Evaluation of structural damage and gas transportability change in coal subjected to ultrasound stimulation using image-based modeling and permeability tests

Cracking Behavior and Stress Field Evolution in Coal Specimens Containing Bedding under Uniaxial Compression

“…20 Furthermore, it offers theoretical support and a scientific foundation for comprehending the mechanisms behind various dynamic disasters in the coal seam, providing effective early warning of disasters, and implementing prevention and control measures. 21 Coal is a geological material that undergoes various geological tectonic processes during its formation, leading to the transformation of intact coal rock into a geological body with varying degrees of damage, such as noticeable bedding structures. 22 The presence of bedding structures significantly influences the mechanical properties of coal rock, including compressive strength, elastic modulus, and cohesion, resulting in apparent anisotropic characteristics.…”

“…Over long geological periods, various structural planes such as bedding, fissures, and faults form within the coal seam due to geological tectonic processes. , Among these structures, bedding is the most widespread and exerts a decisive influence on the stability, recoverability, and gas flow conditions of the coal seam. − The presence of bedding structure is a key factor impacting the strength and deformation characteristics of the coal seam, resulting in complex discontinuities, heterogeneity, and strong anisotropy in the coal seam, as well as altering its stress state. − Consequently, studying the evolution of damage characteristics in coal-containing bedding holds practical value in understanding the mechanical deformation and damage features of coal with bedding while also enhancing gas extraction efficiency . Furthermore, it offers theoretical support and a scientific foundation for comprehending the mechanisms behind various dynamic disasters in the coal seam, providing effective early warning of disasters, and implementing prevention and control measures …”

Current Status of Research on the Coal and Gas Outburst Control Technology of Hydration and Anhydrous

“…Coal and gas outburst accidents have occurred in mining areas in many countries. Among them, China is one of the countries with the most frequent coal and gas outburst accidents in the world. , With the continuous increase of coal production, the reserves of shallow coal continue to decrease, the depth of coal seam mining continues to deepen, the ground stress and gas content of coal seam gradually increase, and the permeability of coal seam gradually decreases. − This trend aggravates the intensity and frequency of coal and gas outburst disasters, which easily cause major accidents.…”

“… 2 , 3 With the continuous increase of coal production, the reserves of shallow coal continue to decrease, the depth of coal seam mining continues to deepen, the ground stress and gas content of coal seam gradually increase, and the permeability of coal seam gradually decreases. 4 − 6 This trend aggravates the intensity and frequency of coal and gas outburst disasters, which easily cause major accidents.…”

Gas Dispersion Coefficient Test System and Dimensionless Inversion Method for Porous Media

“…China is the largest coal producer and consumer in the world, and the share of coal in primary energy consumption has been greater than 50% for a long time. − As the depth and intensity of coal mining increase, mining conditions have become more and more complex and dangerous. − Spontaneous coal combustion is one of the most important threats, which mainly occurs in the gob area of longwall mining face. , The interior of the gob area is full of rocks after the collapse of the roof, forming a complex porous medium structure. − In addition, a large amount of crushed coal is left in the gob area. The fresh air leaking into the gob area oxidizes with the crushed coal, and the heat released from the reaction gradually accumulates and eventually causes a fire, leading to huge human and property losses. , …”