Stochastic linear and nonlinear one-dimensional ground response analysis

During an earthquake, the amplitudes of seismic wave may amplify significantly as it propagates through the soil layers near the ground surface. The base motion generated during earthquake is a random phenomenon. The motion equation is a one-order propagation type of equation. This equation can be solved in either frequency domain or time domain. In this paper, the one dimensional motion equation is solved by finite element method in time domain. In this way, the selected soil stochastic parameters are shear wave velocity and unit weight. Stochastic analysis was carried out based on Point Estimated Method (PEM) is used. The stochastic response spectrum at the ground surface are determined for linear and nonlinear method. The result show that the nonlinear approach predicts closer response to real recorded data in comparison with the linear approach and showed that the standard deviation of acceleration response spectra decreases with increasing period.