fracture development due to coal mining under

Study of the Dynamic Development Law of Overburden ...

2020-4-16 · The average thickness of the main mining 15# coal seam is 5.4 m, the average dip angle is 4°, and the average buried depth is 480 m. The …Modelling of Dynamic Fracture Propagation in Coal …2020-10-13 · 2016 Coal Operators'' Conference The University of Wollongong 10 –12 February 2016 91 MODELLING OF DYNAMIC FRACTURE PROPAGATION IN COAL PILLARS USING FLAC 2D Gaetano Venticinque 1and Jan Nemcik ABSTRACT: For many years the empirical prediction of pillar stability has been the dominant method for pillar design. Now, with the …

Effect of adsorption-induced matrix swelling on coal ...

2021-9-28 · the fracture domain. Due to the small aperture of micro-fractures, coal permeability is particularly sensitive to coal deformation. This makes the coupled gas-solid interaction under in-situ condi-tions more complex (Liu et al., 2011). A number of researchers have conducted laboratory works, proposed theoretical models, and performed numerical .. al mining under Woronora Dam to go ahead after …2020-4-3 · The state government has given the go-ahead for coal mining under Woronora Dam, rejecting appeals by environmental and community groups and a hard copy petition signed by more than 10,700 people.

Characteristics of Stratum Structure and Fracture ...

2021-11-10 · fied mining of thick coal seam. Taking Rujiigou anthracite company in Helanshan coal-field of NingXia Province of China as engineering back-ground, this paper discusses the structure and fracture development law of overburden rock strata in multisection stratified mining of ultrathick coal seam under the condition of shallow buried mining.Energies | Free Full-Text | Ground Fracture Development ...An observatory was established at the Ningtiaota Mine (China) in order to investigate the surface deformation pattern of N00 method workings mining in shallow buried thick coal seams in a windy-sand area. The observatory allows one to measure the coupling between the periodic changes of parameters related to ground subsidence and ground cracks with workings advancement.

Control of Water-Flowing Fracture Development with Solid ...

2021-9-7 · Coal development in China is shifting to its ecologically-vulnerable western regions where the loss of water resources is a major problem with respect to protecting the ecological environment. The results of physical similarity simulation tests showed that the movement and deformation of the strata above the stope with cave mining created a ''domino effect'', which …Size and spatial fractal distributions of coal fracture ...2020-8-1 · Coal permeability is a key issue in CO 2 injection and enhanced coalbed methane (CBM) recovery, and it is determined by the fracture network, which is strongly influenced by mining-induced stress evolutions. For a comprehensive understanding of the size and spatial distribution characteristics of coal fracture networks under different mining-induced stress …

3-D fracture evolution and water migration in fractured ...

2021-11-1 · 3-D fracture evolution in specimen #2 due to in situ fluidized mining-induced stress. a1–a5, b1–b5, and c1–c5 demonstrate fracture closure and growth as the stress stage changes from O to A, A to B, and B to C, respectively. a1 shows the fracture network in stress stage O. a2 and a3 show the closed fractures and remaining fractures as the ...Study of the Fracture Law of Overlying Strata under Water ...2019-5-2 · To accurately detect the development height of the water flowing fractured zone (WFFZ) in the overlying strata of the working face after mining under water and to ensure the safety and reliability of coal mining, the coal seam located under Weishanhu Lake in the Jisan coal mine was used as the experimental system. A similar laboratory simulation and water …

Research on Development Law of Overburden Rock …

fracture. The development area in thick coal seam mining area is in the shape of "V" type, which i. s consistent with the roof and . overburden rock caving, and the movement regularity is strong. The roof does not appear obvious separation and fracture when connecting with opencast coal mining, shallow level. ) 2) 3)Study of the Fracture Law of Overlying Strata under …2019-7-30 · fracture water to flow from the fractured strata into the gob and working face. 2.2. Fracture Expansion Criterion. Due to the interaction of seepage pressure and coal seam mining under water, the strata will fracture and form a fracture zone that utilizes existing holes in the strata, which causes the strata to shear

Fracture Development at Laminated Floor Layers Under ...

Request PDF | Fracture Development at Laminated Floor Layers Under Longwall Face in Deep Coal Mining | The increment of stress level and fracture depth in …Fracture development and fractal characteristics of ...2021-2-2 · The purpose of this paper is to provide scientific basis for the stability evaluation of overburden rock of repeated mining goaf under the expressway. The objectives of the present study are to reveal the development of overburden rock fractures under repeated mining and to identify the fractal characteristics of the overburden rock fractures. The results show that (1) …

Fracture Development at Laminated Floor Layers Under ...

