Investigation of overburden behaviour for grout injection to control mine subsidence  

作　　者：Shen Baotang Poulsen Brett 

机构地区：[1]CSIRO Earth Science and Resource Engineering, Brisbane, QLD 4069, Australia

出　　处：《International Journal of Mining Science and Technology》2014年第3期317-323,共7页矿业科学技术学报（英文版）

基　　金：sponsored by ACARP, BHP Billiton Illawarra Coal and CSIRO

摘　　要：This paper describes a field and numerical investigation of the overburden strata response to underground longwall mining, focusing on overburden strata movements and stress concentrations.Subsidence related high stress concentrations are believed to have caused damage to river beds in the Illawarra region, Australia. In the field study, extensometers, stressmeters and piezometers were installed in the overburden strata of a longwall panel at West Cliff Colliery. During longwall mining, a total of1000 mm tensile deformation was recorded in the overburden strata and as a result bed separation and gaps were formed. Bed separation was observed to start in the roof of the mining seam and gradually propagate toward the surface as the longwall face advanced. A substantial increase in the near-surface horizontal stresses was recorded before the longwall face reached the monitored locations. The stresses continued to increase as mining advanced and they reached a peak at about 200 m behind the longwall face. A numerical modelling study identified that the angle of breakage(i.e., the angle of the boundary of caved zone) behind the longwall face and over the goaf was 22–25° from vertical direction. This is consistent with the monitoring results showing the high gradient of stresses and strains on the surface150–320 m behind the mining face.This paper describes a field and numerical investigation of the overburden strata response to underground longwall mining, focusing on overburden strata movements and stress concentrations. Subsidence related high stress concentrations are believed to have caused damage to river beds in the Illawarra region, Australia. In the field study, extensometers, stressmeters and piezometers were installed in the overburden strata of a longwall panel at West Cliff Colliery. During longwall mining, a total of 1000 mm tensile deformation was recorded in the overburden strata and as a result bed separation and gaps were formed. Bed separation was observed to start in the roof of the mining seam and gradually propagate toward the surface as the longwall face advanced. A substantial increase in the near-surface horizontal stresses was recorded before the longwall face reached the monitored locations. The stresses continued to increase as mining advanced and they reached a peak at about 200 m behind the longwall face. A numerical modelling study identified that the angle of breakage （i.e., the angle of the boundary of caved zone） behind the longwall face and over the goaf was 22-25？ from vertical direction. This is con-sistent with the monitoring results showing the high gradient of stresses and strains on the surface 150-320 m behind the mining face.

关 键 词：Longwal mining Overburden movement Stress SUBSIDENCE Grout injection 

分 类 号：TD823.4[矿业工程—煤矿开采]