Study On The Resistance Earthquake Of Zhongyi Bridge Of K6+238 In Lijiang City On The G214 Line Of Yunnan National Highway

The curvilinear beam-girder bridge mentioned in the thesis can be applied well to complex landforms,meet the linear shape of the entire route,smooth and smooth lines,and is widely used in domestic and international city interchanges and urban viaducts.Since the multi-span curved beam bridge collapsed in the two large-scale interchange projects in the San Fernando Earthquake in the United States in 1971,many scholars have conducted a profound exploration on the seismic response of the curved bridge.As of today,the research on the seismic resistance of the curved bridge has made great progress and has achieved many important achievements.This article summarizes the diseases that occur at home and abroad for curved beam bridges under earthquake loading,take the Yunnan National Road G214 line Lijiang City K6+238 Zhongyi Bridge as an engineering background,based on past scholars’ research,response Spectrum Analysis and Time-history Analysis of Curved Beam Bridges,the internal forces(especially bending moments)and displacements of the bridge under the E1 and E2 earthquakes have been obtained.The main work of this article includes:(1)Summarize the earthquake damage of the bridge structure and the stress characteristics of the curved beam bridge and study the design method of the curved beam bridge.(2)Summarize the seismic methods that are often used now,and focus on the response spectrum analysis method and time history analysis method.These two types of seismic analysis methods are used as the theoretical basis for the study of the seismic performance of bridges in this paper.(3)Using the finite element analysis software Midas Civil established the Yunnan National Road G214 line Lijiang City K6+238 Zhongyi Bridge full bridge calculation model,a reasonable simulation of the bridge boundary conditions and the imposed load,select the most unfavorable input direction and Its free vibration characteristics were calculated and analyzed.(4)Using the response spectrum method of bridge seismic design method,the E1 and E2 earthquakes with 8 earthquake-resistance and E2 earthquakes were analyzed.T he earthquake-resistance intensity was grade 9 E2 earthquake along the bridge directio n and horizontal direction.The main force of the bridge,the internal force of the pier,displacement.(5)The time-history analysis method of the bridge seismic design method was used to analyze the internal forces and displacements of the main beam and the bridge pier of the E2 earthquake with magnitude 8 earthquake-resistance and the horizontal and vertical direction.(6)Study the results of model analysis and compare them with the specifications to determine whether the bridge meets the design requirements.The improvement suggestions for the bridge are to appropriately increase the reinforcement ratio of the lateral pier and the diameter of the pier.