where the same high-strength concrete as the vertical member is used for the horizontal member, the material cost can be suppressed, and the construction management can be performed. The burden can be reduced. Compared to the case of using the same high-strength concrete as the vertical member at the intersection and using low-strength concrete for the horizontal members other than the intersection, the workability is better because it is not necessary to install a stop formwork. It is.

Schematic longitudinal sectional view of a building according to an embodiment Schematic partial sectional plan view of a building according to an embodiment The figure which shows typically the structure equivalent to the wall and floor slab which concerns on embodiment. The longitudinal cross-sectional view which shows the intensity | strength of the material of the wall and floor slab which concerns on embodiment Flow chart of design method according to embodiment In the wall and floor slab according to the embodiment, a model diagram in which the influence of the floor slab on the intersection is replaced with an equivalent restraint spring. The partial cross section top view which shows the part set as a restraint spring among the elastic parts of the floor slab which concerns on embodiment The graph which shows the relationship between the concrete strength of the floor slab which concerns on embodiment, and the concrete strength at the time of side pressure consideration Longitudinal sectional view for explaining a conventional wall and floor slab design method

  Hereinafter, a design method of the building 10 according to the embodiment will be described with reference to the drawings. As shown in FIG. 1, a building 10 includes a reinforced concrete floor slab 11 extending in a horizontal direction, a vertical extension, coupled to the upper and lower surfaces of the floor slab 11, and a higher compressive strength than the floor slab 11. And a reinforced concrete wall 12 made of concrete having the following. The lower floor wall 12 and the upper floor wall 12 are arranged at positions aligned in the vertical direction. The building 10 is preferably provided with a plurality of walls 12 orthogonal to the longitudinal direction of the building, such as a plate-shaped apartment house. The inertial force (earthquake force) generated in the building 10 due to the earthquake acts like a horizontal force in a state where the building 10 is fixed to the ground as shown by an arrow in FIG. The building 10 is considered to have a mass concentrated on the floor level, and the horizontal force parallel to the wall 12 is designed to act on the floor level of each floor. Due to this seismic force, a compressive bundle concentrated in the lower right part of the building 10 in FIG. 1 is formed, so that force is also generated in the vertical direction, and at the intersection 13 (see FIG. 3) between the floor slab 11 and the wall 12 A region receiving a compressive force in the vertical direction and a region receiving a tensile force are generated.

  FIG. 2 is a cross-sectional view of an intermediate portion on a certain floor of the building 10, and both ends of the wall 12 are joined to the columns 14. Thick arrows in the figure indicate seismic force. A tensile force acts in the vertical direction (Z direction) on the side of the wall 12 that receives the seismic force, and a compressive force acts in the vertical direction on the opposite side. In the region where the compressive force acts, the intersection 13 (see FIG. 3) between the floor slab 11 and the wall 12 is compressed in the vertical direction, and therefore, as shown by the thin arrows in FIG. An attempt is made to spread in the orthogonal horizontal direction (X direction). However, since the distance between the walls 12 adjacent to each other in the X direction does not change even during an earthquake, deformation of the intersection 13 is suppressed by the portion adjacent to the intersection 13 of the floor slab 11.

  Such an action of force during an earthquake can be said to be equivalent to the structure shown in FIG. 3 in which the deformation in the X direction is constrained by the center line between the walls 12 adjacent to each other in the X direction. In the present embodiment, the concrete strength of the intersection 13 is calculated in consideration of the restraining effect on the intersection 13 by the floor slab 11, and the seismic design is performed.

As shown in FIG. 4, the concrete compression strength of the floor slab 11 is σ _B , and the compression strength of the wall 12 is σ _B1, and the design procedure will be described with reference to the flowchart of FIG.

First, basic data such as the concrete compressive strength σ _{B1 of} the wall 12 and the shape of the floor and the wall 12 are input (ST (step) 1).

Next, the presence or absence of the floor slab 11 is confirmed (ST2). When there is no floor slab 11, the design method according to the present embodiment is not applied. If there is a floor slab 11, the concrete compressive strength σ _B of the floor slab 11 is input (ST3).

