Effects of nonlinear soil modeling on seismic ground response at Macao

摘要

A study of seismic ground response in Macao, including site investigation, measurement of shear wave velocity of local soils and, preliminary analysis of seismic ground response was carried out in recent years. In particular, this study is to examine the effects of nonlinear soil modeling on ground response at Macao. To obtain the difference between the predictions linear and nonlinear procedures, site response analyses for some representative sites were performed using the one-dimensional equivalent linear (PROSHAKE) and the nonlinear (D-MOD2000) seismic site response codes. The model parameters for nonlinear analysis were estimated based on the modulus degradation and damping curves selected for different soils in Macao. The study showed that while the equivalent linear procedure gave results comparable to those from the nonlinear procedure, the difference on response spectra becomes more significant when the maximum acceleration for the input motion is larger than 0.3g. Three site classes were proposed based on the parameter Vs30, and the results of these analyses were then developed as normalized design spectrum for different kinds of soil conditions in Macao.