Application of endurance time method in seismic analysis of bridges

In this paper, the application of Endurance Time (ET) method to the seismic analysis of bridges is elaborated. ET method is a novel seismic analysis method based on time history analysis in which a structure is subjected to a predefined intensifying acceleration function. First, six concrete bridges were modeled in this study. Three Endurance Time Acceleration Functions (ETAFs) were applied to the models, and the average of responses was calculated. Next, the time history analysis was conducted using seven real accelerograms that are scaled using the method recommended by Federal Highway Administration (FHWA) to be compatible with the design spectrum of American Association of State Highway and Transportation Officials (AASHTO) guideline for a site with soil type C in Berkeley, California. The average of the responses of these analyses is considered as a reference. By scaling the mentioned accelerograms over a wide range of hazard levels, Incremental Dynamic Analysis (IDA) is performed. Finally, the comparison of the response of ET analysis and time history analysis and also the comparison of Endurance Time Analysis (ETA) and IDA curves revealed good agreement. The major advantage of ET method over time history and IDA methods is the need for less computational effort for performing the analysis. Such time efficiency was achieved due to the possibility of predicting responses by a smaller number of analyses despite maintaining the necessary accuracy. (C) 2020 Sharif University of Technology. All rights reserved.