Seismic Assessment Of Bridges Based On Pushover Analysis

As a vital lifeline engineering, bridge project, once damaged in the strong earthquake, the lives and property of the people suffer huge losses. China has tens of thousands of bridges, of which more than half of the seismic fortification intensity of seven degrees and above areas. In recent years, the earthquake investigation and study indicates that the the bridge structure built under earlier seismic design cords has a high seismic vulnerability. Therefore, for bridges built in the earthquake zone in the early times, using reliable seismic performance assessment methods, correctly assessing its seismic performance, and, accordingly guiding bridge seismic reinforcement to enhance the active-duty bridge seismic capability, minimizing the damage losses and enhancing the protection of people's lives and property, are of great significance.This paper tries to put on a new bridge seismic performance assessment method based on Code for seismic design of buildings (GB50011-2001). By calculating the damage index of bridges under small earthquake and rare earthquake, the seismic performance of the bridge structure can be evaluated. Studies presented in this thesis can be summarized as follows:1. The researchment of methods of seimic performance evaluation for bridge structutes demonstrates that a new method based on Pushover analysis is of great importance.2. In this thesis, the basic principle and the implementation steps of Pushover anlysis method are systemically discussed. In chapter 2, it focuses on the distributing patterns of lateral load, calculating the performance point and the pushover curve.3. This thesis discusses several seismic damage model in detail. And finally choose a single-and dual-parameter seismic damage model to deteiming the seismic damage index.4. This thesis detailed discussion of earthquake magnitude division, and introduced the relationship between earthquake magnitude division and seismic damage model to seismic assessment of bridges.5. The seismic capacity of both the full bridge and pier in transverse and longitudinal direction has been determined by the method introduced in this thesis.