摘要
地基不均匀沉降可能会引起沉降范围内部分隔震支座发生转动,造成隔震层刚度发生变化,进而导致上部结构地震损伤和失效风险增大。针对地基不均匀沉降条件下基础隔震结构地震响应研究,现有成果大都通过施加平动位移进行模拟,并未考虑隔震支座转角的不利影响。为了研究地基不均匀沉降条件下基础隔震结构支座可能出现的转动及其对整体结构地震响应特征影响规律,首先以隔震支座为对象,研究了支座转动变形与叠层橡胶隔震支座水平刚度变化关系,建立了叠层橡胶隔震支座转角与水平刚度变化关系函数;在此基础上系统研究了地基不均匀沉降条件下整体基础隔震结构响应特征,以及基础结构的减震系数变化规律,以期揭示地基不均匀沉降对基础隔震结构地震响应影响机理。结果表明:隔震支座转角变形会引起隔震结构体系地震响应发生显著变化,随着隔震支座转角增大,隔震层水平刚度增大的同时隔震结构体系变形能力减弱,进而造成上部结构加速度响应增大,位移响应减小,导致基础隔震结构水平减震系数增大,减震效果低于预期;当转角接近π/2时,隔震支座将丧失降低上部结构地震响应的作用,原隔震结构将退化为抗震结构;对于存在地基不均匀沉降的基础隔震结构,应及时采取必要措施控制地震响应,以防范上部结构发生倾覆。
The uneven settlement of the foundation may cause the rotation of the seismic separation support within the settlement range,resulting in a change in the stiffness of the seismic isolation layer,and thereby increasing the risk of seismic damage and failure of the superstructure.For the study of seismic response of base-isolated structures under the condition of uneven foundation settlement,most of the existing results are simulated by applying translational displacement,and the adverse effects of the rotation angle of the base-isolated support are not considered.To examine the possible rotation of the support of the base-isolated structure under uneven foundation settlement and its influence on the seismic response characteristics of the overall structure,with the seismic isolation support as the object firstly,the relationship between rotation deformation of the support and the horizontal stiffness change of the laminated rubber isolation support is investigated,and the relationship between the rotation angle of the laminated rubber isolation support and the horizontal stiffness change is established.On this basis,the response characteristics of the overall base-isolated structure under uneven foundation settlement and the variation law of the damping coefficient of the base structure are systematically explored to reveal the mechanism of the impact of uneven foundation settlement on the seismic response of the base-isolated structure.The result shows that the angular deformation of the seismic isolation support causes significant changes in the seismic response of the structure.As the rotation angle of the seismic isolation support increases,the horizontal stiffness of the seismic isolation layer increases,while the deformation capacity of the seismic isolation structure system decreases,which in turn causes an increase in acceleration response of the superstructure and a decrease in displacement response.As a result,the horizontal damping coefficient of the base isolation structure increases,and the damping ef
作者
包超
闫东琦
张宇航
吕大海
马肖彤
林加胜
BAO Chao;YAN Dongqi;ZHANG Yuhang;LYU Dahai;MA Xiaotong;LIM Kar Sing(School of Civil Engineering and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;School of Civil Engineering,North Minzu University,Yinchuan 750021,China;Department of Civil Engineering,College of Engineering,Universiti Malaysia Pahang,Kuantan 26300,Malaysia)
出处
《防灾减灾工程学报》
CSCD
北大核心
2023年第3期535-542,共8页
Journal of Disaster Prevention and Mitigation Engineering
基金
宁夏回族自治区重点研发计划项目(2021BEG03022,2018BEG03009)
宁夏回族自治区重点研发计划项目(引才专项)(2018BEB04006)
宁夏青年科技人才托举工程(TJGC2019001,TJGC2019007)
宁夏高等学校科学技术研究项目优秀青年教师培育基金项目(NGY2020054)
国家自然科学基金项目(51778276)资助。
关键词
基础隔震结构
地基不均匀沉降
叠层橡胶隔震支座
支座转角
地震响应
base isolation structure
uneven settlement of foundation
rubber isolation bearing
initial rotation angle
seismic response
