SIMPLE ESTIMATING METHOD OF MAXIMUM AXIAL STRAIN OF IRREGULARLY-SHAPED GROUND DURING EARTHQUAKE ASSUMING CONSERVATION OF ENERGY

Abstract

This study proposes a simple estimating method of maximum axial strain of irregularly-shaped grounds during earthquake. Two types of irregular-ground models; a ground with stepped bedrock and a ground with stepped surface, are considered. The maximum axial strain is estimated from the difference in velocity responses at the horizontal both ends assuming the conservation of energy. The difference in velocity responses is calculated by two SDOF model and two horizontally layered models. A modification factor is also proposed for the ground with stepped bedrock. It is found that estimated maximum strain using the horizontally layered models has higher accuracy, and the validity of modification factor is confirmed.