关键词: 双连拱, 公路隧道, 浅埋偏压, 动态监测, 数值模拟

Abstract: With the rapid development of the construction of highway tunnel in China, there are more and more multi-arched tunnels. Multi-arched 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. Number 2 tunnel in Chadao of Zhang-Shi highway is 188 m long, which is a double-arched tunnel. The grade of surrounding rock mainly is in grade IV or grade V. There are fragmentation, unsymmetrical pressure and lower imbedding phenomena in surrounding rock of tunnel’s entrance, which increases the difficulty of construction. By the approach of scene monitoring and numerical simulation, the displacement and distortion of surrounding rock with unsymmetrical pressure and lower imbedding are analyzed, after the tunnel is caved. As the result indicating, the outcomes of two analysis methods are accordant by and large. 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 supplied.

Key words: double-arch, tunnel of highway, lower imbedding and unsymmetrical pressure, dynamic monitoring, numerical simulation.