@article{PENG2025, 
author = {Song-lin PENG and Wei DONG and Qian DONG and Zhao YANG and Fu-quan JI and Ang CAO},
title = {Experimental Study on Blasting Using Short Burn-cut Hole Combined with Wedging Shot Scheme for Hard Rock Circular Water Conveyance Tunnel},
year = {2025},
journal = {BLASTING},
volume = {42},
number = {4},
pages = {89-96},
keywords = {water conveyance tunnels, composite cut blasting, blasting parameters, circular tunnels},
url = {https://www.sciopen.com/article/10.3963/j.issn.1001-487X.2025.04.010},
doi = {10.3963/j.issn.1001-487X.2025.04.010},
abstract = {The traditional wedge-shaped blasting scheme is restricted by the limited working space of construction equipment in small to medium-sized section tunnels, which would result in a large angle between the wedge-shaped blasting hole and the tunnel face. A greater confinement of the rock in the blasting area may lead to a short cycle advance, a low utilization rate of drill holes, and high explosive consumption, among other issues. In this paper, the advantages and disadvantages of the wedging shot and the burn cut were compared based on theoretical analysis and formula derivation. And then, the parameters of the burn-cut hole were further calculated. Finally, a short straight hole and wedge-shaped composite blasting scheme was designed, and a field test was conducted in a hard rock circular power tunnel of a hydropower hub project. The results indicate that the high-strain-rate effect should be considered when determining the tensile strength of rock to ensure the rationality of theoretical calculation parameters, particularly in determining the spacing between the charge hole and the empty hole in trench blasting parameters. Compared with the original scheme, the single-cycle blasting footage increases from 1.7~1.8 m to 2.0~2.1 m, the utilization rate of the blast hole increases from 73.91%~78.26% to 86.96%~91.30%, the single-cycle footage and the utilization rate of the blast hole are improved, and the unit consumption of explosives is almost the same as that of the two schemes. Additionally, the unit consumption of the detonator is reduced by approximately 0.4 rounds/m3, and the economic benefits of its application are greater. It has fewer residual eyes on the tunnel face and higher fragmentation by adopting a combination of short burn-cut holes and wedging shots, which is convenient for subsequent slag removal and the next cycle of drilling operations.}
}