Study on seismic evaluation of soil-pile-RC structure system based on equivalent linear analysis

This study examines the equivalent linearization analysis by a sway model which expresses a superstructure on pile foundations considering of the nonlinearity of a soil-pile system, and we propose the seismic evaluation method based on the above analysis. This seismic evaluation method consists of the decision of the failure mode of a superstructure and a pile foundation using the curve of relation of the ductility factor between a superstructure and a pile head, the evaluation of the ductility factor of a superstructure and a pile head by the equivalent linearization analysis, and the decision of the necessity of seismic reinforcement based on the result. In addition to this method, we propose another method consisting of the individual evaluation of the ductility factor without using the sway model. The proposed method is applied to a building which was damaged to pile foundations during the 2011 off the Pacific Coast of Tohoku Earthquake, and the validity of the method is confirmed by this examination.