二郎山隧道出口端长约 79m,位于崩坡积地层段 ,施工中随着洞身的掘进 ,地表裂缝也在继续发展。由于施工中采用了超前大管棚加固地层 ,并用厚度足够的强有力的初期模注衬砌代替了原设计的初期锚喷支护 ,使得洞身施工顺利通过了崩坡积层 ,证明施工中采取的变更设计决策是十分正确的。 Erlangshan tunnel exit of about 79m, located in the collapse of the slope of the formation section, with the excavation of the tunnel construction, surface cracks are also continuing to develop. As a result of the construction of advanced pipe shed reinforcement stratum, and the thickness of the strong enough of the early lining of the original lining instead of the original design of the early bolt and spray support, making the tunnel construction successfully passed collapse collapse, to prove that the construction to take The design change decision is very correct.