| The integrated structure system of large transportation hub and high-speed rail station has become a new metropolis integrated transpotation system.Although the integratd structure system provides a great handling capacity of passangers,the high-speed passing train may cause a terrible impact on the facility usage and people’s work and rest.The demand of vibration attenuration cannot be satisfied by only isoalting the vibration source,additional isolation techniques should be made at the structure basement.Spring isolation is the most efficient technique and is suggested to set between the structure basement and the top slab of rail station.It forms a three dimensional integrated structure system of large transportation hub and high-speed rail station with partial isolation.Partial isolation changes the vibration characteristics and interal force of large transportation hub structure,resulting in in a potental seismic risk.This thesis investigates the vibration characteristics,deformation features,damage pattern and soil-structure interaction of the partially isolated structures under three dimensional earthquakes.Based on the damage characteristics of the large transportation hub,this thesis also investigates the efficient dynamic analysis method for larger and complex nonlinear structure.The main research works are outlined as follows:First,the Euler-Bernoulli beam with flexbile constraints is employed to deduce the vertical vibration equation.The mode curvature is ultilized to analyze the characteristics of vibration and deformation.Subquently,this study establishes the finite element model of a large transportation hub system,analyze its natural frequency,vibration modes,and effective modal mass,reveals the influence of partial isolation on the dynamic characteristic of the large transportation hub.Subquently,analyze the impact of partial isolation on the seismic performanc of the large transportation hub through acceleration response,structural deformation,ductility,and hysteresis behavior.Second,this study establishes the finite element model of partially isolated large transportation hub-ground coupling system,employs three dimensional artificial boundary condition and effective seismic input method to simulate ground motion,and verifies its accuracy.The acceleration response spectrums of separate soil layer locations on the spreading path of ground motion are investigated,in order to analyze the influence of partial isolation on ground motion under different soil types.Subquently,analyze the impact of partial isolation on the seismic performance of the large transportation hub under different soil types,through the simulation results of acceleration response,structural deformation,and damage distribution.Third,this study proposes an adaptive dynamic elasto-plastic analysis method according to the initially elastic state and plastic damage state.The numerical procedures of adaptive dynamic elasto-plastic analysis are deduced.Subquently,the topology method and mode truncation criterion of linear substructrues are established.The influence of substructure interface coupling on the mode truncation errors is investigated.Subquently,this study proposes spectrum analysis method for the duration of damage settled state,investigates the characteristics of the damage settled state,reveals the ratio of duration of damage settled state to the ground motion duration.Based on this investigation,the model reduction method of nonlinear substructrues during the damage settled state is proposed.Finally,this study develops the finite element software for the proposed adaptive elasto-plastic analysis method.The adaptive substructure modeling technique is implemented by conducting the modeling of substructure abstract layer.Subquently,the adaptive dynamic elasto-plastic analysis is implemented by conducting the finite element reanalysis triggered by damage state.Subquently,the accuracy and efficiency of the proposed simulation method are validated by the developed software and test structures. |
