Prediction Application and Back Analysis to Earthquake Engineering

This chapter presents some interesting case studies of real earthquake engineering problems, most of them in Japan. The focus is on practical applications and special attention is paid to describing the seismic input. Earthquake response analyses are mainly performed for three practical purposes; i.e. prediction for plans of disaster prevention, seismic design, and prediction/back analysis. The Equivalent Linear Method (ELM) is the most commonly used method to calculate input motion from bedrock to the base of the structures and/or soil ground behavior under earthquake from given earthquake motion at bedrock considering material nonlinearity of soil. In order to overcome this deficiency of ELM, “Cycle-Wise Equivalent Linear method” was introduced. The method modifies the soil parameters during a half-cycle of stress/strain history in the time domain to model progressive damage such as liquefaction problem.