RESEARCH ARTICLE Reliability Assessment of the Rotation Algorithm for Earthquake Damage Estimation

(Received 00 Month 200x; nal version received 00 Month 200x)A rotation algorithm was developed that estimates the slope of permanently de-formed columns using MEMS accelerometers. Previous studies by the authorsshowed that the algorithm can provide estimates of the residual displacement inthe column. This paper presents the determination of the functional form thatcan be tted to single columns, the optimal number of sensors, their locations,the veri cation of the statistical accuracy of the algorithm and the quanti ca-tion of the e ects of sensor noise and measurement error. The analysis is basedon the results of numerical simulations of reinforced concrete bridge columnspreviously tested experimentally. It is found that a fourth order polynomialand four sensors are sucient to capture the deformed shape. The residualdisplacements are estimated with 2% error at 50% con dence and 4% errorat 90% con dence. It is shown that with proper selection of sensor noise andsampling time, a minimum drift of 0.5% can be measured and 90% accuracywith 95