Simulation of spatial correlative ground motions based on a new separation method to decompose the power spectrum matrix
WU Zuoju;ZHANG Jianjing;WANG Zhijia;LIU Feicheng;DENG Xiaoning;Sichuan Institute of Building Research;Corporation of Chinese Nuclear Industry and Geotechnical Engineering in Zhengzhou City;Department of Civil Engineering,South-west Jiaotong University;
A new method was proposed in this paper for the first time to decompose the power spectrum,which separated the imaginary part from the power spectrum matrix,then just a real matrix had been left,and only needed to decompose the real matrix. Compared with the traditional Cholesky decomposition,this method is simple in calculation and become more accurate,so it has an obvious advantage over the traditional method. In addition,the feasibility of this matrix separation method is derived,and the detailed proof process was given at the same time.Through a synthetic examples in this paper,it can be seen that the ground motion has a good spatial correlation which generated by this method. At last,the analysis results confirmed that this ground motion showed double nonstationary characteristic not only in time domain but also in frequency domain.