Research on Movement and Deformation of Rock Strata between Coal Seams in Pillar Upward Mining of Left-Over Coal with Numerical Simulation Method. Article Preview. Abstract: Based on the occurrence condition of coal seams and the geological condition on coal seam mining in Coal Mine Group Baijiazhuang, after pillar mining the 8th coal seam was ...
May 23, 2008 These geologic events have shaped Alabama's landscape, and the rock strata that bear testament to these events are either host to significant natural resources—oil, natural gas, and ground water—or, in many cases, are themselves composed of valuable economic commodities, including coal, limestone, sand, gravel, and clay.
Reservoir rock properties of coal measure strata of the Lower Monongahela Group, Greene County (Southwestern Pennsylvania), from methane control and production perspectives C. zgen Karacan CDC/NIOSH Pittsburgh Research Laboratory, Disaster Prevention and Response Branch, 626 Cochrans Mill Road, PO Box 18070, Pittsburgh PA, 15236, United States
coal(rock)pillarincoalminesinChina.erepresentative onesareShietal.[32],whodeducedtheformulaofwater-proof coal (rock) pillar in stope fault based on the com- ... water-proof protective rock stratum of medium hard overlying strata should be taken as 4A according to the
Sep 07, 2021 During the coal mining process, the overlying strata above the stope undergoes intensive movement and large-scale damage, which inevitably cause rock caving and produce fractures. Once these fractures are interconnected, water channels form, which are also referred to as water-flowing fractured zones (Ju et al. 2020 ; Zhang and Shen 2004 ).
In some cases coal strata rest on granite, schist, limestone, conglomerate or other rock unsuitable for soil. Underclay without a coal bed above is common as well as underclay resting on top of coal. The absence of recognizable soils below beds of coal shows the improbability of any type of luxuriant vegetation growing in place and argues for ...
Anthracite: Sometimes also called “hard coal,” anthracite forms from bituminous coal when great pressures developed in folded rock strata during the creation of mountain ranges. This occurs only in limited geographic areas –primarily the Appalachian region of Pennsylvania. Anthracite has the highest energy content of all coals & is
Apr 02, 2013 Longwall mining is the only technically proven and well-established mining method used worldwide for extracting coal from deep mines. In this paper, two-dimensional (2D) continuum finite-element models of longwall panels are developed and analyzed to understand the interaction of hydraulic-powered support with surrounding rock strata (i.e., roof, floor, and coal seam).
DOI: 10.1016/0148-9062 (82)91153-6. Strata mechanics of hydraulic sub-level coal mining. Journal Article Jeremic, M L - Int. J. Rock Mech. Min. Sci.; (United States) Strata mechanics have been studied by monitoring and observing underground mines, and by means of digital and physical models.
Research on Movement and Deformation of Rock Strata between Coal Seams in Pillar Upward Mining of Left-Over Coal with Numerical Simulation Method. Article Preview. Abstract: Based on the occurrence condition of coal seams and the geological condition on coal seam mining in Coal Mine Group Baijiazhuang, after pillar mining the 8th coal seam was ...
Rock strata refers to stacked-up layers of sedimentary rock. Other kinds of rock can have layering in them but the word 'strata' is reserved for sedimentary rocks, rocks composed of individual ...
Sep 24, 2018 In the simulation, and the 6th coal protective layer promoted 320 m. In order to be able to clearly see the distribution of roof structure and stress recovery area in goaf, the rock strata in the upper level drift of the 6th coal protective layer are removed, and only the lower strata structure is retained.
Anthracite: Sometimes also called “hard coal,” anthracite forms from bituminous coal when great pressures developed in folded rock strata during the creation of mountain ranges. This occurs only in limited geographic areas –primarily the Appalachian region of Pennsylvania. Anthracite has the highest energy content of all coals & is
Coal is found under the ground in “coal beds.” It is considered a sedimentary rock and is black or brownish-black in color. It is specifically found in rock strata and appears in layers or veins. These are known as coal beds or coal seams. The hardest form of coal is called, anthracite coal.
