Study On Seismic Performance Of Subway Tunnel Based On Numerical Analysis

In many cities, subway is an important way to solve traffic congestion, meanwhile, it is an important component of public transportation system. Although the subway tunnel surrounding soil can provide a degree of protection to improve the safety of underground tunnel, the structure will deform with the soil and the weaknesses will severely damage when great earthquake occurs. In order to ensure this vital lifeline subway reliability, and to strengthen the capacity to withstand earthquake, it has a certain theoretical significance and practical value to carry out the seismic performance of subway tunnel. Based on the Project background of Shenyang Metro Line "Style Road Station-Industrial Exhibition Hall station", we analyzed simulated seismic performance of the subway tunnel using ABAQUS finite element analysis software.Based on numerical analysis theory and the theory of ABAQUS application, we determined the basic conditions from the three aspects that integration algorithm, constitutive model and seismic waves. On this basis, we treat the subway tunnel and surrounding soil as a whole to establish the model and imposed horizontal seismic wave simulation, so as to carry out seismic response analysis on the subway tunnel structure. We focuses on the analysis of the subway tunnel under horizontal seismic loads in lining feature points and overall dynamic response. By comparing and analyzing their displacement-time curve, stress-time curve and velocity-time curve, we got characteristic point’s weak position of the subway tunnel lining under the horizontal seismic loads. Combined with literature examples of destruction forms, the tunnel damage modes and the simulation results, we analyzed the strain of feature points, after that, we summed up failure modes in a subway tunnel under horizontal seismic load,, then we showed that the direction of the camber line of the subway tunnel± 45° and±135° reciprocating movement, resulting in a subway tunnel fatigue damage to the weak position.Based the effecting factors on the seismic response of subway tunnel, we analyzed the seismic performance of the subway tunnel structure for this project from three aspects. These aspects are earthquake environmental factors, environmental factors and subway tunnel geological structure factors. By calculating the displacement of subway tunnel, it does not exceed the limit of seismic displacement specification. So we concluded that, project’s seismic performance is fine. Based on the results of seismic performance and for the displacement and velocity weak position of subway tunnel feature point, we proposed seismic measures and hope it to be helpful and reference for scholars in the field for future work in the study.