In underground coal mining,surface subsidence disasters are likely to be induced.Especially,under the condition of multi-seam mining,the movement characteristics of the overlying strata are more complex.Once these cha...In underground coal mining,surface subsidence disasters are likely to be induced.Especially,under the condition of multi-seam mining,the movement characteristics of the overlying strata are more complex.Once these characteristics are transmitted to the surface,it is easy to lead to intensified deformation and the appearance of ground fissures.This not only causes damage to surface buildings but also may have irreversible impacts on the aquifer.Taking 1208#working face of Hongyang No.3 Coal Mine as a case in study,this paper uses the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-InSAR)technology to systematically monitor and analyze the surface subsidence characteristics of the multi-mining area(MMA)and the single-mining area(SMA)changing over time,with a focus on discussing the subsidence laws of the MMA.The comparative analysis results show that:(1)There is an obvious hysteresis in surface subsidence,the position of the subsidence center basically corresponds to that of the working face,but the influence range of subsidence exceeds the boundary of the working face,besides,significant surface subsidence occurred 36 days after mining the No.1208 working face,and the change in the structure of the overlying strata was transmitted to the surface;(2)Compared with the single-mining area(SMA),the maximum subsidence rate(MSR)and the maximum subsidence value(MSV)in the multi-mining area(MMA)are higher,and both the subsidence center and its influence range are significantly expanded;and(3)After the mining of the working face stops,the subsidence rate slows down,but the subsidence increment in the MMA area is still higher than that in the SMA.The above findings deepen the understanding of the evolution mechanism of surface subsidence disasters caused by multiple mining activities,and provide an important basis for the monitoring,prevention and control of subsidence disasters in similar mining areas.展开更多
Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the fac...Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.展开更多
In this paper,the advantage of using numerical models with the strength reduction method(SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated.A coal mine under variable topography from ...In this paper,the advantage of using numerical models with the strength reduction method(SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated.A coal mine under variable topography from the Central Appalachian region is used as a case study.At this mine,unexpected roof conditions were encountered during development below previously mined panels.Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels.Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries.The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations.The SRM-calculated stability factors were compared with observations made during the site visits,and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case.It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines.展开更多
基金supported by the financial support of National Youth Science Fund(NYSF)of China(No.52304218).
文摘In underground coal mining,surface subsidence disasters are likely to be induced.Especially,under the condition of multi-seam mining,the movement characteristics of the overlying strata are more complex.Once these characteristics are transmitted to the surface,it is easy to lead to intensified deformation and the appearance of ground fissures.This not only causes damage to surface buildings but also may have irreversible impacts on the aquifer.Taking 1208#working face of Hongyang No.3 Coal Mine as a case in study,this paper uses the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-InSAR)technology to systematically monitor and analyze the surface subsidence characteristics of the multi-mining area(MMA)and the single-mining area(SMA)changing over time,with a focus on discussing the subsidence laws of the MMA.The comparative analysis results show that:(1)There is an obvious hysteresis in surface subsidence,the position of the subsidence center basically corresponds to that of the working face,but the influence range of subsidence exceeds the boundary of the working face,besides,significant surface subsidence occurred 36 days after mining the No.1208 working face,and the change in the structure of the overlying strata was transmitted to the surface;(2)Compared with the single-mining area(SMA),the maximum subsidence rate(MSR)and the maximum subsidence value(MSV)in the multi-mining area(MMA)are higher,and both the subsidence center and its influence range are significantly expanded;and(3)After the mining of the working face stops,the subsidence rate slows down,but the subsidence increment in the MMA area is still higher than that in the SMA.The above findings deepen the understanding of the evolution mechanism of surface subsidence disasters caused by multiple mining activities,and provide an important basis for the monitoring,prevention and control of subsidence disasters in similar mining areas.
文摘Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.
文摘In this paper,the advantage of using numerical models with the strength reduction method(SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated.A coal mine under variable topography from the Central Appalachian region is used as a case study.At this mine,unexpected roof conditions were encountered during development below previously mined panels.Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels.Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries.The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations.The SRM-calculated stability factors were compared with observations made during the site visits,and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case.It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines.
