关键词: 强渗漏地质段, 导孔成型, 反井钻孔, 白鹤滩水电站

Abstract: Anti-drilling method or one-step forming mucking shaft are usually used to excavate guide hole in deep-large shaft, but under strong leakage geological condition, the mucking cycle is easily interrupted due to the unable returning of drilling liquid, and drilling bit sticking accident brings about the failure to the excavation of guide hole. In view of this problem, firstly the improved sand-settling pipe is used to clean up the bottom hole sediment, then the geological-drilling machine with variable diameter casing is used to drill the hole continually, finally the technique of rotation of multi drilling equipment that use anti-drilling machine to expand the hole is applied to successfully excavate the guide hole. The successful application of this technology in No.4 exhaust shaft in Baihetan Hydropower Station shows its good quality and high efficiency, it can provide reference for shaft excavation by anti-drilling method in the area where the karst cave, cavity and water-conducting faults are widely spread.

Key words: strong leakage geology, guide hole forming, anti-drilling, Baihetan Hydropower Station