of the roof rock, (2) the excavation geometry, and (3) the forces applied to the mine roof. ROCK STRENGTH Rock strength traditionally is estimated from laboratory tests. The uniaxial compressive test is the most commonly used. Figure 1 shows the approximate range of compressive strengths observed in U.S. coal measure rock. Triaxial tests,
During the storage of underground water reservoirs in coal mines, water–rock interaction occurred between mine water and collapsed rocks, resulting in improved mine water quality, but the water–rock process and mechanism have not been clarified. In this study, six sets of simulated experiments were designed to investigate the …
Rock fall. The NIOSH Mining Program is working to combine empirical, laboratory, and numerical studies to advance the state-of-the-art methods for protecting mine workers from all forms of rock fall. Major …
The research related to WRI in underground coal mining mainly focuses on the water inrush form roof and floor, water weakening of roadway surrounding rock (coal …
reservoir capacity and the coordinated development of coal mining and water resources protection in western China. Furthermore, they provide a scientific basis for both basic theoretical research and practical applications in particle packing systems. These systems encompass various materials such as caved ore and rock in metal mines, …
Coal is a black or brownish-black sedimentary rock that can be burned for fuel and used to generate electricity. It is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion (burning). Coal is the largest source of energy for generating electricity in the world, and the most abundant fossil fuel ...
The surrounding rock of a coal mine roof fractures with the excavation of the underground working face in coal mining. These mining-induced fractures are connected and extended upward to form water inrush channels. A water inrush accident may occur when there is a sufficiently large water source. To elucidate the formation mechanisms of …
According to the analysis of structural characteristics of the cover rock in Xiaoyun Coal Mine, because the cover rock of Coal Seam 3 1318 working face was mostly composite rock structure, the ...
Coal mine water inrush threatens mining operations, pollutes the environment, and wastes significant water resources [17], [18]. The Yanzhou mining area is a typical North China-Type coalfield. ... Experimental investigation on mining-induced strain and failure characteristics of rock masses of mine floor. Geomat Nat Haz Risk, 11 (1) …
Glossary of Mining Terminology. A. Abutment - In coal mining, (1) the weight of the rocks above a narrow roadway is transferred to the solid coal along the sides, which act as abutments of the arch of strata spanning the roadway; and (2) the weight of the rocks over a longwall face is transferred to the front abutment, that is, the solid coal ...
Coal mining - Underground mining: In underground coal mining, the working environment is completely enclosed by the geologic medium, which consists of the coal seam and the overlying and underlying strata. ... The science of rock mechanics is well advanced and is useful for understanding such stability problems and for the design of …
Weak, layered, and fragile rock mass formation, if not supported properly, is subject to roof failure thereby affecting safety and productivity in underground coal mines. Though Central Mining Research Institute – Indian School of Mines Rock Mass Rating (CMRI-ISM RMR) based well-defined support design guidelines are established, still …
Rock dusting problems are universal to the coal industry and applicable to all operating underground bituminous coal mines. An explosion can propagate with as little as 0.01 inches of float coal dust on top of pure rock dust, suggesting the need to simultaneously apply rock dust as the mining face advances.
In order to provide a theoretical basis for the design of underground shaft coal pocket and support parameters in coal mines, a mechanical model and a dynamic analysis of the silo wall are established based on the engineering background of Ganhe Coal Mine. The numerical calculation is carried out by using the new model. The back …
Mine fires are a serious natural disaster that can occur during coal mine operation. They have a great impact on coal resources, the environment, and the health of workers (Roy et al. 2019; Liu and Zhou 2010; Song and Kuenzer 2014; Chen et al. 2012; Liu et al. 2022; Qin et al. 2022; Liu et al. 2019; Peng et al. 2022; Nie et al. 2021).Coal …
3. Numerical Calculation Model and Results 3.1. Numerical Calculation Model and Its Parameters. According to the comprehensive histogram of 9103 working face in Junde Coal Mine, the initial three-dimensional numerical model is established with the help of 3DEC numerical simulation analysis software, as shown in Figure 4.The model is …
The surrounding rock stability classification of coal roadway is supposed to be based on the characteristics of sedimentary rock (and local igneous rock) in coal mine, which requires clear physical meaning of evaluation index, easy access to parameters, simple classification method, and strong practicability.
NIOSH researchers are investigating potential rock dust application and mitigation techniques to determine if respirable rock dust levels can be lessened. NIOSH …
This study focuses on the occurrence mechanism and monitoring and early warning technology for rockburst in coal mines. Results showed that the prevention and control of rockburst had made significant progress. However, with the increasing mining depth, several unresolved concerns remain challenging.
Super high coal seams used to be mined by protecting the roadway with wide pillar normally 20 ~ 30 m in width. As mining depth and intensity increase, some mines chose to retain 40 ~ 60-m wide pillar for roadway protection, causing tremendous waste of coal resources (Ghasemi et al. 2014; Cao and Zhou 2021; Wang et al. 2020).In …
Panel - A coal mining block that generally comprises one operating unit. Panic bar - A switch, in the shape of a bar, used to cut off power at the machine in case of an emergency. Parting - (1) A small joint in coal or rock; (2) a layer of rock in a coal seam; (3) a side track or turnout in a haulage road.
Coal mines' failures are affected by various factors such as geological and structural parameters (Singh 2005).Thickness, number, depth, and dip angles of seams; …
As coal mining progresses to greater depths, the rate and severity of coal burst hazards have greatly increased, resulting in significant operational and safety challenges. Appropriate rock support design for coal burst-prone roadways requires the understanding of the mechanical characteristics of the support system under impact …
Rock burst is one of the main coal and rock dynamic disasters that affect coal mine production. This kind of burst disaster refers to the sudden, sharp and violent …
A borehole deformation sensor for long-term stress monitoring in coal mine rock based on optical fiber Bragg gratings (FBGs) is presented. The sensor converts borehole deformation into optical fiber strain by using four rings. For each ring, two FBGs are bonded with the ring to measure the borehole deformation, and a reference FBG free …
1. Strong mine earthquakes occurring in the 1 st square of the single goaf in each working face take the largest proportion. In the early stage of coal mining, the frequency of earthquakes is significantly high and most of the mine earthquakes are basically concentrated in the lower hard rock layer. 2.
Burst induction mechanism of rock-coal-bolt (RCB) system. The stress of the roadway surrounding rock is redistributed with thin coal seam mining, forming a stress-enhancing zone from inside to ...
A camera, rock hammer, measuring tape, and a focus on changing conditions can provide a wealth of valuable data to enhance safety by revealing trends that can be linked to geological hazards. ... The roof and floor lithology should be examined because the roof and floor are critical coal mine structural members and this can help detect weak ...
Coal mine waste rock (CMWR) generated in coal mining activities is one of the most significant sources of industrial solid waste. Nearly 4.5 billion tons of CMWR stockpiled in …
In China (the largest coal producer), a dramatic increase in the number of coal mines reporting rock burst hazards has been observed from 32 in 1985 to more than 253 by the end of 2019. Therefore, understanding the mechanism of rock bursts and their monitoring strategies is a very challenging topic to improve mining safety and productivity.