Abstract Many tunnels on the Lanzhou-Chongqing railway pass through soft rock with high ground stress, where large deformation problems are extremely prominent during tunnel construction. Using the construction of the Maoyushan tunnel as an example, this paper, based on the stress release concept and the reserved space method, reveals the deformation law and stress releasing ability of tunnels in soft rock with high ground stress. The results show that stress release is obtainable by the reserved space method during construction in soft rock with high ground stress, ensuring the safety of the primary lining. As for the flexible protective cover, it may be formed by 4φ22 mm lattice girder and 25 cm shotcrete with wire mesh, with the longitudinal distance between two steel frames being 0.75 m and the reserved space being 30~50 cm.
Abstract:
Many tunnels on the Lanzhou-Chongqing railway pass through soft rock with high ground stress, where large deformation problems are extremely prominent during tunnel construction. Using the construction of the Maoyushan tunnel as an example, this paper, based on the stress release concept and the reserved space method, reveals the deformation law and stress releasing ability of tunnels in soft rock with high ground stress. The results show that stress release is obtainable by the reserved space method during construction in soft rock with high ground stress, ensuring the safety of the primary lining. As for the flexible protective cover, it may be formed by 4φ22 mm lattice girder and 25 cm shotcrete with wire mesh, with the longitudinal distance between two steel frames being 0.75 m and the reserved space being 30~50 cm.
ZHANG ,
MEI 1,
Huang-Hong-Jian-2 etc
.Experimental Study on the Reserved Space Method for Tunnels
in Soft Rock with High Ground Stress
[J] MODERN TUNNELLING TECHNOLOGY, 2014,V51(1): 164-170