  Next, the restraint state of the intersection 13 shown in FIG. 3 is replaced with a virtual restraint spring 15 shown in FIG. 6, and the spring constant k of the restraint spring 15 is calculated (ST4). In FIG. 6, the thick arrow indicates the vertical compressive force generated by the seismic force, and the broken line schematically indicates the shape of the intersecting portion 13 deformed by the compressive force. If the displacement of the intersecting portion 13 in the Z direction is Δz and the displacement extending to one side in the X direction is ½Δx, the restraining spring 15 suppresses the magnitude of Δx. For example, the restraining spring 15 can be set to represent the elasticity of an isosceles trapezoidal region in the floor slab 11 shown by a thin dot pattern in FIG. 7A, 7B, and 7C, the wall 12 is not joined to the pillar 14, the pillar 14 is joined to both ends of the wall 12, and the pillar 14 is attached to both ends of the wall 12, respectively. Are shown, and the beam 16 extends from the column 14 in a direction perpendicular to the wall 12. In any form, the spring constant k of the restraining spring 15 is calculated by the same calculation method. be able to. Although the wall 12 and the pillar 14 shown in FIG. 7 are cross sections, hatching for showing the cross section is omitted.

One base of the trapezoid is a boundary portion with the intersection 13 and receives a compressive force in the X direction from the intersection 13. The other base of the trapezoid is a middle line between the adjacent walls 12 and is a support portion 17 that supports the elastic portion. In the wall 12 and the intersecting portion 13, a shear fracture determination region 18 indicated by a dark dot pattern in FIG. 7 is set in the bending compression region, and the length in the horizontal direction (Y direction) along the wall 12 is l. _sc . The position of the base on the trapezoidal intersection 13 side corresponds to a portion adjacent to the shear fracture determination region 18 in plan view. The shear fracture determination region 18 is 1/3 of the length of the wall 12 in the Y direction from the end opposite to the side receiving the seismic force toward the side receiving the seismic force in the wall 12 and the intersection 13. It is a region up to about ½. The angle θ formed by the X direction (the direction from the wall 12 toward the support portion 17 and the trapezoidal height) and the trapezoidal leg is 0 ° or more and 45 ° or less, and the length l _B of the base on the support portion 17 side. Is not less than the length l _sc of the bottom side on the intersection 13 side. In addition, in the wall 12 provided on the end side of the building 10, regarding the restraining spring 15 on the side where the other wall 12 is not provided, a beam 19 (see FIG. 2) provided on the slab end, In order to constrain the deformation of the floor slab 11, bending reinforcement bars 20 (see FIG. 2) extending in the horizontal direction (Y direction) parallel to the wall 12 are installed, and these are represented by the floor slab 11 represented by the restraining spring 15. It is good also as the support part 17 of a trapezoidal elastic part.

ｋ：ばね定数
ω：設計上の安全率（１．０以下）
ｔ_ｓ：床スラブ１１の厚さ
ｌ_Ｂ：支持部１７側の底辺の長さ
ｌ_ｓｃ：壁１２及び交差部１３の曲げ圧縮領域に於けるせん断破壊判定領域の長さ（交差部１３側の底辺の長さ）
ｈ_ｓ：壁１２から支持部１７までの距離（台形の高さ）
Ｅ_ｃ：床スラブ１１のヤング係数 The spring constant k of the restraining spring 15 is calculated based on the deflection when a compressive force acts on the trapezoidal plate in the X direction. First, the deflection of a minute section in the X direction (the height direction of the trapezoid) is obtained, and this is integrated in the X direction to obtain the entire deflection. Here, the compressive force in the X direction is calculated on the assumption that the entire target region is applied uniformly. Next, the spring constant k is calculated by dividing the compression force by the total deflection. The spring constant k based on the above calculation is expressed by the following equation. When the specifications of the left and right of the wall 12 (slab thickness t _s , span h _s , Young's modulus E _c, etc.) are different, the respective spring constants k are calculated and average values are used.

k: Spring constant ω: Design safety factor (1.0 or less)
t _s : thickness of the floor slab 11 l _B : length of the bottom side on the support portion 17 side l _sc : length of the shear fracture determination region in the bending compression region of the wall 12 and the intersection portion 13 (on the intersection portion 13 side) Base length)
h _s : distance from the wall 12 to the support portion 17 (the height of the trapezoid)
E _c : Young's modulus of floor slab 11

Δｘ：Ｘ方向に拡がる変位
ν：コンクリートのポアソン比
ε_ｚ：圧縮ひずみ（交差部１３のＺ方向の変位（Δｚ）／床スラブ１１の厚さ（ｔ_ｓ））
ｔ_ｗ：壁１２の厚さ Next, as shown in FIG. 5, the side pressure σ _r acting on the intersection 13 from the restraining spring 15 is calculated (ST5). First, a displacement Δx extending in the X direction of the intersecting portion 13 is obtained. The displacement Δx is expressed by the following equation.

