Research and Application of Shaft Excavation by Deep Hole One-Time Blasting Technology

Abstract

In the construction of subway, tunnel, mining and other underground projects, in order to speed up the construction progress, it is often necessary to excavate a shaft first and then dig at both ends of tunnel at the same time. The shaft excavation is a difficult problem in underground engineering. At present, the shaft excavation construction mainly adopts upward construction method and downward construction method, which are characterized by high labor intensity, high risk coefficient and slow construction speed. In order to realize the efficient excavation of vertical shafts, this paper presents a technology of deep hole one-time blasting into wells. Based on theoretical analysis and practical shaft engineering, the blasting parameters of the deep hole one-time blasting technology are given, such as hole diameter, spacing, layout, charge structure and blasting sequence of each hole, and the technical scheme is formed finally. The technology is applied in a shaft excavation construction in Changping District, Beijing of China and good results are obtained, which proves that the technique is feasible.