A Study on Cut Blasting with Large Diameter Charges in Hard Rock Roadways

To overcome the problems of poor cutting effects in hard rock roadways, a cut blasting technique with large diameter charges was developed; that is, the cut holes employ 50 mm diameter blast holes and 45 mm diameter explosive sticks, while the other holes adopt 42 mm diameter blast holes and 35 mm d...

Full description

Saved in:
Bibliographic Details
Published in:Advances in civil engineering 2020, Vol.2020 (2020), p.1-18
Main Authors: Li, Chengjie, Wang, MengXiang, Xu, Ying, Zong, Qi, Wang, Haibo, Cheng, Bing, Zheng, Qiangqiang
Format: Article
Language:English
Subjects:
Blast holes
Blasting (explosive)
Civil engineering
Computer simulation
Cutting
Damage
Explosions
Field tests
Roads
Roads & highways
Rock masses
Stress distribution
Stress waves
Wedges
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:To overcome the problems of poor cutting effects in hard rock roadways, a cut blasting technique with large diameter charges was developed; that is, the cut holes employ 50 mm diameter blast holes and 45 mm diameter explosive sticks, while the other holes adopt 42 mm diameter blast holes and 35 mm diameter explosive sticks. First, the effect of charge diameter on damage range and cut cavity formation was analyzed. Next, simulation of wedge cut for different charge diameters was conducted to reveal the stress wave developments and compare the stress field intensities. Finally, field tests were conducted to verify the viability of this technique. The results indicate that large diameter charges can increase the damage range around cut holes to improve the fragmentation degree of the rock mass in the cut cavity and significantly enhance the cavity formation power to better expel the rock mass fragments. The stress wave evolution of wedge cut was visualized using numerical simulations, which confirmed that the use of large diameter charges in cut holes increases the stress field intensity in the cut cavity and hence increases the damage degree of the rock mass. In this study, the use of a large diameter charge for cut blasting increased the average footage by 0.30 m, and the average utilization rate of blast holes increased by 12.5%. Therefore, the cutting effects in hard rock roadways can be improved by using large diameter charges, which increase the blasting footage and the utilization rate of blast holes.
ISSN:1687-8086
1687-8094
DOI:10.1155/2020/8873412