Numerical study on disturbance of longwall mining to stress state in the rock mass

摘要

In longwall mining, stope voids are filled by caving of the roof strata. Caving causes enormous stress concentrations in the host rocks and results in rock fracturing and large convergences in maingates, Nowadays, it is obvious that stress concentration is a significant controlling factor in many of the longwall mining collapses. Stress concentrations in main-gates, chain and barrier pillars are of particular concern. Stresses can not transmit through unconsolidated caved materials. Therefore stress concentrations in maingates and pillars are associated with the consolidation degree of the caved rock in goafs and as well as the geometry of the caved space in the rock mass.