Ground crack and subsidence were investigated in Kaiyang Phosphorus Mine as an example. Contribution factors to cause ground crack and mining subsidence were studied, including mining method, mining depth and ore thic...Ground crack and subsidence were investigated in Kaiyang Phosphorus Mine as an example. Contribution factors to cause ground crack and mining subsidence were studied, including mining method, mining depth and ore thickness and stope size, dip angle of orebody, geological structure, nature of overburden and water contents, and roof supports, etc. Countermeasures against cracks and subsidence were put forward. The uniaxial compressive strength of compounded phosphorus gypsum after 28 d of curing period was tested to be more than 1 MPa. Phosphorus gypsum can be used as materials for the backfill of stope. By comparison and numerical simulation, cut and fill mining method with middle-deep drilling holes and ore transportation by blasting force was selected as the optimum mining method in Kaiyang Phosphorus Mine.展开更多
The effect of geological uncertainty on the development and mining of underground coal deposits is a key issue for longwall mining, as the presence of faults generates substantial monetary losses. This paper develops ...The effect of geological uncertainty on the development and mining of underground coal deposits is a key issue for longwall mining, as the presence of faults generates substantial monetary losses. This paper develops a method for the conditional simulation of fault systems and uses the method to quantify and assess fault uncertainty. The method is based on the statistical modelling of fault attributes and the simulation of the locations of the centres of the fault traces. Fault locations are generated from the thinning of a Poisson process using a spatially correlated probability field. The proposed algorithm for simulating fault traces takes into account soft data such as geological interpretations and geomechanical data. The simulations generate realisations of fault populations that reproduce observed faults, honour the statistics of the fault attributes, and respect the constraints of soft data, providing the means to thereby model and assess the related fault uncertainty.展开更多
This paper will present a detailed analysis of the deformation mechanism and stability assessment of the slope through field investigations, numerical modeling and measurements. Field investigation indicated that thre...This paper will present a detailed analysis of the deformation mechanism and stability assessment of the slope through field investigations, numerical modeling and measurements. Field investigation indicated that three thin coal seams encountered large mined-out area at one side and free surface of hill slope at the other side, which lead to the caving of roof strata movement, ground movement and crown crack along the preferred orientations of joints. The three-dimensional numeri- cal modeling study on the case demonstrated that the plasticity failure occurred gradually along with the extension of mined-out area in depth. When the depth of mining reached the verge defined by the seismic prospecting method, a large mount of tension failure occurred on the crown of the slope. The factor of safety was 1.36 calculated by the shear strength reduction technique, which indicated the slope was in stable state. The measurement showed that the residual deformation occurred before 1998 and became stable subsequently, which indicated that the residual deformation almost finished and the slope is in stable state.展开更多
Recent years, underground mining method is becoming popular because of its potentially high productivity and efficiency. In this method, a mining machinery; load haul dump(LHD), is used as both an excavator and a tran...Recent years, underground mining method is becoming popular because of its potentially high productivity and efficiency. In this method, a mining machinery; load haul dump(LHD), is used as both an excavator and a transporter of ore. This paper proposes a distributed system that realizes the excavation and transport functions with separated vehicles, an excavator and a transporter. In addition, this research proposes a mining map and configurations suitable for the proposed distributed system. To evaluate the productivity of the proposed system, a simulation environment has been developed. Analysis using the simulator reveals what performance factors of the excavator and the transporter have large impacts on the productivity. Simulation results also demonstrate the difference of potential between LHD system and the distributed system that can be explained based on their functions allocation.展开更多
Streamflow in the Kuye River basin has been sharply reduced by the effects of climate change and human activities.Since 1997,the intensification of coal mining has resulted in substantial reductions to streamflow alon...Streamflow in the Kuye River basin has been sharply reduced by the effects of climate change and human activities.Since 1997,the intensification of coal mining has resulted in substantial reductions to streamflow alongside an ever-increasing demand for water.In this study,we present a derived statistical method,incorporating the Mann-Kendall and Pettitt method(MK-P) and the Soil and Water Assessment Tool(SWAT),and apply it to estimating the streamflow reductions caused by underground mining for coal in the Kuye River basin.The results show that underground mining is an important cause of the streamflow reductions observed since1997,being responsible for reductions of 21.15 mm/yr(~56%of the total) during 1997-2009.The results of the SWAT simulation were assessed by several performance criteria:Nash-Suttcliffe Efficiency(Nse),correlation coefficient(R^2),relative error(RE),P-factor and Pv-factor.The close match between the simulations and observed data supports the reasonability of our findings.We suggest that engineering strategies be adopted to limit streamflow loss into goafs via fractured zones in the coalfield.展开更多
基金Projects(50574098, 50404010) supported by the National Natural Science Foundation of China project(05jj10010) supported by the Hunan Provincial Natural Science Foundation of Distinguished Young Scholars
文摘Ground crack and subsidence were investigated in Kaiyang Phosphorus Mine as an example. Contribution factors to cause ground crack and mining subsidence were studied, including mining method, mining depth and ore thickness and stope size, dip angle of orebody, geological structure, nature of overburden and water contents, and roof supports, etc. Countermeasures against cracks and subsidence were put forward. The uniaxial compressive strength of compounded phosphorus gypsum after 28 d of curing period was tested to be more than 1 MPa. Phosphorus gypsum can be used as materials for the backfill of stope. By comparison and numerical simulation, cut and fill mining method with middle-deep drilling holes and ore transportation by blasting force was selected as the optimum mining method in Kaiyang Phosphorus Mine.
