A study of building response to ground vibration : ambient vibration approach

Abstract

In urban area where space is limited, it is unavoidable for construction works to be carried out near to existing structures. In such situation, the increasing risk of vibration-induced damage on the buildings can be seen and has to be managed appropriately. To alleviate the problem, there are three areas that measures can be taken: vibration sources, propagation mediums, and buildings subjected to vibration. This study focused on the last factor and tried to evaluate how buildings respond to ground motions by determining their transfer functions. The transfer function (TF) is the ratios between the output and input in frequency domain of a linear system. For ground-borne vibrations, the system is the soil through which elastic wave propagates and the output is the motion at any location of interest, for instance, on the surface or within the ground or anywhere in building subjected to vibration. In this study, twopoint measurements of ambient vibration were used to derive a transfer function between ground and building motions. Then, the obtained function was used to predict the response of the same building against vibration due to the demolition of nearby structures. By verification with vibration generated by a demolition work, the measured Peak Particle Velocities seem to be slightly underestimated by the proposed method. Nonetheless, the study showed that ambient vibration can be used to predict the building response with a moderate degree of determination.