| 2. | This paper expounds the harms of the tunnel collapse , analyzes on the reasons of the collapse that occurs in the excavation and construction of the soft wall rock , and advances some measures that should be adopted in the construction of soft wall rock from aspects of the excavation , support , improvement , and reinforcement , etc 阐述了隧道坍塌的危害性,分析了在软弱围岩中开挖及施工中坍塌的原因,从开挖、支护、改良、加固等方面,提出了软弱围岩施工中应采取的措施和方法。 |