摘要
掉层框架结构由于底部竖向构件不等高接地约束,在地震作用下上接地端构件破损严重,震后修复困难。为研究钢筋混凝土(reinforced concrete,RC)掉层框架结构震后残余变形及控制,按现行规范设计6个不同形式的RC掉层框架结构算例,采用OpenSees建立有限元模型并验证其有效性的基础上,进行非线性动力时程分析,考察了掉层框架结构在不同强度地震作用下的残余变形规律,对布置自复位防屈曲支撑(self-centering buckling-restrained brace,SCBRB)的掉层框架结构的震后残余变形和自复位性能进行了研究。研究结果表明,掉层结构的残余层间位移角和最大层间位移角有着相同的分布规律;为达到较好地控制残余变形效果,SCBRB可同时在掉层侧和上接地侧对称布置;增大SCBRB预应力筋的预张力有利于降低掉层结构的梁柱损伤程度,但不宜过大,建议自复位比取1.2左右;合理设置SCBRB能显著提升结构抗震性能,相较于无控结构,SCBRB-掉层结构的最大层间位移角和残余层间位移角减小幅度分别在38%~48%与88%~95%。
Due to the unequal restraint of the vertical members at the bottom of the frame structure supported by foundations with different elevations(FSSFDE),the upper grounding end members were seriously damaged under the earthquake action,and it was difficult to repair them after the earthquake.In order to study the post-earthquake residual deformation and control of RC FSSFDE,six examples of RC FSSFDE with different forms were designed according to the current code.The finite element model was established using OpenSees and its effectiveness was verified.The nonlinear dynamic time history analysis was conducted to investigate the residual deformation patterns of the FSSFDE under different seismic intensities.The post-earthquake residual deformation and self-resetting performance of the FSSFDE with self-centering buckling-restrained brace(SCBRB)were investigated.The results show that the residual inter-story displacement angle follow the same distribution law as the maximum inter-story displacement angle of the FSSFDE.In order to achieve a better control of residual deformation,SCBRB can be symmetrically arranged on both the layer drop side and the upper ground side.Increasing the pretension of the SCBRB prestressed tendon is conducive to reducing the damage degree of the beams and columns of the FSSFDE.However,it should not be excessive,and a self-centering ratio of around 1.2 is recommended.Reasonable installation of SCBRB can significantly improve the seismic performance of the structures.Compared with uncontrolled structures,the reduction in maximum inter-story drift angle and residual inter-story drift angle of the SCBRB-FSSFDE ranges from 38%to 48%and 88%to 95%.
作者
韩军
邓斌
张霆
刘立平
李英民
HAN Jun;DENG Bin;ZHANG Ting;LIU Liping;LI Yingmin(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Chongqing University,Chongqing 400045,China)
出处
《地震工程与工程振动》
北大核心
2025年第6期129-140,共12页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金面上项目(52278481)。
关键词
掉层框架结构
残余变形
自复位防屈曲支撑
抗震性能
frame structure supported by foundations with different elevations
residual deformation
self-centering buckling-restrained bracing
seismic performance
