(接2018年12期96页)1.7剪力破坏(Shear fracturing along fissures and strain wave-generated cracks)[14]即在天然裂隙及震波产生裂隙间之剪力破坏。每一岩体飞离时相互间会有一剪力破坏,原因为岩块彼此间抛掷时的不同速度,造成额外...(接2018年12期96页)1.7剪力破坏(Shear fracturing along fissures and strain wave-generated cracks)[14]即在天然裂隙及震波产生裂隙间之剪力破坏。每一岩体飞离时相互间会有一剪力破坏,原因为岩块彼此间抛掷时的不同速度,造成额外的破碎,当同一排中炮孔齐发时此垂直剪力破碎最小,如图7所示。1.8岩块间彼此碰撞的破碎(Fracturing by in-flight collisions)[8]在坑道爆炸中较露天阶段显著,原因为坑道先炸向拔心所提供的空间再转向九十度(90°)排向隧道面,互撞速度为高,飞奔的岩块彼此碰撞造成额外之破碎。展开更多
Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Contro...Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving technique and support resistance has evolved as the most promising and effective scientific tool to predict various aspects related to strata mechanics of such workings. Load density,height of caving block, distance of fractured zone ahead of the face, overhang of goaf and mechanical strength of the debris above and below the support base have been found to influence the magnitude of load on supports. Designing powered support has been attempted at the different countries in different methods. This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support resistance requirement in the context of major strata control experiences gained worldwide. The theoretical explanation of the mechanism of roof caving is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata mechanics analysis and monitoring techniques.展开更多
文摘(接2018年12期96页)1.7剪力破坏(Shear fracturing along fissures and strain wave-generated cracks)[14]即在天然裂隙及震波产生裂隙间之剪力破坏。每一岩体飞离时相互间会有一剪力破坏,原因为岩块彼此间抛掷时的不同速度,造成额外的破碎,当同一排中炮孔齐发时此垂直剪力破碎最小,如图7所示。1.8岩块间彼此碰撞的破碎(Fracturing by in-flight collisions)[8]在坑道爆炸中较露天阶段显著,原因为坑道先炸向拔心所提供的空间再转向九十度(90°)排向隧道面,互撞速度为高,飞奔的岩块彼此碰撞造成额外之破碎。
文摘Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving technique and support resistance has evolved as the most promising and effective scientific tool to predict various aspects related to strata mechanics of such workings. Load density,height of caving block, distance of fractured zone ahead of the face, overhang of goaf and mechanical strength of the debris above and below the support base have been found to influence the magnitude of load on supports. Designing powered support has been attempted at the different countries in different methods. This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support resistance requirement in the context of major strata control experiences gained worldwide. The theoretical explanation of the mechanism of roof caving is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata mechanics analysis and monitoring techniques.
