浅埋大跨度连拱隧道地震反应分析

Earthquake response of large span and double-arch shallow tunnel

在动态有限元理论的基础上,对浅埋大跨度连拱隧道进行地震反应分析。通过工程分析,求解浅埋大跨度连拱隧道地震反应的结构内力,与单拱隧道内力进行对比分析。研究结果表明:连拱隧道中隔墙上部在地震力作用下最大位移、速度、加速度响应值分别为0.107 m,0.580 m/s和4.297 m/s2,比同烈度下单拱隧道的地震反应值大得多;浅埋连拱隧道洞顶以及中隔墙上部是抗震的薄弱环节,也是拉应力集中区;隧道边墙是压应力集中区;与单拱隧道相比,连拱隧道的抗震能力较弱。

Based on the dynamic finite element method, the dynamic mechanical model of large span and double-arch shallow tunnel for practical use was persented. Numerical calculations were performed, numerical results were compared with those of single arch tunnel, and suggestions were put forward to reinforce large span and double-arch shallow tunnel subjected to earthquake loads. From the numerical results, it can be found that the maximum displacement, velocity and acceleration for the central wall are 0. 107 m, 0. 580 m/s and 4. 297 m/s^2 , respectively, and that the results are greater than those of the single arch tunnel. Therefore, the conclusion can be drawn that the weak locations are vault and central wall under the earthquake loads where the stresses of press and pull are greater, and that resistance behavior of single arch tunnel is better than that of double-arch tunnel.