Research On Appropriate Intensity Measure Of Tall Pier Seismic Performance Estimation

With the rapid development of social economy in our country, traffic facilities have been greatly improved. High pier bridge as the typical transport of new ages also has been developed. As the most important part of high pier bridge, the study of seismic capacity of high pier gets a lot of attention. With the unique mechanical properties of long thin and long period, in order to evaluate the seismic capacity of high pier, the paper consider the influence of higher modes on it, raising the intensity measure considering high modes--EIIM2&1 and studying its applicability to predict the seismic response of high pier structures.The paper chooses 53 real ground motion records to establish a record base, and three pier models with different natural period were established. Taking incremental dynamic analysis(IDA) to each model, obtaining the prediction values of strength parameters and dynamic time history analysis results of seismic response of high pier structures under the same ground motion record, drawing the IDA curves of each model and providing data reference.By IDA curves of high pier structure model, the paper uses a variety of statistical analysis methods to study the seismic capacity of high pier utilizingEIIM2&1. The paper takes following works:1. In view of the IDA curves of high pier model, contrasting the prediction by intensity measure of considering high modes influence or not, studying advantage of high pier seismic response prediction results considering higher modes.2. Analysising the effectiveness, sufficiency and proportional adjustment robustness of evaluation of seismic performance by using EIIM2&1 the of high pier structure considering higher modes influence, and then studying statistical applicability.3. Using the results of IDA, through the full probability method to draw the fragility curves of EIIM2&1 considering higher modes influence, obtaining the probability distribution of the three high pier models through three kinds of limit states, validating applicability of EIIM2&1 and providing reference data for actual engineering.The results indicate: EIIM2&1 can effective evaluate seismic capacity of high pier bridges both in theoretical analysis and practical application.