The Simulation Of The Seismic Dynamic Interaction Between Urban Complex Sites And Building(s)

In recent years,with the increasing tension of urban land and the rapid development of rail transit in China,the situation that building(s)are built in complex sites becomes more and more common.However,a large number of buildings have not been tested by strong earthquakes,and there is a lack of corresponding assessment of the damage areas and locations that may occur under complex site conditions.Therefore,more and more attention has been paid to the impact of earthquake on urban building(s)and surrounding complex local sites.Local sites include natural sites with special topography and inhomogeneous geology as well as artificial sites such as underground stations,lined tunnels and comprehensive pipeline galleries.Because seismic waves propagate along the boundary of local sites,the superposition of infrasound and incident waves makes the seismic response of the interaction between urban buildings and local sites more complex.At present,the interaction of earthquake dynamic magnification between urban buildings and their near-field sites has been confirmed by more and more earthquake damage investigation and scientific research.Therefore,it is necessary to study the complex site-city interaction(SCI effect)under earthquake action,and to serve the pre-earthquake disaster prevention and mitigation planning and rapid post-earthquake rescue.It is of great significance to mitigate the risk of urban earthquake disasters.In this paper,the indirect boundary element method and the viscoelastic boundary wave finite element method are used to simulate the seismic interaction of tunneladjacent buildings,layered sedimentary valleys-buildings.Firstly,the indirect boundary element method is used to calculate the seismic dynamic interaction of tunnel-adjacent buildings.Then the harmonic response analysis and transient analysis of ANSYS finite element software is used to study the seismic dynamic interaction between layered valleys and buildings.The results show that:(1)There is a distinct interaction between the buildings and the adjacent subway tunnels,the whole dynamic response depends on the spatial relationship between tunnels and buildings,the buried depth of tunnel,the frequency and the angle of incident wave,etc.The isolation effect is obvious when the rigid lining tunnel is just below the building;the displacement of the ground surface and the top of the building amplify obviously when the tunnel is located on the left side of the building,the maximum displacement can be about 40%.What is more,the stress of the lined tunnel also amplifies when the tunnel is located on the left side of the building,the maximum is about 43%.In reality,it is necessary to adjust the seismic fortification levels of lining tunnels and buildings which along the existing subways according to the spatial location of lined tunnels and buildings.(2)The number of buildings,the spacing of buildings and the existence of high-rise buildings all have certain influence on the seismic dynamic interaction between stratified sedimentary valleys and urban buildings.The existence of building clusters makes the coherence effect between sedimentary Valley and building clusters,which easily leads to the spatial redistribution of displacement response amplitudes of basins.On the whole,the seismic response of sedimentary basins will be weakened,with a maximum reduction of about 50%.The influence of the basin on the buildings is complex,and at low frequencies,the seismic displacement response of the buildings in the center of the basin is large.In practical engineering,building groups should be avoided as far as possible near the center of the basin.