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Innovative approach based on roof cutting by energy-gathering blasting for protecting roadways in coal mines
•Innovative approach (CREGBPR) is based on the directional blasting for protecting roadways.•CREGBPR optimizes the roof structure by utilizing the rock nature.•CREGBPR improves the evolution and distribution of the abutment stress.•Field test verified the feasibility and effectiveness of CREGBPR. As...
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Published in: | Tunnelling and underground space technology 2020-05, Vol.99, p.103387, Article 103387 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | •Innovative approach (CREGBPR) is based on the directional blasting for protecting roadways.•CREGBPR optimizes the roof structure by utilizing the rock nature.•CREGBPR improves the evolution and distribution of the abutment stress.•Field test verified the feasibility and effectiveness of CREGBPR.
As underground mining progresses to deeper levels, roadway control has become a significant issue in the development of modern mines with characteristics of a high yield and high efficiency. To protect deep roadways from dynamic disasters, an innovative approach based on cutting the roof by energy-gathering blasting for protecting the roadway (CREGBPR) was studied. First, the key technique of energy-gathering blasting was introduced. CREGBPR was developed by using the blasting technique and to directionally cut the roof above the roadway following a specific design. Theoretical analysis, numerical simulation, and field tests were combined to analyze the roadway control mechanism of CREGBPR. Compared with the original approach, the CREGBPR approach uses the broken and expanded rock mass to support the fractured structure of the main roof, reducing the impact on the retained roadway. Furthermore, the improvement in the structure eliminates the roof overhanging the roadway coal pillar. The pillars can serve as integrated supporting bodies that bear the abutment stress. Meanwhile, the stress environment is improved significantly by the roof cutting effect; the stress evolution includes new areas in which the stress distributes more uniformly. As a result, these independent effects induced by CREGBPR are integrated to protect the roadway effectively. A field test was conducted to verify the effectiveness of CREGBPR. The roadway convergence and roof weighting were significantly reduced. The research results prove that the CREGBPR approach is feasible for engineering applications and can protect roadways in deep mines. |
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ISSN: | 0886-7798 1878-4364 |
DOI: | 10.1016/j.tust.2020.103387 |