Study On Seismic Appraiser And Strengthening Of Gravity Type Bridge Pier

Bridge structure is the important project to transportation. If it is destroyed by the earthquake, it will bring serious inconvenience for dealing with emergencies and providing relief after the earthquake. It has been think the object of scholars to study. Pier is an important part of bridge structure. It has become a focus of seismic research work because of it wide range damage under the earthquake.The gravity type bridge pier with heavy deadweight, high stiffness and the large force when it suffering the earthquake. It rarely has been used into the actual project, but it had been used in the early days. So, it has a large proportion in railway bridges. Some of them locate in the high earthquake intensity regions.The code for seismic design of railway engineering has been promulgated and implemented. So there are many aspects have changed such as site assessment division standard, site classification and so on in the new code. Therefore, the gravity pier will not meet the new code demands of the seismic design. We must use the mode n seismic design method to assess their seismic performance in this moment. If their seismic performance can not meet the needs, we should strengthen and reinforce the pier for ensuring safety of pier.This thesis based on some experiments and theories did by some predecessors. Using midas civil 2010 software to analysis of pier. We evaluate the seismic performance in different earthquake design intensity. If the pier's seismic performance is inadequate, we should strengthen the pier through CFRP materials and evaluate the seismic performance.Using this materials can be found that the pier's seismic performance and ductility have improved after reinforcement. We ensure the pier can not be destroyed under the earthquake effect. The content of the thesis is the following:1. Introduce details from the static pushover analysis method basic principle, basic assumption analysis steps, several common methods of analysis and common lateral load pattern mode.2. Detailed introduce using CFRP material for strengthening the concrete technical advantages, classification the physical properties, reinforcement mechanism of CFRP material, their scope of application and the construction characteristics.3. Using the gravity type bridge pier in railway lines analyze the pier which is reinforced by CFRP or not. Respectively calculate the moment-curvature relationship, natural vibration period, capacity curve, and evaluate the seismic performance in different design earthquake intensity. The result illustrate that the seismic performance will be improved after reinforcement. Using the reinforcement method through CFRP have been proved feasibility and validity.