Form Selection And Earthquake-resistant Construction Of Beam Bridge In High Intensity Seismic Mountain Region

China is one of the earthquake-prone countries, which is located in multiple seismic activity zones. Earthquake brings us great casualties and property losses. The bridge as a lifeline project once damaged would create difficulties to the rescue work after earthquake, thus resulting in secondary disasters. So the ability of earthquake resistant of bridge is extremely important.In recent years, China strengthens the development of western highway construction. Because of the terrain, topography and other reasons, the bridge types of western mountainous areas are different from the types of plain areas. With the features of bend, slope, oblique, high etc, the force affordability of these irregular bridges is quite different from the regular bridges especially in earthquake; the detailed structure is an important part of the bridge earthquake resistant, whether the seismic design is appropriate plays a decisive role on the overall seismic performance of bridges. As a reasonable structure type and strong detailed structure can greatly reduce or even avoid the possibility of injury, this paper addresses the following points.Firstly, it describes the development process of seismic design and thestandard seismic, introduces the seismic design process, and elaborates the importance of bridge seismic design and the ductility index and factors affect ductility. The guiding significance of conceptual design to the bridge seismic design is elaborated as well. Using the conceptual design to make a reasonable selection on the structure type of top part and lower part,and connection form of detail part of bridge can effectively improve the seismic performance of structures and reduce the workload of seismic design.Secondly, with the irregular bridge in Simao～Lancang Road as the object of study, the paper uses SAP2000 finite element software to analyze the factors affect curved bridge and oblique bridge, and obtains the dynamic characteristics and seismic response features.Finally, the paper analyzes the factors affect overall layout of bridges, checks the influence of cross slope, longitudinal slope, radius, the height of the piers; the reasonable selection of different types of piers; the influence of different bridge deck surface structures on the force affordability of pier deck; the reasonable selection of block and beam clearance valuesand the clearance material; the reasonable selection ofvertical anti-fall device gap value and the stiffness.This essay studies the construction of piers in deep water, and provides the basis for seismic design of bridges through the above analysis and comparison.This paper is from the topic " the seismic research of Simao～Lancang highway bridge", which is the technology fund project of Department of Transportation in Yunnan Province (project number:KKK0201006076), meanwhile it has received the project fund.