[Delta] x: displacement extends in the X direction [nu: Poisson's ratio of the concrete epsilon _z: Compression strain (Z-direction displacement of the intersection 13 (Δz) / thickness of the floor slab 11 _(t s))
t _w : thickness of the wall 12

σ_ｒ：側圧
α_ｓ：床スラブ１１の状況による係数。壁１２がｘ方向の両側から拘束される場合（壁１２に対してｘ方向の両側に床スラブ１１等がある場合）α_ｓ＝２、片側からのみ拘束される場合（壁１２に対してｘ方向の片側にのみ床スラブ１１等がある場合）α_ｓ＝１。 Next, the side pressure σ _r is obtained from Δx and the spring constant k. The side pressure σ _r is expressed by the following equation.

σ _r : lateral pressure α _s : coefficient depending on the situation of the floor slab 11. When the wall 12 is constrained from both sides in the x direction (when there is a floor slab 11 or the like on both sides in the x direction with respect to the wall 12) α _s = 2, when constrained only from one side (x with respect to the wall 12) When there is a floor slab 11 etc. only on one side in the direction) α _s = 1.

σ_Ｂ'：等価圧縮強度
σ_Ｂ：床スラブ１１のコンクリート圧縮強度（交差部１３の材料強度） Next, the equivalent compressive strength σ _B ′ of the intersection 13 is calculated (ST6). The intersection 13 has a strength higher than the material strength (concrete compressive strength σ _B of the floor slab 11) due to the restraining effect by the side pressure σ _r from the floor slab 11. The equivalent compressive strength σ _B ′ is a strength obtained by correcting the material strength in consideration of this constraint effect. It is known that the compressive strength of constrained concrete is high, and various calculation methods have been proposed. The equivalent compressive strength σ _B ′ can be calculated by any one of those calculation methods. For example, it can be calculated by the following formula.

σ _B ': Equivalent compressive strength σ _B : Concrete compressive strength of floor slab 11 (material strength of intersection 13)

Next, the magnitudes of the equivalent compressive strength σ _B ′ and the concrete compressive strength σ _B1 of the wall 12 are compared (ST7).

When the equivalent compressive strength σ _B ′ is equal to or greater than the concrete compressive strength σ _B1 of the wall 12, when the seismic force is applied, the wall 12 (base material) breaks before the intersection 13. Therefore, the design is performed by setting the compressive strength of the intersection 13 in the calculation of the seismic design to the value of the compressive strength of the wall 12 (ST8). That is, when it is considered that the seismic wall 21 is formed from the wall 12 and the intersecting portion 13 by design, the compressive strength of the entire seismic wall 21 is equal to the equivalent compressive strength σ _B ′ of the intersecting portion 13 and the concrete of the wall 12. among the compressive strength sigma _B1, designed regarded as concrete compressive strength sigma _B1 wall 12 is a compression strength of the smaller.

When it is determined that the equivalent compressive strength σ _B ′ is smaller than the concrete compressive strength σ _B1 of the wall 12, when the seismic force is applied, the crossing portion 13 breaks before the wall 12 (base material). It is determined whether or not to design with such an intersection destruction type (ST9). When designing with the intersection fracture type, design is performed by setting the compressive strength of the wall 12 in the calculation of the seismic design to the value of the equivalent compressive strength σ _B ′ (ST10). That is, the compressive strength of the entire earthquake-resistant wall 21 composed of the wall 12 and the intersecting portion 13 is the smaller compressive strength of the equivalent compressive strength σ _B ′ of the intersecting portion 13 and the concrete compressive strength σ _B1 of the wall 12. It is designed considering the equivalent compressive strength σ _B ′ of the intersection 13. When not designing with the intersection fracture type, the value of the concrete compressive strength σ _B of the floor slab 11 is increased and the process is repeated from ST3.

In addition, with respect to the floor slab 11 and the wall 12 of the typified shape, a graph showing a correspondence relationship between the concrete compressive strength σ _B and the equivalent compressive strength σ _B ′ of the floor slab 11 as shown in FIG. A table is prepared in advance, and in ST3, a value estimated that the equivalent compressive strength σ _B ′ is equal to or greater than the concrete compressive strength σ _B1 of the wall 12 is set as the concrete compressive strength σ _B of the floor slab 11. Also good.

