摘要
为研究填充墙对RC框架结构抗震性能的影响,以2008年汶川地震中倒塌的漩口中学教学楼为研究对象,制作了缩尺比为1∶4的模型并实施振动台试验.将汶川地震中卧龙台获得的地震波作为激励输入,获得了不同地震峰值加速度下结构的加速度响应、位移响应以及各柱端的应变响应,探讨了填充墙对结构抗侧刚度的影响,分析了结构在双向地震作用下的扭转效应,比较了约束条件不同的框架柱在相同时刻柱端应变的大小,展示了结构倒塌过程中各构件的破坏形态.研究表明,填充墙的开洞形式对结构刚度有显著影响;由于横向满砌填充墙的约束作用,即便在双向地震作用下,偏心结构也未产生明显的扭转效应;不同于传统"层屈服机制"的破坏模式,非对称设置的半高连续填充墙会导致地震剪力在各框架柱上分配不均,各构件呈现"次第失效"的破坏过程,这种倒塌机理概括为"凝震聚力,个个击破",即受半高连续填充墙约束的柱,其自由高度小,抗侧刚度大,分配到的地震剪力多,会率先在柱端形成塑性铰后因承重失效而使结构整体倒塌.
According to the construction drawings of the prototype structure which was the main building of Xuankou Middle School and collapsed in Wenchuan earthquake,a 1/4 scale reinforced concrete(RC)frame model with all kinds of infilled walls was built to conduct the shaking table test on collapse mechanism of RC frame with continuous half-height infilled walls.The dynamic responses about accelerations,displacements and strains of the model under different peak ground accelerations(PGA)were obtained by inputting the earthquake records from Wolong seismostation in Wenchuan earthquake to the model.Then the stiffness of the structure led by infilled walls was discussed,the torsional effect of the structure suffered from earthquake along two horizontal directions was analyzed,the strains of frame columns with different infilled walls were compared,and the collapsed RC frame was reappeared.The types of infilled walls have a significant effect on the stiffness of the structure.Though the centroid and rigidity center of the structure do not coincide,no torsion occurs because of the restraints from the full-filled walls.Given the only longitudinally translational motion,seismic shear forces were distributed according to the stiffness of the columns.Highly concentration of internal forces induced by bad configuration with half-height continuous infilled walls(spandrel walls)occurs and key weight-bearing members fail one after one.Then the structure finally collapses.It is different from the"side sway mechanism",which does not take the infilled walls into account.
作者
王波
郭迅
宣越
孙治国
WANG Bo;GUO Xun;XUAN Yue;SUN Zhiguo(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Key Laboratory of Building Collapse Mechanism and Disaster Prevention,Institute of Disaster Prevention,China Earthquake Administration,Sanhe 065201,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2021年第3期656-668,共13页
Journal of Basic Science and Engineering
基金
国家重点研发计划项目(2016YFE0205100,2018YFC1504302-3)
国家自然科学基金面上项目(51478117)
中央高校基本科研业务费专项(ZY20160107)
关键词
框架结构
抗震性能
填充墙
结构倒塌
振动台试验
内力分配
扭转效应
RC frame
seismic capability
infilled walls
collapse mechanism
shaking table test
distribution of seismic forces
torsion
