Research on key construction technologies of frozen shaft in ultra deep and thick alluvium

According to frozen drilling and support construction technology problem of main shaft in Wanfu Mine with 754.8 m ultra deep and thick alluvium, this pa per studied and practiced the key techniques of excavation and support in Wanfu Mine freezing sinking engineering, including frozen wall stability, frozen soil tunneling t echnology, high performance concrete wall support. We used two methods to determine the time of excavation by calculating the pace of frozen soil development and m easuring temperature of temperature-measuring hole. According to the design thickness and average temperature of frozen wall, we analyzed the frozen wall deformati on. Based on the results, the safe height of section and exposure time were determined for excavation alluvium. The umbrella drilling rig with bolt head, twist drill rod a nd Y shaped drill were used to drill borehole in froz en soil. Inorder to solve the frozen soil drilling and blasting construction problems, This paper select the low temper ature and water gel explosives, and preserved heat for explosive. A series of high performance concrete production and transport techniques were adopted to guarante e the quality of high performance concrete lining, such as gravel wash screen means, underground mine concrete transport system and underground mine concrete fixe d points ash, especially steel fiber reinforced concrete lining in the deep freeze alluvium shaft support.