In 2011 the Great East Japan Earthquake, many buildings prevented continued use by damage of foundation in spite of minor damage of superstructure. For continued use of buildings, seismic performance of foundation is important, not just seismic performance of superstructure. In this paper, I will report a case assumed that pile damage is caused by complicated dynamic characteristics of superstructure, and a study of the case used microtremor measurement, ARX model, and multi-degree-of-freedom system.
