Abstract：
Entrance excavation is always the key link of tunnel construction, the smooth completion of tunnel entrance is the premise of normal tunnel construction. The surrounding rock is extremely weak and broken at tunnel entrance of Guojiachuan No.2 tunnel on Gao(Ping) - Ling (Chuan) Highway of Shanxi Province. After adopting advance pipe-roofing at the entrance, combined support of steel arch and a protective arch rib were adopted, the longitudinal connection of steel arches of primary support was reinforced, which proved to be efficient. The combined support can reduce the deformation of primary support at the entrance of the shallow tunnel in weak broken surrounding rocks, ensuring the stability of tunnel structure and the construction of tunnel entrance.
JIANG Tong-Hu-1,
Huo-San-Sheng-2,
Ye-Fei-1 etc
.Study on Entrance Excavation of a Tunnel in Shallow SoftFractured Surrounding Rock[J] MODERN TUNNELLING TECHNOLOGY, 2011,V48(3): 117-122
2011, Vol. 48 