Development of a Rotation Algorithm for Earthquake Damage Diagnosis

Abstract

In the attempt to develop simple damage detection algorithms that can be embedded in structural monitoring systems for rapid condition assessment following a large earthquake, a new algorithm is developed that characterizes structural damage, based on the residual drift following a strong motion. The residual drift is estimated from rotations computed from strong motion structural response acceleration measurements taken at key points on the structure. The Paulay and Priestley (1992) plastic hinge model is used to evaluate the residual drift, given rotation measurements at points on a single column. The algorithm is tested using data collected from a set of reinforced concrete single-column shaking tests, performed at the University of Nevada, Reno, and the University of California, Berkeley. Results from the tests indicate that the rotation algorithm can potentially be used for detecting and quantifying damage to single-column structures using one rotation measurement. Additional calibration and further testing of the algorithm will be necessary to reduce possible overestimation of the residual drift present on the column due to the simplicity of the column deformation model. Nevertheless, the results serve as an initial proof of concept that can be useful and very practical as a rapid damage estimation technique.