Seismic Hazard Loss Evaluation Of Railway Bridge In Large Earthquake

In earthquakes, the traffic disruptions caused by the railway bridge damages, which will not only affect peopel’s daily life and economic operation, and result in serious economic losses, but also will have impacts on the relief work after earthquakes, thus may exacerbate the earthquake damages. Due to the lack of railway bridage seismic damage informations, the research for the railway bridge seismic damage losses, especially the railway bridge seismic damage loss assessment research, under large earthquakes, isn’t perfect. Therefore, the assessment new technology research for the railway bridge damages and losses caused by the large earthquakes, is of great significance to realize the rapid assessment for the seismic damage and losses of the railway bridge after the large earthquakes.Followings are the main works done in the thesis:1. Investigation, statistics research and analysis of railway bridge seismic damages caused by Tangshan and Wenchuan earthquakes. Research of investigation range, investigation contents and damage classification on the components, such as beam bodies, piers and supports of the concrete beam-type railway bridge in the earthquakes.Obtainment of investigation and statistics research methods for the concrete beam-type railway bridge seismic damages caused by the large earthquakes.2. Based on existing bridge seismic damage assessment methods, combined with the sujbet’s actual situation, this study focuses on the empirical statistical regression method. The statistical regression model in the railway bridge seismic vulnerability was adopted. In order to make the railway bridge seismic damage assessment method be applicable to rapid emergency work after the earthquakes, according to the selection principle of the seismic damage influence factors, the appropriate influence factors were selected, based on the railway bridge seismic materials of Wenchuan and Tangshan earthquakes. With the adopted least square method, the statistical regression model was established to calculate the damage index of concrete railway beam-type bridge, which includes the empirical formula, empirical coefficient, the index range to assess the earthquake damage classification, as well as the research for the loss rate of the railway bridge seismic damages.3. Based on the above empirical statistical regression model to assess the railway bridge seismic vulnerability, the visualized railway bridge seismic damage and loss assessment software was developed, with the VB6.0program. Then the instruction of the software was given. The reliability of the assessment software was confirmed with the bridge seismic damage.