A wall plate (horizontal bar D6 @ 85 mm, vertical bar D6 @ 50 mm) having a length of 1200 mm and a height of 900 mm, in which the lower end side is joined to the foundation beam and the upper end side is joined to the force beam, is used as an example of the present invention. Tests were conducted for the comparative example. In Comparative Example 1, the entire wall plate was cast with the same concrete. In Comparative Example 2, a low-strength layer having a height of 50 mm was provided on the leg portion of the wall plate, but the thickness was the same as that of the wall plate body, and no portion corresponding to the floor slab was provided. In Examples 1 to 4, a low-strength layer having a height of 50 mm is provided on the leg portion of the wall plate, and the low-strength layer is a slab having a length of 300 mm in a direction orthogonal to the wall plate, on both sides of the wall plate. It corresponded to the state with a floor slab. The slabs of Examples 1 to 4 are provided with slab bars (D6 @ 100 mm) for fixing the slab to the foundation beam. Furthermore, the slabs of Examples 2 to 4 have a U extending in a direction perpendicular to the wall plate. Character restraint was provided. The U-shaped constraining bars of Example 2 were not fixed to the foundation beam, and the U-shaped constraining bars of Examples 3 and 4 were fixed to the foundation beam by bending both ends downward. Table 1 shows the properties of the test specimens.

Based on Equations 1 to 4, the equivalent compressive strength σ _B ′ of Examples 1 to 4 was calculated. In calculating the equivalent compressive strength σ _B ′, the design safety factor ω is 1.0, l _sc is 400 mm, which is 1/3 of the length of the wall plate, and the height of the trapezoidal portion of the slab represented by the restraining spring The angle θ between the direction and the leg (see FIG. 7) was 45 °, the Poisson's ratio ν was 0.4 (considering the plastic region), and the compressive strain ε _z was 2000 micro. In all the test bodies of Examples 1 to 4, the equivalent compressive strength σ _B ′ was larger than the compressive strength σ _B1 of the wall plate body. In addition, the strength based on the material strength of the wall body and the strength based on the material strength of the low strength layer were calculated.

A horizontal force parallel to the wall plate corresponding to the seismic force was applied to the specimen. The horizontal force was applied repeatedly with positive and negative displacements. The experimental results and calculation results are shown in Table 2.

In Examples 1 to 4, since the equivalent compressive strength σ _B ′ was greater than the compressive strength σ _{B1 of} the wall plate main body, according to the present invention, the entire wall plate combining the wall plate main body and the low strength layer. Can be regarded as the compressive strength σ _B1 of the wall body (ST8 in FIG. 5). For Examples 1 to 4, when the maximum load of the experimental value and the strength of the wall plate main body were compared, the maximum load of the experimental value was larger, indicating the safety of the seismic design method according to the embodiment.

  In addition, since Comparative Examples 1 and 2 were broken at a value smaller than the bending strength, the fracture type was judged to be shear fracture, but Examples 1 to 4 were broken at a value larger than the bending strength, so the fracture type was Judgment of bending failure.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. Instead of the intersection between the wall and the floor slab, the present invention may be applied to the intersection between the column and the floor slab, the intersection between the wall and the beam, or the intersection between the column and the beam. The shape of the elastic portion of the floor slab represented by the restraining spring may be changed. Further, the present invention may be applied to a program for causing a computer to function as means corresponding to each step of the above embodiment.

10: Building 11: Floor slab (horizontal member)
12: Wall (vertical member)
13: Crossing part 14: Column 15: Restraining spring 16: Beam 17 extending in the X direction 17: Supporting part 18: Shear fracture judgment area 19: Beam extending in the Y direction 20: Bending reinforcement 21: Seismic wall

Claims (7)

