Abstract:

The rockbolted crane girder of Xiangjiaba Hydropower Station has poor geologic conditions, complex design profile and high quality requirements. Blast forming technology is established and applied for the first time in the construction of the rockbolted crane girder of the hydropower station. In this paper, the authors present the construction sequence, construction method, controlled blasting design, construction technology and blasting vibration observation in detail. With the above measures and scientific management, the excavation quality of the rockbolted crane girder is guaranteed, with the halfhole ratio of the smooth blasting reaching 100% and the average overbreak of the rock bench being only 2.9cm.