Seismic Vulnerability Analysis Of Aqueduct With Bent Structure

Aqueduct is an important hub project,which plays an important role in the national economy.Once damaged,it will bring great impact on people’s normal life.At present,many aqueducts in our country have not enough seismic capacity,so it is necessary to analyze the seismic performance of aqueducts.The seismic vulnerability analysis of the structure represented by the vulnerability curve can predict the failure probability of the structure under different damage levels,reveal the relationship between the failure probability of the structure and the earthquake intensity parameters,and provide the basis for the structural safety evaluation and the earthquake loss evaluation.Therefore,it is very necessary to carry out the vulnerability analysis of the aqueduct structure.Based on the characteristics of a typical aqueduct in northwest China,this paper analyzes the seismic vulnerability of aqueduct from its basic components.(1)Based on a large number of literatures,the development and research status of seismic vulnerability are summarized.This paper discusses the feasibility of seismic vulnerability analysis of aqueduct structure.(2)This paper introduces the process of theoretical seismic vulnerability analysis based on numerical simulation,compares the advantages and disadvantages of damage transcendence statistical method and direct regression fitting method,and establishes the vulnerability curve of basic components of aqueduct by direct regression fitting method.Based on the research of damage state and damage index at home and abroad,the displacement ductility ratio is used as the damage index of bent frame,the relative deformation is used as the damage index of rubber bearing,and the damage limit is quantified.(3)The three-dimensional model of aqueduct is established by the finite element software,the effect of water body is simulated by the additional mass,and the foundation is simulated by the massless foundation.The rubber bearing and bent frame of the basic components are introduced in detail.In this paper,the peak acceleration of the ground is used as the index of ground motion intensity for dynamic time history analysis,and the uncertainty of ground motion is considered by stratified sampling method,and the uncertainty of aqueduct structural parameters is considered by Latin hypercube sampling method.(4)Based on the time history analysis data,the linear regression analysis of the seismic parameters and seismic demand of the components is carried out by using the least square method,and then the vulnerability curve of the basic components of the aqueduct is established,and the longitudinal and transverse vulnerability curves of the components are compared and analyzed.(5)Based on the reliability theory,the aqueduct is regarded as a series structure and a parallel structure,and the seismic vulnerability curve of aqueduct system is drawn by the traditional limit method.(6)The Copula function method is introduced to separate the correlation between seismic requirements of aqueduct components and the edge distribution function of components.The joint probability distribution function between seismic requirements of components is established and the vulnerability curve of aqueduct system is obtained.The calculation results are compared with the upper and lower bounds of aqueduct system vulnerability obtained by boundary method.The research results show that the vulnerability curve of Aqueduct Based on Copula function is more accurate and efficient,and can describe the vulnerability of aqueduct system better.