山岭隧道洞口段衬砌刚度对其抗震性能的影响

利用ABAQUS有限元模拟软件建立V级围岩条件下山岭隧道洞口段的地震响应数值模拟三维模型,对比研究其在不同衬砌刚度时的抗震响应情况,从而得到衬砌刚度对其抗震性能影响的规律.衬砌刚度取用20 GPa、30 GPa、40 GPa、50 GPa四种不同工况,在模型底部施加水平方向的地震荷载.通过研究发现：当衬砌刚度为30 GPa时能起到较好的抗震效果,且结构强度有较大富余量;刚度为20 GPa时结构偏“柔”致使位移量过大,不利于结构的抗震;当刚度为40 GPa甚至更大时,结构的受力和地震过程中的峰值加速度明显增大,且位移量减小不明显,对提高抗震性能作用不大.

On the Influence of the Lining Stiffness on Its Seismic Performance of a Tunnel at the Portal Section

With the help of the finite element simulation software of ABAQUS, a 3-D numerical simulation model is established to analyze the seismic response of the portal section of a mountainous tunnel in V-level surrounding rock in the paper,with its seismic responses at different lining stiffness studied and compared, upon the basis of which the law of the influence of the lining stiffness on the seismic performance is obtained. During the study, the lining stiffness is respectively set under four different construction conditions： 20 GPa,30 GPa, 40 GPa and 50 GPa,with a seismic load in the horizontal direction is exerted on the bottom of the model. The research shows that the lining stiffness of 30 GPa may result in better seismic performance and the strength of the lined structure still has relatively more than needed. The lined structure tends to be softer at the stiffness of 20 GPa, with the displacement Of the lined structure being too large, which will do harm to the seismic performance of the lined structure. When the ling stiffness is set at 40 GPa or larger, the inner forces of the lined structure and the peak acceleration during the earthquake are obviously increased. Moreover, the displacements are decreased insignificantly and little effect to improve the seismic performance of the lined structure of the tunnel is achieved.