关键词: 泥水盾构, 提前到达, 越海取水隧洞, 爆破开挖, 空推, 盾构井

Abstract: In the construction of No. 1 water conveyance tunnel of Taishan Nuclear Power Station, the shield machine, according to the original plan, was to stop boring at the position 140.6m away from the arriving shaft, with the remaining tunnel section to be excavated by drill+blast method from the arriving shaft. However, due to the legging of the shaft sinking, the shield machine has to continue boring to the position 5m away from the arriving shaft, so as to keep the overall construction schedule of the project. In the paper, the measures taken before shield arriving are analyzed, the design of the blasting parameters for the last 5mlong tunnel section is described and the key technologies and control points for the arrival of the shield machine are summarized. Conclusions drawn are as follows: 1) The solution that the shield machine stops boring at the position 5m away from the arriving shaft and then the cutter head of the shield machine is withdrawn 0.7m away form the tunnel face is feasible, which not only guarantees the construction schedule of the project, but also guarantees the effective protection of the shield machine; 2) In the arriving section, the shield machine advances under small thrust force and low rotation speed; the remaining 5mlong tunnel section is excavated by drill+blast method and supported by rock bolting, shotcreting and secondary segment lining. In this way, the successful arrival of the shield machine is guaranteed and the uplifting and dislocation of the segments and the water seepage from the segment joints are brought under effective control. 

Key words: slurry shield, arrival, seacrossing water conveyance tunnel, drill+blast, advance without load, vertical shaft