The Analysis Of Buildings Above Tunnels Under Earthquake

As the large-scale development and utilization of underground space in the recent years,metro has become a major urban transportation vehicle.The interaction between the structure and the underground tunnel depengs on the interaction of the soil layers in the earthquake,which affects the seismic response of each other.In this paper,the influence of single tunnel,parallel double tunnels and intersecting tunnels on seismic response of the structure is studied by using the finite element method under the action of Tianjin wave and EL Centro wave.The main achievements are as follows:Based on the finite element analysis method,the three-dimensional model of soil-tunnel-structure interaction is established.For seismic response of single tunnel in layered site,the factors such as the tunnel depth,the horizontal distance between tunnel and structure,tunnel lining thickness are discussed.The study shows that under the action of Tianjin wave,the influence decreases with the increase of tunnel buried depth;Under the action of EL Centro wave,the influence increases with the increase of tunnel buried depth.With the increase of the distance between structure and tunnel,the influence becomes smaller.With the increase of the thickness of the tunnel lining,the influence of earthquake on the structure becomes larger.For seismic response of parallel double tunnels in layered site,the factors such as the tunnel space,the structure free vibration frequency,the comparison between single and double tunnels are discussed.Results shows when the distance increases,the influence increases first and then decreases.Under the action of Tianjin wave,the existence of the tunnel has amplification effect on the the 5-storey and 10-storey structure;the existence of the tunnel has a narrowing effect on the 15-storey structure.Under the action of EL Centro wave,the existence of the tunnel has amplification effect on the the 15-storey structure;the existence of the tunnel has a narrowing effect on the 5-storey and 10-storey structure.The influence of single tunnel on the seismic response of structure is greater than that of parallel double tunnel.Based on the advantage of three-dimensional model,the model of subway intersecting tunnel is established.And the factors such as intersecting tunnel angle and vertical distance are discussed.The result shows that the increase of cross tunnel angle will reduce the influence of seismic wave on the structure,and to the minimum at 90 degree.The larger the vertical distance of intersecting tunnel is,the greater the impact of earthquake on buildings is.