Improved calculation method of equivalent stiffness ratio of partial frame-supported shear wall structure system

Abstract

The application discloses an improved calculation method of equivalent stiffness ratio of a partial frame-supported shear wall structure system, and the method comprises the following steps: a whole structure calculation model is split into a lower structure independent model under a transfer floor, an upper n-layer structure independent model above the transfer floor and an upper n+1-layer structure independent model above the transfer floor, and displacement and stiffness indexes corresponding to the three models are calculated; the lateral stiffness of the upper structure is calculated by using a linear interpolation method of the height of the lower structure under the transfer floor between the height of the upper n-layer structure above the transfer floor and the height of the upper n+1-layer structure above the transfer floor; and then, the improved equivalent stiffness ratio which eliminates the influence of the height value is calculated. The improved equivalent stiffness ratio calculated by the method can accurately reflect the relative stiffness relationship between the lower structure under the transfer floor and the upper structure, avoids the sudden change of the calculated value of the equivalent stiffness ratio in the limit height according to the current standard, and can better guide the design work of the partial frame-supported shear wall structure system.

Description

Technical Field

[0001] This invention belongs to the field of building engineering technology and relates to an improved calculation method for the equivalent stiffness ratio of a partially frame-supported shear wall structure system. Background Technology

[0002] Partially frame-supported shear wall structures are irregular structural systems characterized by abrupt changes in vertical stiffness and discontinuous lateral force resisting members. The shear walls' absence from the ground causes abrupt changes in the transmission path of horizontal seismic shear force; some of the seismic shear force from these shear walls must be transferred to other grounded shear walls through the horizontal members of the transfer layer. From the perspective of lateral force resisting member composition, the structure below the transfer layer is a frame-shear wall structural system composed of grounded shear walls and frame-supported frames. Due to the changes in the force transmission path and lateral force resisting system between the upper and lower structures of the transfer layer, rationally designing the stiffness of the transfer layer and the structure below it, thereby controlling the overall structural stiffness index, the degree of abrupt changes in internal forces within members, and the structural plastic yielding mechanism, is the core focus of partially frame-supported shear wall structure design.

[0003] For partially frame-supported shear wall structures where the transfer layer is located above the second floor, the equivalent stiffness ratio is the main indicator reflecting the stress characteristics of the partially frame-supported shear wall structure. The equivalent stiffness ratio is the ratio of the equivalent lateral stiffness of the lower structure and the upper structure of the transfer layer. The equivalent stiffness ratio is calculated as shown in Appendix E of the Technical Specification for Concrete Structures of High-Rise Buildings (JGJ 3-2010).

[0004] In the formula, △1 is the lateral displacement of the top of the lower structure of the transfer layer under a unit horizontal force, △2 is the lateral displacement of the top of the upper structure of the transfer layer under a unit horizontal force, H1 is the height of the lower structure of the transfer layer, H2 is the height of the upper structure of the transfer layer, H2 should be equal to or close to H1, and H2≤H1.

[0005] Because the height H2 of several floors in the superstructure must be less than or equal to H1, and the value of H2 is limited by the floor height of the superstructure. When the height H1 of the superstructure is within H... 2(n) and H 2(n+1) Between them, it is even very close to H. 2(n+1) At that time, according to the "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010, H2 should be taken as H 2(n) That is, the sum of the heights of the n layers above the conversion layer, but when H1 increases slightly, it equals H. 2(n+1) H2 can take the value H 2(n+1)This refers to the total height of the n+1 floors above the transfer floor. Therefore, the height of the structure above the transfer floor must be an integer multiple of the floor height. This determines that the stiffness values ​​of the structure above the transfer floor are all limit values, while the stiffness of the structure below the transfer floor gradually changes with its height H1 according to a basically certain functional relationship. This inevitably results in an equivalent stiffness ratio γ. e The calculated values ​​abruptly change at the limit height, failing to accurately reflect the relative stiffness between the lower and upper structures of the transfer layer. Summary of the Invention

