Modal Identification of a Heavily Damaged 9-story SRC Building by Ambient Vibration Measurements

Abstract

Modal parameters of a building damaged heavily by the 2011 off the Pacific coast of Tohoku Earthquake were identified from ambient vibration data with frequency domain decomposition techniques (FDDT). The characteristics of the identified 3-D mode shapes were discussed with respect to the earthquake damages. Also, we identified the mode shapes by two kinds of FDDT; one for general viscous damping system, the other for proportional damping system. The influence of viscous damping condition on the identified mode shapes was discussed.