A concrete horizontal member extending in a predetermined horizontal direction, and a vertical member extending in a vertical direction orthogonal to the predetermined horizontal direction, coupled to the upper and lower surfaces of the horizontal member, and higher in compression than the horizontal member. A seismic design method for a building having strength and a pair of concrete upper and lower vertical members,
Setting the compressive strength (σ _B1 ) of the vertical member;
Setting the compressive strength (σ _B ) of the horizontal member;
In the horizontal member, the intersection of the horizontal member adjacent to the intersection located between the vertical members is prevented from spreading in the predetermined horizontal direction due to the vertical compressive force generated by the earthquake. Replacing the function to be replaced with a virtual restraint spring;
Using the spring constant of the restraining spring to calculate a lateral pressure acting in the predetermined horizontal direction on the intersecting portion when subjected to seismic force;
Calculating the equivalent compressive strength (σ _B ′) of the intersecting portion by correcting the compressive strength (σ _B ) of the horizontal member in consideration of the restraining effect due to the lateral pressure;
When the equivalent compressive strength (σ _B ′) is equal to or higher than the compressive strength (σ _B1 ) of the vertical member, the compressive strength of the intersection is set to the value of the compressive strength (σ _B1 ) of the vertical member, When the equivalent compressive strength (σ _B ′) is smaller than the compressive strength (σ _B1 ) of the vertical member, the equivalent compressive strength (σ _B ′) is increased by increasing the compressive strength (σ _B ) of the horizontal member. An earthquake-resistant design method for a building, comprising the step of setting and designing so as to be _{equal to} or higher than the compressive strength (σ _B1 ) of the vertical member. A concrete horizontal member extending in a predetermined horizontal direction, and a vertical member extending in a vertical direction orthogonal to the predetermined horizontal direction, coupled to the upper and lower surfaces of the horizontal member, and higher in compression than the horizontal member. A seismic design method for a building having strength and a pair of concrete upper and lower vertical members,
Setting the compressive strength (σ _B1 ) of the vertical member;
Setting the compressive strength (σ _B ) of the horizontal member;
In the horizontal member, the intersection of the horizontal member adjacent to the intersection located between the vertical members is prevented from spreading in the predetermined horizontal direction due to the vertical compressive force generated by the earthquake. Replacing the function to be replaced with a virtual restraint spring;
Using the spring constant of the restraining spring to calculate a lateral pressure acting in the predetermined horizontal direction on the intersecting portion when subjected to seismic force;
Calculating the equivalent compressive strength (σ _B ′) of the intersecting portion by correcting the compressive strength (σ _B ) of the horizontal member in consideration of the restraining effect due to the lateral pressure;
When the equivalent compressive strength (σ _B ′) is equal to or higher than the compressive strength (σ _B1 ) of the vertical member, the compressive strength of the intersection is set to the value of the compressive strength (σ _B1 ) of the vertical member, When the equivalent compressive strength (σ _B ′) is smaller than the compressive strength (σ _B1 ) of the vertical member, the compressive strength of the vertical member is set to the value of the equivalent compressive strength (σ _B ′). A seismic design method for a building, comprising: A plurality of the vertical members are arranged in the predetermined horizontal direction,
The restraining spring is set to represent elasticity of a portion of the horizontal member corresponding to a portion extending from a center line between the vertical members adjacent to each other in the predetermined horizontal direction to the intersecting portion; The seismic design method according to claim 1, wherein the spring constant is obtained. The vertical member forms a wall;
The horizontal member forms a floor slab;
In the plan view, the restraint spring has a predetermined range of a bending compression region due to seismic force at the intersection and the center line as a base, and an angle formed between the direction from the wall toward the center line and the leg. The seismic design method according to claim 3, wherein the seismic design method is set to represent elasticity of an isosceles trapezoidal part that is 0 ° to 45 °. Further comprising the step of creating a table or graph showing the correspondence between the compressive strength (σ _B ) of the horizontal member and the equivalent compressive strength (σ _B ′),
Wherein in the step of setting the compressive strength of the horizontal member (sigma _B), based on the table or chart, the equivalent compressive strength (σ _B ') is the horizontal such that the compressive strength of the vertical member (sigma _B1) or The earthquake-resistant design method according to any one of claims 1 to 4, wherein the compressive strength (σ _B ) of the member is set. A concrete horizontal member extending in a predetermined horizontal direction, and a concrete horizontal member orthogonal to the predetermined horizontal direction, coupled to the upper and lower surfaces of the horizontal member in a crossing direction and having higher strength than the horizontal member. A program for seismic design of a building comprising a pair of upper and lower vertical members,
Means for receiving an input of the compressive strength (σ _B1 ) of the vertical member;
Means for receiving an input of the compressive strength (σ _B ) of the horizontal member;
An imaginary restraint function of the horizontal member adjacent to the intersection located between the vertical members in the horizontal member to suppress the intersection from spreading in the predetermined horizontal direction due to seismic force. Means to replace it with a spring;
Means for calculating a side pressure acting in the predetermined horizontal direction with respect to the intersection when receiving a seismic force using a spring constant of the restraining spring;
Means for calculating the equivalent compressive strength (σ _B ′) of the intersecting portion by correcting the compressive strength (σ _B ) of the horizontal member in consideration of the restraining effect due to the lateral pressure;
Wherein when the equivalent compressive strength (σ _B ') is compressive strength (sigma _B1) or of the vertical member, the computer as a means for setting the compressive strength of the intersection of the value of compressive strength (sigma _B1) of the vertical member A program to make it work. When the equivalent compressive strength (σ _B ′) is smaller than the compressive strength (σ _B1 ) of the vertical member, the equivalent compressive strength (σ _B ′) is equal to or higher than the compressive strength (σ _B1 ) of the vertical member. Re-input the compression strength (σ _B ) of the horizontal member, or cause the computer to function as a means for accepting selection of whether to set the compression strength of the vertical member to the value of the equivalent compression strength (σ _B ′) The program according to claim 6, further comprising:

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