浅埋偏压连拱隧道洞口段数值模拟与监测研究

Research on Portal Section Numerical Simulation and Monitoring of Shallow Unsymmetry Pressure Double-arch Tunnel

公路连拱隧道一般应用于中短隧道工程,常常存在地质条件较差、浅埋偏压等问题.栎斜隧道是宁波象山港公路中的一座双向四车道连拱隧道,出口段存在明显的偏压现象,围岩破碎,地质条件复杂,给施工带来一定的难度.本文采用现场监控量测和数值模拟两种手段,在监测断面进行周边收敛位移、拱顶下沉和地表沉降监测,并与数值模拟结果对比分析.监控量测和数值模拟结果一致,表明采用数值模拟的可行性,弥补了现场监控量测预见性较差的缺陷.

Double-arch tunnel is usually used in the construction of middle and short length tunnels, and there usually appears the problems of unsymmetrical pressure and unfavorable geological conditions. Lixie Tunnel is locted in Ningbo, China. There are complex geologic conditions, broken surrounding rock and obvious unsymmetrical pressure on Xiangshangang Port bridge road with a multi-arch tunnel of bidirectional four roadways. It is very difficuct to construct. By the approach of scene monitoring and numerical simulation, the displacement and distortion of surrounding rock with unsymmetrical pressure and lower imbedding are analyzed. The comparative results show that the monitoring measurement and numerical simulated results are the same. So the numerical simulation method is feasible in analysis of tunnel construction. At the same time, the gap of monitoring method whose prediction is poor is also made up.