Abstract:

The serious deformation of soft rock is one of the main research topics in the field of underground works. Factors such as the complex geological conditions, the uncertainty of the surrounding rock, the complexity of the rock deformation mechanism, the construction method and the technologies used may affect the stability of the surrounding rock of the tunnel. Xingyuan tunnel, which is located in the high altitude area in Northeast China, passes through carbonaceous mudstone under unsymmetrical pressure. In the paper, the causes for the serious deformation of Xingyuan tunnel are analyzed, the deformation control standard for the surrounding rock is determined, and a series of countermeasures including using innovative excavation equipment and installing long footlocking anchorage are taken. The paper can provide reference for other similar tunnels in the future.

Key words: very cold region, carbonaceous mudstone, large deformation, unsymmetrical pressure, soft rock, high ground stress