BLASTING, Volume. 42, Issue 1, 26(2025)
Experimental Study on Open-pit Blast Effects with Various Decoupled Charge Mediums in High and Cold Regions
During drilling and blasting of open-pit mining in high and cold regions, water inrush or freezing often occurs on the borehole inside. This phenomenon creates a decoupled charge structure with water and ice, affecting the blasting effect and the rock-breaking mechanism under decoupled conditions. To determine the geometric parameters of the blasting crater and analyze the blasting effect under three types of decoupling medium in the high-cold area, a series of tests were conducted on the blasting effects of different decoupling charges in the Karma open-pit mining in Tibet. Based on the Livingston curve fitting results, the blasting parameters were optimized and applied to on-site engineering blasting. The results indicated significant differences between the visible volumes of the blasting crater and the crushed funnel at burial depths of 1.09~1.49 m. However, these volumes resembled burial depths of 1.49~1.69 m. Compared to the air-deck decoupling, the peak particle velocities under water and ice decoupling were reduced by 25.33% and 11.24%, respectively. The critical charge depths varied among the three decoupling materials, with water decoupling having the most significant critical depth, ice decoupling charge, and air-deck decoupling having the shallowest. The charge weights required for water and ice decoupling and ice decoupling were 18.9% less than those for air-deck decoupling. In multi-hole bench blasting, the explosive factor for water and ice decoupling was reduced by 18.2% compared to air-deck decoupling, and the rate of large fragments decreased from 8.9% to 4.3%. This indicated that water and ice decoupling charges made the energy distribution of explosives more uniform.
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FEI Hong-lu, JING Guang-jie, ZHEN Shuai, JIA Hong-yu. Experimental Study on Open-pit Blast Effects with Various Decoupled Charge Mediums in High and Cold Regions[J]. BLASTING, 2025, 42(1): 26
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Received: Apr. 26, 2024
Accepted: Mar. 21, 2025
Published Online: Mar. 21, 2025
The Author Email: Guang-jie JING (m13468364850@163.com)