Parameter Changes On The Seismic Response Characteristics Of The Curved Bridge With High Piers

With the rapid development of highway construction,curved bridges with high piers have been the main bridge type which could across the mountains,rivers and deep canyons.But from the relevant research materials of the seismic response characteristics at home and abroad,the analysis results of various design parameter changes on the seismic response characteristics of the curved bridge with high piers is less.It is unable to provide sufficient theoretical support for bridge aseismatic design,so it is very necessary to evaluate the seismic response characteristics of the curved bridge with high piers accurately and comprehensively.This paper has taken the WuJiaWan bridge in Guizhou province as the engineering background and established four kinds of finite element parametric models including the design parameters of the upper structure and the lower structure,the ground motion parameters and the seismic isolation bearings.The design parameters of the upper structure include radius of curvature,ratio of side to main span and height-span ratio.The design parameters of the lower structure include the high and low piers,the pile-soil-structure interaction and the center distance of the double thin-wall piers.The ground motion parameters include the ground motion input direction and the traveling wave effect.The seismic isolation bearings have compared the seismic effect of four kinds of bearings including pot rubber bearing,high damping rubber bearing,lead rubber bearing and friction pendulum isolation bearing which are used for the curved bridge with high piers.The first three kinds of parameters have been inputted the E1 seismic action and the seismic isolation bearings inputted the E2 seismic action.The first two kinds of parameters have considered the lateral seismic wave input and the longitudinal seismic wave input and the seismic isolation bearings considered the combined working conditions of the longitudinal,lateral,vertical seismic wave input.The time history analysis method has been used to calculate and analyze the seismic response influences of various parameters of the curved bridges with high piers.(1)Through the sensitivity analysis of the design parameters of the upper structure and the lower structure,the conclusion has been got which these parameters have influences on the natural frequency,the internal force and the displacement of the curved bridges with high piers and the degree of influences are different depends on the different design parameters and the different parts of the bridge.(2)In the sensitivity analysis of the ground motion parameters,both the ground motion input direction and the traveling wave effect have great influences on the internal force of the bridge.The traveling wave effect has greater influences on the displacement than the ground motion input direction significantly.(3)After setting the seismic isolation bearings,namely high damping rubber bearing,lead rubber bearing and friction pendulum isolation bearing,the natural frequency of the curved bridge with high piers has been decreased.Compared with pot rubber bearing,the seismic isolation bearings have reduced the seismic response in the three different ground motion input directions,among the effect of friction pendulum isolation bearing is slightly better than the other two kinds of seismic isolation bearings.