【摘要】 GB 50011—2010《建筑抗震设计规范》要求对于平面投影尺度很大的空间结构,应进行多点输入地震反应分析。在多点输入地震反应分析的主要方法中,时程分析法的应用最为广泛。在确定多点输入地震波时,主要考虑行波效应和局部场地条件效应。多点输入时程分析在有限元分析程序中的实现方法主要有两种,一是对各支座点施加强制边界条件,二是采用大质量法。据此,提出以超载单元和超载比作为多点输入对结构影响的主要评价指标,并根据多个实际工程多点输入分析的经验,给出了多点输入的一般性结论:多点输入将增加结构的扭转输入,因此对于边角构件的影响较大;多点输入降低输入的同步性,因此结构平动反应减小;在一定视波速范围内,多点输入影响随着视波速的减小逐渐增加;多点输入的影响随着楼层的增高而减小等。更多还原

【Abstract】 Based on the ’Code for seismic design of buildings(2010)’,seismic analysis under multi-support excitation should be done to structures with large dimension.The time-history seismic analysis method is popular among the main methods used for multi-support seismic analysis.In confirming the multi-support earthquake wave,the traveling wave effect and local site effect are two critical factors.Generally,there are two methods to make multi-support excitation analysis in finite element program.One is the compulsory boundary condition method,and the other is the big-mass method.The paper suggests taking the overload element and overload proportion as the evaluation index to the influence of multi-support seismic analysis.At the same time,some common conclusions are summarized in the paper based on the analysis experience of some projects.Such conclusions include that the torsion effect will be increased under multi-support seismic analysis and then result in adverse effect on the corner and side members.The earthquake input synchronization will be reduced under multi-support seismic analysis and then decrease the structure translational displacement.Generally,the influence of multi-support seismic analysis will be increased along with the reduction of traveling wave velocity while be decreased along with the increase of the building height.更多还原