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(中國建筑科學研究院有限公司, 北京 100013)
摘要: 按照《建筑隔震設計標準》 (GB/ T 51408—2021)規(guī)定,隔震層下部結(jié)構(gòu)的承載力驗算,應考慮上部結(jié)構(gòu)傳來的軸力、彎矩、水平剪力以及由隔震層水平變形產(chǎn)生的附加彎矩. 從 Timoshenko 梁單元剛度矩陣出發(fā),推導了考慮彎剪耦合的連接單元剛度矩陣及非線性內(nèi)力算法;開發(fā)了考慮彎剪耦合及二階效應的隔震支座單元,通過典型算例分析了彎剪耦合及二階效應對支墩彎矩的影響. 以實際隔震結(jié)構(gòu)為例,分析了隔震支座彎剪耦合及二階效應對隔震支座相連構(gòu)件內(nèi)力、配筋及結(jié)構(gòu)整體指標的影響. 結(jié)果表明,考慮隔震支座彎剪耦合及二階效應對隔震支座上支墩、下支墩及與其相連梁的內(nèi)力及配筋影響顯著,但對隔震結(jié)構(gòu)層間位移角、層間剪力及隔震支座耗能的影響較小. 在進行隔震層設計時,建議采用考慮彎剪耦合及二階效應的隔震支座單元進行隔震層的直接分析設計.
關鍵詞: 隔震支座; Timoshenko 梁單元; 彎剪耦合效應; 二階效應; 直接分析設計
中圖分類號:TU311 文獻標志碼:A 文章編號: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
∗中國建筑科學研究院有限公司青年科研基金項目資助(20210122331030008).
第一作者:喬保娟,博士研究生,高級工程師,主要從事結(jié)構(gòu)抗震研究及計算機仿真,Email:qiaobaojuan@ cabrtech. com.
[引用本文] 喬保娟,楊志勇,肖從真,等. 隔震支座彎剪耦合及二階效應的影響研究[ J]. 建筑結(jié)構(gòu),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.
