Parameter Study on Seismic Random Model Based on Code for Design of Seismic of Electrical Installations

The spectral parameters of a seismic random model have been studied on the basis of the design response spectrum in the Chinese standard Code for design of seismic of electrical Installations(GB50260-96).First,the nonstationarity of the ground motion is represented with an envelope function,which defines the duration of the ground motion at same time.Then,the power spectral density(PSD) of the acce-leration at ground level is evaluated by an iterative approach according to the principle of equivalent peak acceleration.Finally,the Clough-Penzien acceleration spectrum is selected as a target function to calculate the PSD curve through nonlinear fitting on the parameters,such as earthquake intensity and site type,defined in the code.The results show that the Clough-Penzien spectrum can fit the PSD curve well.The spectrum parameters of the random model of ground motion are given in this paper,and they provide a re-ference for the selection of ground motion input.