Top-coal caving technology is a productive and efficient method in modern mechanized coal mining, the study of coal-rock recognition is key to realizing automation in comprehensive mechanized coal mining. In this paper we propose a new discriminant analysis framework for coal-rock recognition. In the framework, a data acquisition model with vibration and acoustic signals is designed and the cav...

Over 31% of the fossil fuel energy consumed in the United States comes from natural gas—even more important than coal, which accounts for 25% of the total fossil energy consumed. Unlike coal and petroleum, which can easily be shipped around the world by vessel, natural gas is almost exclusively transported by pipeline. As a result, the vast majority (over 95%) of the natural gas consumed in the...

Coal dust explosions in underground coal mines are pre­ vented by a generous application of rock dust (usually lime­ stone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents fl ame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of ex­ plosion experiments using various coal dust and limes...

subject analysis of the potential of spontaneous combustion in coal layers with analytical and numerical methods has been always considered as a difficult task because of the complexity of the coal behavior and the number of factors influencing it. empirical methods, due to accounting for certain and specific factors, have not accuracy and efficiency for all positions. the rock engineering syst...

Considerable fracturing occurs around the deep mine stopes because of the mining induced stresses superimposed on the high overburden stresses encountered at these depths. The frequency and orientation of fracturing is largely affected by the presence of geological structures, as well as the stope layout and mining configurations. Being able to accurately predict the effect of these interfaces ...

Understanding how grain and powder lubrication affect rock friction and fracture dilation, and how microscopic fractures develop according to fault activation may directly improve our capabilities in exploration and stimulation of oil and gas reservoirs. Using a novel rotary shear testing apparatus specifically designed and assembled to conduct experiments inside an X-ray micro computed tomogra...

The deformation and fracturing of coal rock is a crucial part dynamic disasters accompanied by variations in the electrical field rock. In this study, self-potential characteristics were measured to dynamically monitor spatiotemporal evolution fracturing. By using an MTS816 mechanics test system, AE acoustic emission system self-developed SEMOS-LAB experimental synchronous measurements self-pot...

We present a contribution on the risk of hydraulic fracturing in CO2 geological storage using an analytical model of hydraulic fracturing in weak formations. The work is based on a MohrCoulomb dislocation model that is extended to account for material with fracture toughness. The complete slip process that is distributed around the crack tip is replaced by superdislocations that are placed in t...

The purpose of this study is to the damage and fracturing effects high-voltage discharge on coal-rock mass under action hydrostatic pressure. Based traditional evolution model change effective bearing area stress around microcrack a microscopic scale, expression macroscopic variation electrohydraulic coupling was derived, its constitutive relation established. pulse water shock test conditions ...

Fully mechanized top-coal caving mining with high height, hard roofs and strong pressure are popular in the Shendong area, China. The occurrence of dynamic disasters, such as rock burst, coal gas outburst, mine earthquakes goaf hurricanes during exploitation process under roof conditions, pose a threat to safe production mines. In this study, characteristics overburden fracture fully height stu...