Study on the displacement response of structures due to hanging wall effects

The response of structure in the region near an active fault is dramatically influenced by the near-field effects, such as the hanging wall. In this paper, the characteristics of elastic and inelastic displacement response of structure due to these effects are investigated. According to this study, the amplification of absolute displacement response of hanging wall effects is significant in the short period range, while that of the foot wall effects is significant in the long period range. Although high peak ground accelerations are observed on hanging wall stations, the relative inelastic displacement response of the hanging wall ground motions is larger than foot wall ground motions only in very long period range. Larger relative inelastic displacement response is found in the short and medium period ranges of the foot wall effects. Compared with far-field ground motions, the high relative inelastic displacement capacity is needed when ground motions are influenced by hanging wall and foot wall effects. In some cases, unsafe results may be obtained in the evaluation of existing structures located in near-field regions when the relations of relative inelastic displacement is adopted for far-field ground motions.