Reliability analysis of damping estimation by random decrement technique for high-rise buildings

Damping ratio is one of the most important parameters in the dynamic analysis of high-rise buildings for structural design. As a practical damping estimation method, the random decrement technique (RDT) has been widely applied to civil structures in the past decades. The inherent limitation of the RDT is that it can only provide a single optimal damping result, while the reliability of its estimated result is unavailable. By combining the RDT with the bootstrap method, this paper presents a reliability analysis scheme for damping estimation. Based on the bootstrap-based scheme, the reliability of damping results estimated by the RDT using four commonly used triggering conditions is systemically investigated through numerical simulations. The results show that the reliability of damping estimates can be effectively evaluated by providing the confidence interval. Moreover, based on free vibration test results and field measurements of acceleration responses of a 600-m high skyscraper during a typhoon, the bootstrap-based scheme is further verified to be applicable and effective for evaluating the reliability of damping results of high-rise buildings in field measurements. This paper aims to provide useful implications for evaluating the reliability of damping estimates and thereby improve the accuracy of damping evaluation of high-rise buildings.