TECHNIQUES FOR TREATMENT OF DISASTERS IN TIESHAN TUNNEL

The Tieshan Tunnel of Ba Peng highway is Situated in Dachuan city of Sichuan province with a total length of 2 099 m at 66° northwest of the Tieshan valley. Due to several influence factors, such as the coal mining subsidence, groundwater, weak surrounding rock, etc, disasters occurred in the K140+527～+608 section. The disasters in this section included the crack, broken bench cut and rock mass falling of the secondary lining, the bending and shearing break of the reinforcement, and the cracking and leakage of side wall nearby wate channel. These disasters endangered the safety running, the communication was interrupted, and the repairing works were put forward. The repairing methods are introduced mainly in this paper as follows: after reinforcing by grouting for the surrounding rock of the tunnel and its mining subsidence region, the secondary lining and its inverted arch,the pavement in serious disaster sections were demolished and the reinforced concrete structures were reconstructed again; in the other hand, the reinforced concrete casing linings were reconstructed for consolidation in general disaster sections.