摘要
对大跨度空间结构进行三向正交地震动多点激励下的非平稳随机地震反应分析。建立了多维多点随机非平稳地震动激励下的地震反应分析方法,并针对大跨度空间结构引入了波前法进行简化计算。数值仿真分析了天津奥林匹克中心体育场屋盖结构分别在一维随机地震动或三维随机地震动的一致激励、行波激励以及考虑部分相干效应和地震非平稳性的多点激励下的地震反应,结果表明:考虑地震动空间效应会使结构控制杆件内力增大约30%;考虑部分相干效应会使结构杆件内力变化约10%;考虑多维地震输入会使结构控制内力增大约15%;考虑地震动的非平稳性会使结构杆件内力减小约35%。由此可以得出结论,对于大跨度空间结构的地震反应分析,必须考虑地震动的多维输入和多点激励;然而不考虑地震动的非平稳性,其抗震设计偏于安全。
The non-stationary random seismic analysis of long-span spatial structures under multi-support excitations of three-dimensional orthogonal earthquake motion was performed. A method for seismic analysis of the multi-support excitations under the three-dimensional non-stationary random earthquake motion was established, and a simplified calculation for the long-span spatial structures was carried out with the wave-front method. The seismic responses of the roof structure of the Tianjin Olympic Center Stadium subject to the uniform excitation, the traveling-wave excitation, and the multi-support excitation considering the partial coherence effect and the seismic nonstationarity, under one-dimensional and three-dimensional random earthquake motions were numerically simulated. The results show that the axial forces of the control bars may be increased by about 30% when considering the three-dimensional effect of earthquake motion, or changed by about 10% when considering the partial coherence, or increased by about 15% when considering the three-dimensional earthquake excitation, or decreased by about 35% when considering the nonstationarity of earthquake motion. A conclusion was given that the multi-support and multi-dimensional earthquake excitations must be considered in the seismic analysis of the long-span spatial structures, and the seismic design is secure when the nonstationarity of earthquake motion is not considered.
出处
《工程力学》
EI
CSCD
北大核心
2007年第3期97-103,共7页
Engineering Mechanics
基金
国家杰出青年科学基金(50425824)
国家自然科学基金(50578109
50278064)
天津市科技发展计划(043112111)
关键词
大跨度空间结构
随机地震分析
多维输入
多点激励
非平稳地震动
波前法
long-span spatial structure
random seismic analysis
multi-dimensional excitation
multi-support excitation
non-stationary earthquake motion
wave-front method
