Acoupled biharmonic spline and linear interpolation algorithm was proposed to create a three-dimensional smooth deposit model with minimal curvature containing grade and position data. To obtain the optimal technical ...Acoupled biharmonic spline and linear interpolation algorithm was proposed to create a three-dimensional smooth deposit model with minimal curvature containing grade and position data. To obtain the optimal technical parameters, such as cuttingheight and drum diameter, a virtual longwall mining procedure was modelled by simulating the actual fully mechanized longwall mining process. Based on the above work, a bauxite deposit in a longwall mining panel was modelled by scattered grade data from ores sampled on the entry wall. The deposit was then demarcated by industrial indexes and sliced according to the virtual longwallmining procedure. The results show that the proposed interpolation algorithm can depict the stratiform structure of bauxite depositsand that the uncovered bauxite deposit has high proportions of high-grade and rich ore. The ranges of optimal cutting height and drum diameters are 1.72-2.84 m and 1.42-1.72 m, respectively. Finally, an intellectualized longwall mining procedure was designed to guide the mining process with the lowest dilution and loss rates.展开更多
As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mini...As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.展开更多
The water resisting property of aquiclude is the key factor of water conservation and safety mining, and the mining induced cracks in aquiclude is major factor of water resisting property. The aquiclude is composed by...The water resisting property of aquiclude is the key factor of water conservation and safety mining, and the mining induced cracks in aquiclude is major factor of water resisting property. The aquiclude is composed by loess layer and red clay layer in Yushuwan Coal Mine, and the water reaction property of clay and loess of aquiclude was tested by soil mechanics method. The permeability coefficient of the loess is 0.856 m/d and the clay is 0.434 m/d. The dilatability coefficient of the loess is 16.1% and the clay is 14.6%. Through physical solid-liquid simulation with whole stress-stain similarity, the distribution of ＂downward crack zone＂ and ＂upward crack zone＂ was found to be the major factor of aquiclude stability. The downward crack closing length is about 30% of the downward crack length. The expanding of clay and loess with water are principal factors of downward crack closing. At last, the mechanical model of downward crack closing was constructed, and the criterion of crack closing was put forward at all. This work will provides the theoretical base for aquiclude stability research and safety mining in shallow seam.展开更多
基金Project(11472311)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by the Innovation Driven Plan of Central South University of ChinaProject(2015zzts083)supported by the Fundamental Research Funds for the Central Universities of Central South University,China
文摘Acoupled biharmonic spline and linear interpolation algorithm was proposed to create a three-dimensional smooth deposit model with minimal curvature containing grade and position data. To obtain the optimal technical parameters, such as cuttingheight and drum diameter, a virtual longwall mining procedure was modelled by simulating the actual fully mechanized longwall mining process. Based on the above work, a bauxite deposit in a longwall mining panel was modelled by scattered grade data from ores sampled on the entry wall. The deposit was then demarcated by industrial indexes and sliced according to the virtual longwallmining procedure. The results show that the proposed interpolation algorithm can depict the stratiform structure of bauxite depositsand that the uncovered bauxite deposit has high proportions of high-grade and rich ore. The ranges of optimal cutting height and drum diameters are 1.72-2.84 m and 1.42-1.72 m, respectively. Finally, an intellectualized longwall mining procedure was designed to guide the mining process with the lowest dilution and loss rates.
基金sponsored by the National Natural Science Foundation of China (No.50974053)Pennsylvania Service Corporation at Waynesburg,USA
文摘As mining depth becomes deeper and deeper,the possibility of undermining overburden aquifers is increasing.It is very important for coal miners to undertake studies on the height of fractured zone during longwall mining and the effects of longwall mining on the underground water while mining under surface water bodies and underground aquifers.In order to study this problem,piezometers for monitoring underground water levels were installed above the longwall panels in an American coalmine.Large amounts of pre-mining,during mining and post-mining monitoring data were collected.Based on the data,the heights of fractured zones were obtained and the effects of longwall mining on the underground water were studied.The results demonstrate that when the piezometer monitoring wells had an interburden thickness of less than 72.7 m,the groundwater level decreased immediately to immeasurable levels and the wells went dry after undermining the face of longwall.The height of the fractured zone is 72.7-85.3 m in the geological and mining conditions.The results also show that the calculated values of fractured zones by the empirical formulae used in China are smaller than the actual results.Therefore,it is not always safe to use them for analyses while mining under water bodies.
文摘The water resisting property of aquiclude is the key factor of water conservation and safety mining, and the mining induced cracks in aquiclude is major factor of water resisting property. The aquiclude is composed by loess layer and red clay layer in Yushuwan Coal Mine, and the water reaction property of clay and loess of aquiclude was tested by soil mechanics method. The permeability coefficient of the loess is 0.856 m/d and the clay is 0.434 m/d. The dilatability coefficient of the loess is 16.1% and the clay is 14.6%. Through physical solid-liquid simulation with whole stress-stain similarity, the distribution of ＂downward crack zone＂ and ＂upward crack zone＂ was found to be the major factor of aquiclude stability. The downward crack closing length is about 30% of the downward crack length. The expanding of clay and loess with water are principal factors of downward crack closing. At last, the mechanical model of downward crack closing was constructed, and the criterion of crack closing was put forward at all. This work will provides the theoretical base for aquiclude stability research and safety mining in shallow seam.
