(中国建筑科学研究院有限公司, 北京 100013)

摘要: 按照《建筑隔震设计标准》 (GB/ T 51408—2021)规定,隔震层下部结构的承载力验算,应考虑上部结构传来的轴力、弯矩、水平剪力以及由隔震层水平变形产生的附加弯矩. 从 Timoshenko 梁单元刚度矩阵出发,推导了考虑弯剪耦合的连接单元刚度矩阵及非线性内力算法;开发了考虑弯剪耦合及二阶效应的隔震支座单元,通过典型算例分析了弯剪耦合及二阶效应对支墩弯矩的影响. 以实际隔震结构为例,分析了隔震支座弯剪耦合及二阶效应对隔震支座相连构件内力、配筋及结构整体指标的影响. 结果表明,考虑隔震支座弯剪耦合及二阶效应对隔震支座上支墩、下支墩及与其相连梁的内力及配筋影响显著,但对隔震结构层间位移角、层间剪力及隔震支座耗能的影响较小. 在进行隔震层设计时,建议采用考虑弯剪耦合及二阶效应的隔震支座单元进行隔震层的直接分析设计.

关键词: 隔震支座; Timoshenko 梁单元; 弯剪耦合效应; 二阶效应; 直接分析设计

中图分类号:TU311 文献标志码:A 文章编号:1002-848X(2023)04-0128-07

DOI:10. 19701 / j. jzjg. LS202086

Study on influence of bending-shear coupling and second-order effect of seismic isolation bearing

QIAO Baojuan, YANG Zhiyong, XIAO Congzhen, QIU Hai

(China Academy of Building Research, Beijing 100013, China)

Abstract: According to the Standard for seismic isolation design of building (GB/ T 51408—2021), the axial force,bending moment, horizontal shear force from the upper structure as well as the additional bending moment caused byhorizontal deformation of the seismic isolation layer should be taken into account in checking the bearing capacity of thelower structure of the seismic isolation layer. Based on the stiffness matrix of Timoshenko beam element, the stiffness matrixof connection element and nonlinear internal force algorithm considering bending shear coupling were derived. A seismicisolation bearing element was developed considering the bending-shear coupling and second-order effect, and the influenceof the bending-shear coupling and second-order effect on the bending moment of the pier was analyzed through typicalexample. Taking an actual seismic isolation structure as an example, the influence of the bending-shear coupling andsecond-order effect of the seismic isolation bearing on the overall structural indicators, internal force and reinforcement ofthe structural members connected with the seismic isolation were analyzed. The results show that the bending-shear couplingand second-order effect of the seismic isolation bearing have significant effects on the internal force and reinforcement of theupper and lower piers and the connected beams of the seismic isolation bearing, but tiny effects on the story drift ratio,story shear force and energy dissipation of the seismic isolation bearing. When designing the seismic isolation layer, it isrecommended to use the seismic isolation bearing element considering the bending-shear coupling and second-order effectfor direct analysis and design of the seismic isolation layer.

Keywords:seismic isolation bearing; Timoshenko beam element; bending-shear coupling effect; second-order effect; directanalysis and design

∗中国建筑科学研究院有限公司青年科研基金项目资助(20210122331030008).

第一作者:乔保娟,博士研究生,高级工程师,主要从事结构抗震研究及计算机仿真,Email:qiaobaojuan@ cabrtech. com.

[引用本文] 乔保娟,杨志勇,肖从真,等. 隔震支座弯剪耦合及二阶效应的影响研究[ J]. 建筑结构,2023,53(4):128-134,127. QIAO Baojuan,YANG Zhiyong,XIAO Congzhen,et al. Study on influence of bending-shear couplingand second-order effect of seismic isolation bearing[J]. Building Structure,2023,53(4):128-134,127.