摘要
为探究相邻结构动力相互作用(Dynamic Cross Interaction,DCI)体系在地震作用下的反应机理,对上海地区典型深厚软弱场地上包含两相邻12层带桩筏基础框架结构的DCI体系以及只含单个上述框架结构的土-结构动力相互作用(SoilStructure Interaction,SSI)体系进行了三维整体有限元分析。计算中土体的动力本构模型采用等效线性模型,利用三维粘弹性人工边界作为土体的侧向截断边界。研究了两种体系在动力特性和地震反应等方面的差异,DCI体系比SSI体系具有更小的自振频率,其差异有随着阶次增高而变大的趋势;DCI体系中上部结构加速度反应一般要大于SSI体系中的结构反应,顶部几层的差异大于底部几层;与此相反,DCI体系中地基土的加速度反应小于SSI体系中的土体反应,其差异在土表附近土体最为明显,DCI体系中两结构相邻之间且处于中点位置上土体的加速度反应最大;DCI体系中上部结构各楼层位移及层间位移反应相比SSI体系的增大幅度分布比较均匀。结果表明,深厚软弱场地上的DCI效应对整体结构地震反应有着重要影响,是不容忽视的。
To investigate the earthquake response of dynamiccross interaction(DCI) system,three-dimensional finite element analysis of DCI system and soil-structure interaction(SSI) system in time domain is carried out.DCI system consists of twin adjacent 12-strory frame structures with pile-raft foundation and surrounding soil,while SSI system consists of only single one and its surrounding soil.A typical deep soft site in urban district of Shanghai is chosen in the numerical simulation,and commonly used equivalent linearity model is taken as its dynamic constitutive law.Three-dimensional viscous-spring artificial boundary is implemented in ANSYS program.The comparisons between two systems in aspect of dynamic characteristic and earthquake response are made.In general,DCI system has smaller natural frequency and stiffness,and the difference tends to be larger in higher mode.The acceleration response of superstructure in DCI system is larger than that in SSI system,and this enlarging effect is more profound on top floors than the bottom.On the contrary,the acceleration response of soil in DCI system is often smaller than that in SSI system,and the most distinct diversity occurs at near-top-surface location.In addition,soil located at middle position in the adjacency direction of twin structures has the strongest acceleration response.As for displacement and relative displacement response,the extent of enlargement in DCI system is uniform along vertical direction.It is clearly shown that DCI effect has great influence on the seismicresponse of whole system on deep soft sites,and it cannot be neglected.
作者
陈金华
陈淑萍
耿少波
武晋文
Chen Jin-hua;Chen Shu-ping;Geng Shao-bo;Wu Jin-wen(College of Transportation Engineering,Wuhan Technical College of Communications,Wuhan 430065,China;College of Science,North University of China,Taiyuan 030051,China)
出处
《工程抗震与加固改造》
北大核心
2020年第2期77-86,68,共11页
Earthquake Resistant Engineering and Retrofitting
基金
武汉交通职业学院科研创新团队建设计划资助项目(CX2018B07)
国家自然科学基金项目(51504220,51408558)。
