杭州市市民中心工程是一高位隔震大跨度多塔连体结构,6个主塔楼在高位采用隔震支座与6个大跨度钢结构连廊连接成一整体,整个连体结构外环周长达606m,故有必要进行多维多点输入地震反应分析。采用谐波叠加方法和快速傅里叶变换技术,合成了与建筑抗震设计规范(GB 50011—2001)反应谱相吻合的空间相关地震波,同时提出采用相关函数对人工模拟地震波在时域内进行检验的方法。利用模拟地震波对该工程进行多维、多点激励下的非线性时程分析,结果表明:在双向地震动作用下,考虑多点激励会使连廊杆件轴力、连廊与主塔楼间的隔震支座位移有较大增加,其中行波效应影响尤为明显,但多点激励对主塔楼内力和位移影响很小。
Hangzhou Citizen Center is a circular multi-tower connected structure with an outer circumference of 606m,and six high-rise towers are connected with large-span steel truss corridors by isolators at high positions.Spatially variable ground motions corresponding with the design response spectrum of national seismic design code(GB 50011—2001) are generated by using harmonic wave superimposing method and fast Fourier transform technique,and a method using correlation function to check the simulated seismic wave is presented.The nonlinear seismic responses of the structure under multi-support excitations of bilateral horizontal orthogonal seismic actions are numerically simulated by time history analysis.The results show that the axial forces of the steel truss bars and isolation bearing displacements increase,the wave passage effects are especially prominent,however,the displacements and internal forces of the towers vary only slightly,under multi-support excitations.