An underground coal mine located in New South Wales has a target coal seam located 160-180 m deep directly below a 16-20 m thick conglomerate unit that has been associated with significant periodic weighting events on...An underground coal mine located in New South Wales has a target coal seam located 160-180 m deep directly below a 16-20 m thick conglomerate unit that has been associated with significant periodic weighting events on the Iongwall face. As part of the investigations to better understand the causes of periodic weighting at the mine. inclinometers capable of measuring horizontal shear movements through the full section of the overburden strata were installed ahead of mining at two locations approximately 1 km apart above the centre of two iongwall panels. These inclinometers were monitored as the longwall approached each site. This paper presents the details of the installation, the results of the inclinometer monitoring at both sites, and the insights that these measurements provide for overburden behaviour about longwall panels. Horizontal shear movements were observed to develop on shear horizons that correlate closely across the two sites suggesting a mechanism that is consistent across a large area of the mine. Shear movements were observed to develop on a single horizon near the top of the conglomerate strata that was mobilised almost immediately after initial formation of the longwall goal at a distance of 425 m ahead of the longwall face.展开更多
Based on the character of upward slicing backfilling mining and the condition of Gonggeyingzi coal mine in Inner Mongolia,this paper describes the studies of the strata behavior and the stress distribution in the proc...Based on the character of upward slicing backfilling mining and the condition of Gonggeyingzi coal mine in Inner Mongolia,this paper describes the studies of the strata behavior and the stress distribution in the process of backfilling mining in extra-thick coal seams.This was achieved by setting up and analyzing the elastic foundation beam model using the ABAQUS software.The results show that:(1) With the gradual mining of different slices,the roof appears to bend continuously but does not break.The vertical stress in the roof decreases and the decreasing amplitude reduces,while the tensile stress in the roof grows with the mining slices and the maximum tensile stress will not exceed the allowable tensile stress.(2) The front vertical stress at the working face exceeds the rear vertical stress and both show a trend of decrease with decreasing amplitude of decrease.(3) The slices mined early have more influence on the surrounding rock than the later ones.Similarly,the strata behavior experiences the same trend.The field measured data show that the roof does not break during the mining process,which is consistent with the conclusion.展开更多
文摘An underground coal mine located in New South Wales has a target coal seam located 160-180 m deep directly below a 16-20 m thick conglomerate unit that has been associated with significant periodic weighting events on the Iongwall face. As part of the investigations to better understand the causes of periodic weighting at the mine. inclinometers capable of measuring horizontal shear movements through the full section of the overburden strata were installed ahead of mining at two locations approximately 1 km apart above the centre of two iongwall panels. These inclinometers were monitored as the longwall approached each site. This paper presents the details of the installation, the results of the inclinometer monitoring at both sites, and the insights that these measurements provide for overburden behaviour about longwall panels. Horizontal shear movements were observed to develop on shear horizons that correlate closely across the two sites suggesting a mechanism that is consistent across a large area of the mine. Shear movements were observed to develop on a single horizon near the top of the conglomerate strata that was mobilised almost immediately after initial formation of the longwall goal at a distance of 425 m ahead of the longwall face.
基金sponsored by the National Key Basic Research Program of China (No.2013CB227905)Qinglan Projects of Jiangsu Province
文摘Based on the character of upward slicing backfilling mining and the condition of Gonggeyingzi coal mine in Inner Mongolia,this paper describes the studies of the strata behavior and the stress distribution in the process of backfilling mining in extra-thick coal seams.This was achieved by setting up and analyzing the elastic foundation beam model using the ABAQUS software.The results show that:(1) With the gradual mining of different slices,the roof appears to bend continuously but does not break.The vertical stress in the roof decreases and the decreasing amplitude reduces,while the tensile stress in the roof grows with the mining slices and the maximum tensile stress will not exceed the allowable tensile stress.(2) The front vertical stress at the working face exceeds the rear vertical stress and both show a trend of decrease with decreasing amplitude of decrease.(3) The slices mined early have more influence on the surrounding rock than the later ones.Similarly,the strata behavior experiences the same trend.The field measured data show that the roof does not break during the mining process,which is consistent with the conclusion.
