Reaserch On Response Of Subway Tunnel-soil-RC Frame Structure Under Earthquake

Near subway stations,most of buildings have already been built.With the rapid development and utilization of underground space,more and more attention has been paid to the earthquake resistance of subway tunnel-soil-superstructure in the case of earthquake.Its significance lies in ensuring the normal use of subway tunnel-soil-superstructure when earthquake occurs.On the basis of the existing research theories at home and abroad,this paper mainly completed the following research aspects.(1)It analyzed the influence of changing RC frame structure position on subway tunnel-soil-RC frame structure.The results showed that the larger the horizontal distance between RC frame structure and the middle points of two tunnels was,the smaller the storey displacement of RC frame structure was and the smaller the increase amplitude of the tunnel acceleration was.The amplification coefficient of soil acceleration increased with the distance of RC frame structure from observation point.(2)From the aspect of different soil stiffness,the smaller the soil stiffness was,the larger the storey displacement of RC frame structure was and the larger the increase amplitude of the tunnel acceleration was.Meanwhile,the amplification coefficient of soil acceleration increased as well.(3)From point of view of the number of tunnels,in the case of frequent earthquake waves,the more the number of tunnels was,the greater the storey displacement of the superstructure was.In addition,the stress on the core area of side columns and the amplification coefficient of soil acceleration also increased.In the case of less earthquake action,the number change of tunnels has little effect on the superstructure and the dynamics of the tunnel itself.(4)From the prospective of different burial depth of tunnels,the dynamic response of RC frame structure decreased with the increase of tunnel burial depth.What’s more,the amplification coefficient of tunnel acceleration and the relative horizontal displacement of tunnel roof and floor also decreased.(5)From the prospective of the alignment change of the four tunnels,when the four tunnels were closely aligned,the structure had strong response.The amplification coefficient amplitude of upper tunnel decreased with the increase of its acceleration amplification coefficient.The acceleration amplification coefficient of soil increased with the increase of the acceleration amplification coefficient of lower tunnel.(6)This paper used Pushover to analyzed that if the RC frame frame structure had too many storeys,it would more likely that the plastic hinge would eventually appear and the damage would be aggravated.The plastic hinge distribution of RC frame structure will increase with the increase of the number of tunnels,and the more serious the damage is.