Seismic Damage Assessment Of Railway Simply Supported Bridges After Large Earthquake

Tangshan Earthquake with magnitude7.8in1976and Wenchuan Earthquake with magnitude8.0in2008, were the most severe and destructive ones since the founding of new China, caused very high casualties and huge economic loss. This research is based on the survery of seismic damage of the concrete railway beam bridges in the two above mentioned earthquake. From the data of the survery, typical seismic damage features of railway simply supported bridges were summarized and they were the basis of the Quick Prediction and Quick Assessment which will be discussed in the following passage.After a big earthquake, railway beam bridges, as the lifelines of transportation, are very important to the rescue and relief work. Thus, it is essential to know the seismic damages of the bridges. The Quick Prediction Method can give a quick prediction of the seismic damage and economic loss of railway simply supported bridges at a macroscopic view. This method is based on the damaged bridge samples in the two earthquakes, and created by modelling the relationship between some seismic influence factors and seismic damage using empirical regression approach. The developed software, named Railway Bridges Seismic Damage and Loss Prediction System (v1.0), engaged with the functions of data import, data input, data modify, data erase, data check, damage calculation, loss analysis, etc, can be convenient for the quick prediction of bridge damage after an earthquake. Consequently, relevant departments can achieve a macro-understand ing of bridge damages.On the other side, Quick Predtion which based on the statistic method can be used to obtain a macro view of the damages of bridges but not the result of the assessment of a specific bridge. Therefore, a more precise method is needed to evaluation the real damage of the bridges. The Quick Assessment of the concrete railway simply supported bridges, mainly based on the survey and evaluation of the components of a bridge, can obtain the damage assessment result of the whole bridge. The theory of the method is based on the Analytic Hierarchy Process and Fuzzy Math, and it is scientific and accurate. Math program MATLAB is used to simulate and realize the process of Quick Assessment Method on a railway simply supported bridge.