Seismic Performance Analysis Of A Single Tower Asymmetric Self-anchored Suspension Bridge

With the development of the city and the advancement of urbanization,due to the beautiful appearance,economic advantages and flexible site selection of self-anchored suspension bridges,the advantages of urban bridge selection are becoming more and more obvious,and gradually applied by engineering builders to actual urban projects.under construction.Due to the flexible span arrangement of the self-anchored suspension bridge,the self-anchored suspension bridge is applicable regardless of the general symmetric arrangement or the asymmetric arrangement,which fully embodies the adaptability and economic flexibility of the bridge type.For the single tower asymmetric self-anchored suspension bridge studied in this paper,due to the non-stacked span setting,the bridge type is coordinated with the surrounding environment and is more suitable for urban bridges.Compared with other suspension bridge type structures,the bridge type is selfanchored and asymmetrically spanned,so that the main tower is prone to asymmetric loading under the equilibrium state and load condition of the bridge.The beam section is unevenly stressed.The force characteristics and bridge characteristics of the single tower asymmetric self-anchored suspension bridge make the overall force law of the bridge type change greatly compared with the ground anchor suspension bridge.Therefore,the seismic performance evaluation of the structure is also different from the general suspension bridge.At the same time,it is important to evaluate the seismic performance of the bridge type more accurately and comprehensively to ensure social property and life safety.Based on the calculation example of Hunan Zhaohua Xiangjiang Bridge,this paper studies the seismic performance of the single-tower asymmetric self-anchored suspension bridge through response spectrum,dynamic time history analysis and multi-point input considering the traveling wave effect,from the overall and local From the perspective of the seismic response sensitive area of the structure and the weak points of the structure,the scheme comparison,structural design and structural optimization of the structural bridge provide some reference conclusions.The main research content of this article is as follows:(1)By establishing the finite element model of the Zhaohua Bridge,the dynamic modes and boundary conditions of the monopole asymmetric self-anchored suspension bridge are analyzed by multi-Litz method to calculate the mode period and frequency of each mode mode and various modes.The influence of the change on the dynamic characteristics of the structure,for example,considering the influence of the pile-soiljunction effect on the dynamic characteristics of the structure,and deepening the understanding of the dynamic characteristics of the single-tower self-anchored suspension bridge,providing a preliminary reference for the subsequent seismic performance of the bridge.(2)Based on the site selection of appropriate seismic wave input,the average value is calculated for comparison.The dynamic time history method and response spectrum method are used to calculate the response of the structure under the action of elastic seismic wave.The reaction spectrum method and time history analysis method are used to observe the earthquake resistance.The advantages and disadvantages of the analysis are to understand the seismic response characteristics of the bridge type in the elastic stage.(3)Through the finite element simulation of traveling wave effect and other multipoint input influencing factors,the seismic response characteristics of the single tower self-anchored suspension bridge considering the traveling wave effect are analyzed,and compared with the consistent excitation input seismic wave,the seismic response results of the model under different seismic input methods are analyzed.Understand the influence of different seismic input methods on the seismic response of bridges,and consider the effects of traveling wave effect and multi-dimensional coherence on the structural response,and understand the degree of seismic response of seismic support to different key points and sections of the structure.