The Research On Anti Seismic Design Of Urban Bridges

Earthquake is a kind of natural disaster which will severely impair human society. If the earthquake caused damage to the traffic line, it would bring great difficulties to the rescue work, and affect the recovery work after the disaster. Bridge engineering is the throat of the transportation line and its seismic design is particularly important.Based on the seismic design and the computing needs in the design process of city overpass bridge which is under construction in Zhengzhou, and the seismic research of concrete bridges at home and abroad, the research on the seismic design of the city concrete bridge has been made and the following conclusions have been drawn:(1) When the bridge design adopts the ductility design, the foundation needs the ability to protect the component design, in which the pile foundation is small. It can not meet the seismic demand, and furthermore the whole project cost will increase greatly. Thus, ductility design is not feasible.(2) Seismic isolation design can be adopted. Under E2 erthquake force, the bending moment and shear force of the pier column, pile foundation and pile cap can meet the requirement of the current code, and the shear deformation and stability of the seismic isolation bearing can meet the requirements of the standard.(3) Because the isolation bearing is soft, relatively large displacement may occur between superstructure and piers, which will cause the collision of transition pier joints and the falling of beams. So rubber pad devices are suggested to be installed in the adjacent ends of main beams to reduce the risk of collision between the main girders.