Long-term seismic monitoring of base-isolated building with emphasis on serviceability assessment

Seismic monitoring system provides opportunities to observe possible damage or failure and weakening of structural components and to evaluate serviceability performance of a structure during an earthquake. This can be achieved by comparing structure recordings before and after the event or by identifying significant change in characteristics of structural response that may serve as indicators of failure or damage in progress. Excessive vibration on some parts of structure may become a serviceability concern for some buildings, and this also can be detected from continuous monitoring. Several factors such as characteristics of ground motion, soil condition, and geometry of the structure could cause excessive localized structural vibration, and by evaluating the responses, one can take remedial action. For a base-isolated building in particular, reduction of response of upper stories is critical to protect nonstructural elements or sensitive equipments on the building. In this paper, we describe a case study on seismic monitoring of a base-isolated building with the main focus on evaluation of serviceability performance. The study emphasizes on a influence of building asymmetricity on the seismic response. Results of the study are based on a long-term building seismic monitoring program for over 3years between 2010 and 2012 under various amplitudes of earthquake including the March 11, 2011 Great East-Japan Earthquake. Copyright (c) 2014 John Wiley & Sons, Ltd.