Innovation and future of mining rock mechanics

Huang

Energy Science & Engineering

et al. 2021

Recently, concerns regarding coal resource waste and safety mining have grown worldwide. The no-pillar mining method without advance tunneling, known as the N00 longwall mining method, represents a rational alternative in this regard.Since the 20th century, coal mining technology has undergone long-term development in China. The mining methods used in China's coal industry can be classified into three types: longwall mining, gob-side entry retaining, and N00 longwall mining.The longwall mining method, which originated in Britain during the early 18th century, was first used in China in the 1930s and has been developed for approximately 90 years. It has become one of the landmark achievements in the field of coal mining in China. 1,2 However, a large coal pillar measuring 20-50 m and double advance tunneling roadways should be set up before stopping a working face when using this mining method. This results in low coal recovery rates and mining productivity. Hence, the contradiction between this mining method and China's energy characteristics has become more prominent.

Section: Experimental Conditionsmentioning

confidence: 99%

mentioning

confidence: 99%

Validation study of no‐pillar mining method without advance tunneling: A case study of a mine in China

Huang

Energy Science & Engineering

et al. 2021

“…e effect of filling on the stress distribution of stope is studied. Fang et al [5] collected undisturbed soil samples from tertiary mudstone, studied the creep process and failure mechanism of surrounding rock through indoor model test of underground tunnel, proposed influence of time and stress on creep parameters and mechanical parameters, introduced the concepts of over stress difference and time product, and established a damage model considering time and stress state [6][7][8]. A model describing the whole process of rock creep is introduced, which can correspond to each stage of rock creep.…”

Section: Instructionmentioning

confidence: 99%

Analysis of Surrounding Rock Creep Effect on the Long‐Term Stability of Tunnel Secondary Lining

Zhang

Wei

Zhang

2021

Shock and Vibration

The secondary lining failure of deep buried soft rock tunnel often occurs, which is obviously related to the time factor. The formation mechanism of this phenomenon is studied in this paper. Therefore, the combination of in situ stress measurement and neural network inversion is used to analyze the distribution characteristics of in situ stress. At the same time, the creep characteristics of surrounding rock are tested in laboratory, and the key parameters are obtained. Combined with the characteristics of surrounding rock, the calculation model is established by using discrete element simulation technology and considering the joints of surrounding rock. According to the above multiple information, the stress characteristics of the secondary lining in different time periods are analyzed creatively. Finally, the method of setting arch and adding anchor bolt in key parts is proposed, and significant effect results are obtained.

Mathematical Problems in Engineering

“…In recent years, with the decreasing of conventional oil and gas resources, the world has increased the exploration and development of unconventional energy, especially tight oil and gas [1][2][3][4][5][6][7][8][9]. Compared with conventional sandstone reservoirs, tight sandstone reservoirs are characterized by small pore throats (micro-and nanoscale), complex pore structure, and strong micro-and macroheterogeneity [10].…”

Section: Introductionmentioning

confidence: 99%

Difference of Microfeatures among Diagenetic Facies in Tight Sandstone Reservoirs of the Triassic Yanchang Formation in the Midwestern Region, Ordos Basin

Shi

Xiaolong

Xie

et al. 2021

Based on the background of sedimentary characteristics, a large amount of core and thin section analysis, taking Chang 6 reservoir of Yanchang Formation in the central and western Ordos Basin as an example, through the application of scanning electron microscopy, high-pressure mercury injection, nuclear magnetic resonance and microscopic water drive oil model, and other experimental test methods, the diagenetic facies types and microscopic pore structure characteristics of tight sandstone reservoirs are discussed and analyzed in depth. The results show that the average porosity loss rate caused by early diagenesis compaction in the study area is 50.62%, which is the main reason for reservoir compactness. The cementation further causes porosity loss, and the later dissolution increases the reservoir space in the study area to a certain extent. Different diagenetic facies reservoirs not only have obvious differences in porosity evolution characteristics but also have significant differences in pore throat radius distribution characteristics, movable fluid occurrence characteristics, and water drive oil characteristics. The pore throat distribution with radius greater than R50∼R60 determines the permeability. The difference in movable fluid saturation mainly depends on the connectivity of the relative large pore space corresponding to the relaxation time greater than the cut-off value of T2. The size of pore throat radius has a good control effect on water flooding efficiency.