Stochastic Dynamic Response And Seismic Reliability Analysis Of Subway Station Structures Based On Probability Density Evolution Method

The birth of the subway has solved the complex problems of urban transportation,and it is a convenient,large volume of transportation,using clean energy rail transit.However,since the underground structure started relatively late compared with the above-ground structure,there are few relevant normative data,so for a long time,people have little understanding of the damage mechanism of the underground structure of subway station.In recent decades,underground structures have suffered frequent earthquakes and many have been severely damaged,exposing many problems.Since then,seismologists at home and abroad began to re-examine the seismic problems of underground structures such as subway stations.Several severe earthquakes in recent years have given people a wake-up call.People have realized that the underground structure will not suffer less damage in the earthquake than the surrounding rock and soil because of the protective effect,and sometimes the damage will be far more than the above-ground structure.However,in the current traffic track seismic design code,the regulations on the subway station structure are not as clear as the above ground structure,and there is no perfect seismic analysis method for the underground structure.Therefore,the seismic performance analysis of underground structure of subway station is urgently needed.This paper is based on the model of Dakai subway station which experienced severe earthquake damage in history.Geotechnical using generalized plasticity model around subway station,concrete structure is adopted and plastic damage model,the generalized plasticity model to simulate the concrete surfaces in the contact area between the structure and geotechnical,select a series of in conformity with the standard spectrum of ground motion as a ground motion input,was carried out by the subway station on the nonlinear dynamic response analysis of underground structures.The specific work of this paper is as follows(1)This paper briefly introduces the research progress of underground structure,random function-spectrum representation and probability density evolution methods of subway stations,and analyzes the shortcomings of current research on underground structure of subway stations.Considering the randomness of ground motion,the reliability of underground structure of subway station is obtained based on probability density evolution theory and random ground motion model.(2)Based on random function-spectral representation method and the improved power spectral density model,according to the urban rail transit structure seismic design specification to determine the parameter selection of the model,established the non-stationary ground motion time history evolution of power spectrum model,greatly reduced the number of random function,with only a random function to express the original non gaussian process.A group of non-stationary ground motions consistent with the standard spectrum is obtained by iterative correction,which lays a foundation for random seismic response and dynamic reliability calculation of underground structure of subway station.Compared with other methods,the computation of this method is greatly reduced.(3)Using the group GEODYNA self-developed finite element calculation software to analyze the dynamic characteristics,combining with the research results of experts and scholars at home and abroad,before selecting indications interlayer corner and roof slab between the relative vertical displacement,the damage area of the three representative analysis indicators,based on the probability density evolution theory and equivalent extreme value thought,analysis of the subway station underground structure under random seismic excitation response problem and calculated the dynamic reliability of the various indicators,random seismic response analysis for subway station,underground structure provides a new way.(4)Finally,this paper summarizes the research work done in this paper,points out the shortcomings and areas for improvement,and points out areas for further research.