[0006] The purpose of this invention is to provide an improved calculation method for the equivalent stiffness ratio of partially frame-supported shear wall structural systems, based on the current design code "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010. This method ensures that the improved equivalent stiffness ratio accurately reflects the relative stiffness relationship between the lower and upper structures of the transfer floor, avoiding the need for an equivalent stiffness ratio γ. e The calculated value abruptly changes at the limit height, which better guides the design of partially frame-supported shear wall structural systems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An improved calculation method for the equivalent stiffness ratio of partially frame-supported shear wall structures is proposed. This method improves the equivalent stiffness ratio by linear interpolation based on the height of the substructure, eliminating errors caused by differences in the calculated heights of the substructure and the superstructure. The method includes the following steps: S1: Based on BIM technology (such as Yingjianke Architectural Structure Design Software YJK, PKPM Structural Design Software, etc.), establish an overall calculation model of the building structure according to the architectural layout drawings and functional requirements; S2: Based on the overall structural calculation model, separate independent models are created for the lower part of the transfer floor, the upper n-story structure, and the upper n+1-story structure. The height of the lower part of the transfer floor independent model is H1, and the height of the upper n-story structure independent model is H. 2(n) The height of the independent model of the n+1 layers above the conversion layer is H. 2(n+1) And H 2(n) ≤H1≤H 2(n+1) ; S3: Apply the same unit horizontal force to the top of the independent models of the lower structure of the transfer layer, the independent models of the n upper layers of the transfer layer, and the independent models of the n+1 upper layers of the transfer layer, respectively, and collect the corresponding lateral displacements Δ1 and Δ2. 2(n) and △ 2(n+1) data; S4: Due to floor height restrictions, the height of the upper structure cannot be the same as that of the lower structure. The heights H1 and H2 should be determined according to the specifications in the "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010. 2(n)and H 2(n+1) The linear proportional relationship between them is expressed in 1 / Δ 2(n) and 1 / △ 2(n+1) The improved lateral displacement Δ of the superstructure is obtained by linear interpolation between the two values. * 2. The specific calculation formula is as follows: (1) S5: Calculate the improved equivalent stiffness ratio. The calculation formula is shown below: (2) S6: Verify the improved equivalent stiffness ratio γ * e Check whether the calculated value meets the limit requirements for the equivalent stiffness ratio of partially frame-supported shear walls in the "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010. If it does, proceed to the next step of structural design. If it does not, return to step S2, adjust the structural layout and reset the various indicators until the requirements of the specification are met.

[0008] Appendix E.0.3 of the Technical Specification for Concrete Structures of High-Rise Buildings (JGJ 3-2010) stipulates that γ * e It is advisable to be close to 1, and γ should be used in non-seismic design. * e γ should not be less than 0.5 during seismic design. * e It should not be less than 0.8.

[0009] Compared with the prior art, the beneficial effects of the present invention are: 1. This method ensures that the improved equivalent stiffness ratio can accurately reflect the relative stiffness relationship between the lower and upper structures of the transfer layer, eliminates the influence of the floor height limit on the height of the upper structure of the transfer layer, avoids abrupt changes in the calculated value of the equivalent stiffness ratio γe at the limit height, and better guides the design work of some frame-supported shear wall structural systems.

[0010] 2. The improved equivalent stiffness ratio calculated by this method can be obtained from the results output by existing structural design software (such as Yingjianke Architectural Structure Design Software YJK, PKPM Structural Design Software, etc.) through simple conversion, which is beneficial for designers to master. Attached Figure Description

[0011] Figure 1 This is a flowchart of the calculation method of the present invention.

[0012] Figure 2 This is a schematic diagram of the conversion layer and lower structure of computational model 1.

[0013] Figure 3This is a schematic diagram of the n-layer structure above the conversion layer in computational model 2.

[0014] Figure 4 This is a schematic diagram of the n+1 layer structure above the conversion layer in computational model 3.

[0015] Figure 5 This is a structural standard layer layout diagram provided in an embodiment of the present invention.

[0016] Figure 6 This is a structural conversion layer layout diagram provided in an embodiment of the present invention.

[0017] Figure 7 This is a comparison chart of the improved equivalent stiffness ratio provided in the embodiments of the present invention and the equivalent stiffness ratio of the current standard. Detailed Implementation

[0018] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. Example

[0019] A high-rise commercial and residential building is located in a seismic fortification zone with an intensity of 8 degrees (0.2g), a site characteristic period of 0.45s, and a site category of Class II. The bottom three floors are commercial, while floors four through thirty-two are residential, with a floor height of 2.9 meters for all residential floors. To maximize the usability of the commercial space, the shear wall on the south side of the residential units cannot be grounded and requires a frame-supported transfer structure. Therefore, this project adopts a partially frame-supported shear wall structure, with the transfer floor located on the third floor. The bottom two floors have a floor height of 4.5 meters, and the transfer floor has a floor height of 5.0 meters. The structural layout diagrams of the standard floors and transfer floors in this embodiment are shown below. Figure 5 and 6 .

