As coal mining depths increase, rockbursts pose a significant threat to the safety of mine operations. Addressing challenge safely and steadily advancing excavation faces amid rockburst hazards, this study assesses current state reinforcement support technology for rockburst-prone roadways. It scrutinizes concept roadway anti-rockburst hydraulic support, design, integration with surrounding rock mass. The research delineates key directions enhancing systems, including mechanical mechanisms...

Abstract Coalbed methane, which is a significant potential unconventional source of energy, exhibits considerable challenges in the implementation exploration and production process, especially degasification low permeability coal seams with high gas concentrations. Due to difficulties extraction, long mining period extraction concentration soft outburst seams, improvement method using presplitting blasting technology multiple boreholes has been proposed applied improve seam, achieved by...

With mining technology and mechanization degree being improving, fully mechanized caving (FCM) has become a main method for thick coal seam extraction in China. However, roof‐coal characteristics turn restrict its recovery efficiency, especially the with complicated structure (CCS), that is, comprises hard or soft gangue. In order to explore key factors influencing characteristics, related research work been conducted as follows: firstly, mechanical model of CCS established, which indicates...

The zoning of the coal seam gas is zonal, which has a significant impact on prominent prediction indicators, resulting in different results for same indicators soft and hard coal. In this paper, are highlighted. adsorption desorption rules outburst its influence sensitivity outstanding index studied. show that: (1) initial larger than that coal; (2) an exponential function relationship with pressure; (3) different. And concluded rate faster K1 Δh2 increase equilibrium more reliable Δh2.

Mine dust is one of the main disasters that threatens safety coal mine production, deteriorates underground working environment and induces various occupational diseases. Based on harm identified current domestic foreign dust-proof technology, technical research foam reduction reviewed; advantages disadvantages are also discussed. According to experimental exploration study flow characteristics, process device nozzle separation was adopted, some site tests were conducted in fully mechanized...

Abstract Understanding the stress‐cracks‐permeability evolution law inside coal body under cyclic loading is significant to optimize gas extraction technology and disasters prevention technology. In order explore influence of mining stress on mechanical behavior permeability variation gas‐bearing seams, experiments evolution, deformation law, acoustic emission ( AE ) characteristics samples with different level frequency were carried out. These results indicate that higher level, shorter...

A decrease in the viscosity of a solution sodium carboxymethyl cellulose (CMC-Na) is commonly encountered problem coalbed methane (CBM) pressure measurement with an apron CMC-Na sealer and capsule sealer. Studies have shown that factors can reduce include hydrogen ion concentration index (pH), environmental temperature, drilling sealing time, high-pressure CBM gas environment. In this study, homemade instrument for measuring under high was used to determine change laws different conditions,...

Abstract The prediction of dangerous hazards in working faces is an important link to prevent coal and gas outbursts. Improving the accuracy predictive indicators great significance for reducing phenomenon being prominently below critical value ensuring safe production. fixed-size desorption index K 1 one face outburst prediction. Based on diffusion theory physical meaning samples, mathematical expression established by self-developed high/low temperature pressure swing adsorption-desorption...

In order to further explore the relationship between excavation speed and damage of surrounding rocks dynamic manifestation, stress paths unloading confining pressure loading axial were designed based on changes in roadway rock this study. Additionally, mechanical properties energy evolution law coal body investigated under various rates. As rate increased, including failure strength, pressure, strain, horizontal strain tended decrease at rupture stage, while volume elastic modulus...

To study the mechanical damage characteristics of rock under effect subversion, a series experiments, including both uniaxial and triaxial compression experiments various levels water content were performed. In this study, researchers investigate impact on rock, based compliance variants to Weibull statistic distribution, Drucker–Prager strength rule, aiming construct constitutive model joint load moisture. addition, established is tested in experiment. According test results, during initial...

Gas occurrence in coal seams shows zonation, and the outburst risk prediction index is significantly affected by seam gas. For different mine, sensitivity of inconsistent, area same mine can present sensitivities to index. In this study, we measured industrial analysis coals determined degree each using samples with particle size 1 ∼ 3 mm. The relationships between equilibrium gas pressure desorption drill cuttings, cuttings adsorption pressure, critical values indexes were also analyzed...

Coal is affected by the concentrated stress disturbance of mining, drilling hole formation, and coal shrinkage splitting gas desorption from wall; these result in a large number secondary cracks that collect leak gas. As result, it difficult for seam sealing process to meet engineering quality requirements, which results problems such as low concentration during extraction process. In this paper, based on analysis pore fissure characteristics, view current situation drainage seam, combined...

Based on the dynamic expressions of permeability and porosity coal seam derived in paper, a multiphysical field coupling numerical model gas migration under interaction stress seepage was established. The drainage project #3 Coal Seam operated by Sima Industry Co., Ltd., selected as study object. Taking different time periods various positions holes into consideration, combined with advance situation 1207 working face Mine, mixed layout scheme featured effective borehole spacing obtained...

Investigating the dilatancy of host rock during stress re-distribution is great sig?nificance for underground engineering, especially salt cavern storages. To formulate variation, some measurements were conducted via unloading tests with ever-reduced confining pressure and constant axial pressure. The results demonstrated that initial had little influence on salt. A larger axis can promote higher temperature would accelerate rate augment total volumetric expansion. dilatancy-damage model was...

Abstract Ni-MH, with high electric energy density and stability, is the main backup battery of mine power supply. To improve estimation accuracy SOC (state charge) prolong its service life, this paper takes single Ni-MH as experimental object, adopts an improved BP neural network that adds adaptive rate momentum term to increase discharged amount electricity. The input characteristics are same temperature, current terminal voltage. According variance error between expected output actual...

Coal mine methane (CMM) emissions from underground coal mines is becoming a global problem since it produces greenhouse gas contributing to warming. It critical reduce low-concentration CMM(LCM) and ventilation air (VAM) emissions, which has become the focus be solved urgently. One of methods utilizing this VAM as fuel by mixing CMM with help porous burning system. In order optimize performance system composed alumina particles, series complex media burners two layers particles were...

As one of the most important unconventional hydrocarbon resources, oil shale has been extracted with a frozen wall to successfully increase production and reduce environmental pollution, which results from harmful liquids in situ conversion processing shale. Thereby, strength permeability are extremely critical chemicals leaching into groundwater. However, can be influenced by periodic freeze-thaw cycles. In order investigate damage deterioration characteristics samples after various cycles,...