The Safety Evaluation Of Bridge Pier For The Ductility Seismic Design

As the key of the transportation system.the bridges once destroyed in the earthquake will lead to traffic gridlock,which will cause huge economic losses and seriously affect seismic disaster relief work. Therefore, it is of great importance to study the safety evaluation of the ductilitile bridges to ensure their safety of anti-seismic.On the base of ansysing the basic concepts of the ductility design of Bridge for seismic, bridge failure analysis and the Performance Factors of ductility, use the method of fuzzy similar optimal selection, static nonliner analysis method and dynamic time history analysis to evaluate the performance of ductility of the bridge. The main contents include the following:1. Based on fuzzy theory, the combination of qualitative and quantitative mathematical method-fuzzy optimization method can quickly achieve the safety evaluation of ductile seismic design of bridges. The method can consider the influence of a variety of uncertainties, aplying to extracting feature from existing tests, acquiring knowledge to achieve the evaluation of the target.2. According to the bridge seismic codes of several major countries, study the relationship between axial force and bending moment,relationship between moment and curvature, yield displacement,ultimate displacement and ductility coefficient indexes such as curvature ductility and displacement ductility of every designed pier of minimum reinforcement ratio in the country under different sections, differethent heights of piers and different pier loads, and analyze the law of variation.3. By the way of static nonliner analysis method, analyze the relationship between shear and displacement of every designed pier,and furthermore evaluate the performance of safety in different earthquakes by the performance point which is the intersection point of demand spectrum and capacity spectrum.4. By the way of dynamic time history analysis, analize the response of the top displacement,the base shear and moment of piers of different sections and heights under a specific earthquake.