隧道建设对紧邻高架桥影响的三维数值分析

3D numerical analysis of influence of tunnel construction on neighboring viaduct

运用MSC.Marc三维有限元分析软件,模拟了隧道分区分层动态施工和运营期行车荷载对紧邻高架桥的影响,重点分析了扩大基础基底反力增量、基底中心沉降、扩大基础倾斜和基坑侧向位移的发展规律。数值研究结果表明,(1)隧道底面开挖标高高于扩大基础基底标高,导致隧道施工过程扩大基础基底卸载反弹;(2)作用在6号墩扩大基础上方一侧的规划道路行车荷载,导致该扩大基础倾斜,基底中心加载沉降;(3)隧道建设诱发扩大基础最大总倾斜为0.6‰;(4)隧道运营期行车荷载导致基底中心最大沉降为3.7 mm。分析该隧道工程地下水渗流模拟结果认为,该隧道建设不会危及该紧邻高架桥的安全。

Influence on the neighboring viaduct pier＇s extending footings was numerically studied by using MSC.Marc 3-D software, which induced by the tunnel staged construction and the traffic loading during the working period. The incremental developments of these extending footings＇ stresses, settlements and inclinations were analysised, as well as the retaining structure＇s lateral displacements. And the obtained results indicate that： （1） These extending footing＇s unloading during the construction is due to that the tunnel bottom level is higher than these extending footing＇s. （2） The No. 6 extending footing＇s inclination and settlement is mainly induced by the planning traffic loading which directly acting on its one top side. （3） The extending footing＇s maximum inclination is 0.000 6. （4） The extending footing＇s maximum settlement induced by the tunnel traffic loading is 3.7 mm. Combined with the obtained results of the groundwater seepage, it deems that the tunnel construction and working period does not endanger the viaduct＇s safety theoretically.