Abstract:

Yinmahe surge shaft in No. 4 bid section of Songhuajiang River Water Conveyance Project is a cylindrical vertical shaft with 50 m depth and 20 m diameter. The shaft is located in tuffaceous sandstone. Due to the steep landforms and complex conditions at the ground surface around the shaft, it is very difficult to establish the access roads and construction sites for the shaft, and it is very difficult to mobilize the heavyduty equipment to the site. After extensive literature survey and study, raise boring method is adopted for the shaft. In the paper, the technologies for the raise boring technologies, including the blasting zone division, blasting scheme and key blasting techniques, are presented. In the end, the shaft has been completed successfully.

Key words: water supply project, surge shaft, superlarge diameter, super depth, raise boring