@article{osti_5376020, title = {Strata-movement concepts and the hydrogeological impact of underground coal mining. [Effects of subsidence on permeability of rock above longwall]}, author = {Booth, C J}, abstractNote = {A review of mining-engineering concepts and studies in mine hydrology suggests a conceptual model linking the strata deformation, hydraulic property changes, and ground …
DOI: 10.1016/0148-9062 (82)91153-6. Strata mechanics of hydraulic sub-level coal mining. Journal Article Jeremic, M L - Int. J. Rock Mech. Min. Sci.; (United States) Strata mechanics have been studied by monitoring and observing underground mines, and by means of digital and physical models.
Coal measure strata are composed of multiple interbedding strata with different hardnesses. A sudden release of energy that was stored in surrounding rocks of tunnels may induce a rock burst; however, the specific strata in which the energy is accumulated cannot be accurately
overlying rock strata and made great achievements. Qian et al. [19] first put forward the key strata theory, providing a theoretical basis for studying the movement of the overlying hard rock stratum above a coal pillar. Pan [20] and Zhang et al. [21] presented the concept of disturbance quantity in the
Jun 24, 2016 5.2.2. Strain and failure induced by coal mining. Coal mining will cause stress redistribution in surrounding rocks and lead to a series of mechanical effects including rock movement, deformation and failure. For the coal roof and floor, the mining will result in strata …
May 07, 2008 For more than 50 years geologists have recognized that these strata belong to six megasequences (very thick, distinctive sequences of sedimentary rock layers) that can be traced right across North America. 1. The lowermost sedimentary layers in Grand Canyon are the Tapeats Sandstone, belonging to the Sauk Megasequence.
Coal mine methane (CMM) is gas released from coal or surrounding rock strata duringand after coal mining. As such, it is considered a mining hazard, a greenhouse gas, and a possible energy source. CMM as a Mining Hazard. Methane is explosive in concentrations of 5-15% volume in …
overlying rock strata and made great achievements. Qian et al. [19] first put forward the key strata theory, providing a theoretical basis for studying the movement of the overlying hard rock stratum above a coal pillar. Pan [20] and Zhang et al. [21] presented the concept of disturbance quantity in the
In view of the complexity of the rules of rock strata fracture in steeply inclined and extra thick coal seam, the mining method of horizontal section top coal caving was put forward. In this paper, the physical similarity simulation model is established to analyze the movement rules of rock strata. The relationship between the form of rock strata fracture and the thermal infrared radiation is ...
Dec 26, 2013 2.1. Physical Model for Coal Roadway in Soft Rock Strata. The tunnel this paper had chosen is located in Ili forth mine in Xinjiang area. Soft rock strata such as mudstone and sandstone layers with low strength were encountered during the construction of transport tunnel.
The second issue addressed involves the risk assessment of roof rock caving or rock sliding in the tail gate. Another aspect involves the standardisation of local conditions to support the methodology of interpreting shield-strata interactions in the context of work …
rock strata in horizontal section top coal caving mining of SIETCS. Shi et al. [6] analyzed the basic rock strata through the elastic thin plate theory, and obtained the criterion of rock strata fracture. Through the analysis of the mining pressure rules of the working face in steeply
strata deformation, subsidence, retreat mining, and horizontal stress. Integral to each one of these topics and many more is ... lab tests, the relative strength of any coal mine roof rock can be determined. The important rock properties include the uniaxial compressive strength (UCS), the effects of moisture ...
The mechanical models of a thin elastic plate with fixed and simple support ignore the influence of elastic support of coal seam (rock strata) on the roof [9]. The vertical coal seam direction is ...
Dec 19, 2017 The overlying coal rock strata were changed from elastic state to plastic state, the supporting stress reached the peak, and the sinking speed accelerated. The internal cracks of coal rock strata grew, the obvious cracks became noticeable on the surface, and the fluctuations in the EP were higher than before.
Sep 08, 2021 Through this analysis, rock blocks D and E are seen to be the key rock blocks for controlling the strata pressure behavior when the coal pillar comes out of the lower coal mining face. Therefore, the analysis of the stability of the two key rock blocks is the key to understanding the dynamic strata pressure mechanism of the coal pillar in the ...