[0020] Reference Figure 1 The improved calculation method for the equivalent stiffness ratio of some frame-supported shear wall structures in this embodiment is as follows: S1: Based on the architectural layout drawings and functional requirements, an overall structural calculation model of the building is established using existing BIM-based architectural structural design and calculation software (YJK architectural structural design software). S2: Based on the overall building structure calculation model, separate independent models of the lower structure of the transfer floor (height H1) and the upper four-story structure of the transfer floor (height H2) are created. 2(4) ), the independent model of the upper 5-layer structure of the conversion layer (height H) 2(5) The structural heights of each part are shown in Table 1 below: Table 1. Height information of the upper and lower structures of the transition layer S3: Apply a unit horizontal force to the top of each of the three independent models and calculate the corresponding lateral displacements Δ1 and Δ2. 2(4) , △ 2(5)As shown in Table 2 below: Table 2 Lateral displacement of the top of the structure under unit horizontal force S4: Through the lower structure height H1 at H 2(4) and H 2(5) Linear interpolation between the two values ​​is used to calculate the lateral displacement Δ of the superstructure at height H1. * 2. As shown in Table 3 below: Table 3 Lateral displacement of the improved superstructure S5: The improved equivalent stiffness ratio is calculated, as shown in Table 4 below: Table 4 Improved equivalent stiffness ratio γ * e Calculation results S6: Verify the improved equivalent stiffness ratio γ * e Whether the calculated values ​​meet the limit requirements of the standard for the equivalent stiffness ratio of partially frame-supported shear walls; according to Appendix E.0.3 of the Technical Specification for Concrete Structures of High-Rise Buildings JGJ 3-2010, the improved equivalent stiffness ratios in the X and Y directions of this embodiment are 1.3287 and 1.0815, respectively, which are close to 1 and greater than 0.8, meeting the requirements of the standard, and the next structural design work can be carried out.

[0021] Appendix Figure 7 The figure shows a comparison between the improved equivalent stiffness ratio calculated using the above method and the equivalent stiffness ratio in the current standard, when the height of the conversion layer is adjusted from 2.600 to 8.400 m in this embodiment. As can be seen from the figure, as the calculated height H1 of the lower structure decreases, the stiffness of the lower structure gradually increases, and the overall equivalent stiffness ratio also increases. However, due to the change in the calculated height H2 of the upper structure, the equivalent stiffness ratio calculated strictly according to the current standard "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010 is only calculated when H1 equals H2. 2(n) and H 2(n+1) A sudden change occurs at the critical height, meaning the stiffness of the substructure increases, but the equivalent stiffness ratio decreases abruptly, which is clearly inconsistent with the normal pattern of stiffness increase and decrease in the substructure. The improved equivalent stiffness ratio better reflects the relative ratio of the stiffness of the substructure to the upper structure of the transfer layer, aligning with the normal pattern of stiffness increase and decrease in the substructure of the transfer layer. This avoids abrupt changes, misjudgments, and underestimation of the stiffness of the substructure of the transfer layer caused by calculating the height at the critical height.

Claims

1. An improved calculation method for the equivalent stiffness ratio of a partially frame-supported shear wall structure system, comprising the following steps: S1: Based on BIM technology, establish an overall calculation model of the building structure according to the building layout drawings and functional requirements; S2: Based on the overall structural calculation model, separate independent models are created for the lower part of the transfer floor, the upper n-story structure, and the upper n+1-story structure. The height of the lower part of the transfer floor independent model is H1, and the height of the upper n-story structure independent model is H. 2(n) The height of the independent model of the n+1 layers above the conversion layer is H. 2(n+1) And H 2(n) ≤H1≤H 2(n+1) ; S3: Apply the same unit horizontal force to the top of the independent models of the lower structure of the transfer layer, the independent models of the n upper layers of the transfer layer, and the independent models of the n+1 upper layers of the transfer layer, respectively, and collect the corresponding lateral displacements Δ1 and Δ2. 2(n) and △ 2(n+1) data; S4: Due to floor height restrictions, the height of the upper structure cannot be the same as that of the lower structure. The heights H1 and H2 should be determined according to the specifications in the "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010. 2(n) and H 2(n+1) The linear proportional relationship between them is expressed in 1 / Δ 2(n) and 1 / △ 2(n+1) The improved lateral displacement Δ of the superstructure is obtained by linear interpolation between the two values. * 2. The specific calculation formula is as follows: （1） S5: Calculate the improved equivalent stiffness ratio. The calculation formula is shown below: （2） S6: Verify the improved equivalent stiffness ratio γ * e Check whether the calculated value meets the limit requirements for the equivalent stiffness ratio of partially frame-supported shear walls in the "Technical Specification for Concrete Structures of High-Rise Buildings" JGJ 3-2010. If it does, proceed to the next step of structural design. If it does not, return to step S2, adjust the structural layout and reset the various indicators until the requirements of the specification are met.

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