文摘The effect of geological uncertainty on the development and mining of underground coal deposits is a key issue for longwall mining, as the presence of faults generates substantial monetary losses. This paper develops a method for the conditional simulation of fault systems and uses the method to quantify and assess fault uncertainty. The method is based on the statistical modelling of fault attributes and the simulation of the locations of the centres of the fault traces. Fault locations are generated from the thinning of a Poisson process using a spatially correlated probability field. The proposed algorithm for simulating fault traces takes into account soft data such as geological interpretations and geomechanical data. The simulations generate realisations of fault populations that reproduce observed faults, honour the statistics of the fault attributes, and respect the constraints of soft data, providing the means to thereby model and assess the related fault uncertainty.
基金Supported by the National Natural Science Foundation of China for Youth （51004065） the National Basic Research Program of China （2012CB724208）
文摘This paper will present a detailed analysis of the deformation mechanism and stability assessment of the slope through field investigations, numerical modeling and measurements. Field investigation indicated that three thin coal seams encountered large mined-out area at one side and free surface of hill slope at the other side, which lead to the caving of roof strata movement, ground movement and crown crack along the preferred orientations of joints. The three-dimensional numeri- cal modeling study on the case demonstrated that the plasticity failure occurred gradually along with the extension of mined-out area in depth. When the depth of mining reached the verge defined by the seismic prospecting method, a large mount of tension failure occurred on the crown of the slope. The factor of safety was 1.36 calculated by the shear strength reduction technique, which indicated the slope was in stable state. The measurement showed that the residual deformation occurred before 1998 and became stable subsequently, which indicated that the residual deformation almost finished and the slope is in stable state.
文摘Recent years, underground mining method is becoming popular because of its potentially high productivity and efficiency. In this method, a mining machinery; load haul dump(LHD), is used as both an excavator and a transporter of ore. This paper proposes a distributed system that realizes the excavation and transport functions with separated vehicles, an excavator and a transporter. In addition, this research proposes a mining map and configurations suitable for the proposed distributed system. To evaluate the productivity of the proposed system, a simulation environment has been developed. Analysis using the simulator reveals what performance factors of the excavator and the transporter have large impacts on the productivity. Simulation results also demonstrate the difference of potential between LHD system and the distributed system that can be explained based on their functions allocation.
基金supported by the National Natural Science Foundation of China(Grant Nos.51309107,E090105,41130639 and 51179045)the Public Welfare Program(Grant Nos.201501022 and 201301068)+1 种基金the Fundamental Research Funds for the Central Public Welfare Research Institutes(Grant No.HKY-JBYW-2013-19)the Fundamental Research Funds for the Central Universities(Grant Nos.2014B34914 and 2015B28514)
文摘Streamflow in the Kuye River basin has been sharply reduced by the effects of climate change and human activities.Since 1997,the intensification of coal mining has resulted in substantial reductions to streamflow alongside an ever-increasing demand for water.In this study,we present a derived statistical method,incorporating the Mann-Kendall and Pettitt method(MK-P) and the Soil and Water Assessment Tool(SWAT),and apply it to estimating the streamflow reductions caused by underground mining for coal in the Kuye River basin.The results show that underground mining is an important cause of the streamflow reductions observed since1997,being responsible for reductions of 21.15 mm/yr(~56%of the total) during 1997-2009.The results of the SWAT simulation were assessed by several performance criteria:Nash-Suttcliffe Efficiency(Nse),correlation coefficient(R^2),relative error(RE),P-factor and Pv-factor.The close match between the simulations and observed data supports the reasonability of our findings.We suggest that engineering strategies be adopted to limit streamflow loss into goafs via fractured zones in the coalfield.