2020-5-16 · The increment of stress level and fracture depth in deep longwall mining can cause groundwater inrush accidents frequently, and it is essential to study the characteristics of fracture development around laminated rock layers at the floor. This can help to understand the mechanism of groundwater inrush events and to reduce the potential risk. According to the …(PDF) Closure effect of mining induced fractures under ...Nevertheless, the mechanism of fracture development and seepage channel or pathway control in the key aquiclude strata (KAS) in backfill coal mining under fluid–solid coupling have …

Development of the fracture zone water flow level in the ...

2019-3-26 · Free-water level calculations in fracture zones are usually performed using the empirical formula recommended in Regulations of Buildings, Water, Railway and Main Well Lane Leaving Coal Pillar and Press Coal Mining (State Bureau of the Coal Industry 2017).The formula applies to coal seams that can be mined in single layers of between about 1 and 3 m thick, …Background review - Subsidence from coal mining …2021-10-3 · Background review: subsidence from coal mining activities Major underground coal mining in Australia mainly occurs in the coal basins of New South Wales and Queensland. Longwall is currently the most common method of underground coal mining in Australia, as it is safer and more efficient in extracting coal than other extraction techniques.

The Law of Fracture Evolution of Overlying Strata and …

2021-8-12 · Research Article The Law of Fracture Evolution of Overlying Strata and Gas Emission in Goaf under the Influence of Mining Cheng Cheng,1 Xiaoyu Cheng,1,2 Rui Yu,3 Wenping Yue,4 and Chao Liu1 1Xi ''an University of Science and Technology, Xian 710054, China 2China Coal Energy Research Institute Co., Ltd., Xi''an 710054, China 3China Coal Huajin Group Co., …Characteristics of Stratum Structure and Fracture ...2021-11-10 · fied mining of thick coal seam. Taking Rujiigou anthracite company in Helanshan coal-field of NingXia Province of China as engineering back-ground, this paper discusses the structure and fracture development law of overburden rock strata in multisection stratified mining of ultrathick coal seam under the condition of shallow buried mining.

Temporal and spatial evolution characteristics of fracture ...

Under the same coal measure stratum condition, several similarities in floor failure characteristics were observed between coal seam floor with and without faults during coal seam mining: a. Both the models of floor strata begin to break in high-stress area before mining.Gas-driven rapid fracture propagation under unloading .. troduction. Coal and gas outbursts during coal mining is a violent dislodgement and ejection of coal as a consequence of sudden release, at a working face, of the internal gas and strain energy.1, 2, 3 In some instances, as much as thousands of cubic metres of methane or carbon dioxide and hundreds of tonnes of fragmented coal mass are emitted from a working face over …

Investigation of Fracture Development and Oilfield ...

2021-7-31 · Due to the considerably small content of oil layers, when comparing the production costs and profit recovery, in most cases direct coal seam mining is carried out first, followed by the oil development. In the process of coal mining under the described geological conditions, the overlying strata may collapse, forming cracks and causing air .. fluence of fracture-induced weakening on coal mine ...2016-10-1 · As a result of the strong influence ahead of mining face, the gateroad undergoes significant ground destabilization and deformation. In the case of the gateroad of panel 11050, under the mining influence, deformation increments of floor and ribs are more significant than that of the roof due to the weak properties of coal.

Experimental Study on the Change of the Pore-Fracture ...

2020-12-30 · After a coal mine is abandoned, a large amount of coalbed methane (CBM) resources is still accumulated in the overlying and underlying coal strata. The structure of the coal/rock pore fracture, which is a key element for the development of CBM resources, changes significantly due to the influence of mining. In this study, the pore volume and pore size …Research on Development Law of Overburden Rock …fracture. The development area in thick coal seam mining area is in the shape of "V" type, which i. s consistent with the roof and . overburden rock caving, and the movement regularity is strong. The roof does not appear obvious separation and fracture when connecting with opencast coal mining, shallow level. ) 2) 3)

Experimental Study on the Change of the Pore-Fracture ...

2020-12-30 · After a coal mine is abandoned, a large amount of coalbed methane (CBM) resources is still accumulated in the overlying and underlying coal strata. The structure of the coal/rock pore fracture, which is a key element for the development of CBM resources, changes significantly due to the influence of mining. In this study, the pore volume and pore size …Energies | Free Full-Text | Ground Fracture Development ...An observatory was established at the Ningtiaota Mine (China) in order to investigate the surface deformation pattern of N00 method workings mining in shallow buried thick coal seams in a windy-sand area. The observatory allows one to measure the coupling between the periodic changes of parameters related to ground subsidence and ground cracks with workings advancement.

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Coal has a distinctive blocky texture due to the presence of two roughly perpendicular fracture sets referred to as cleats (Laubach et al., 1998). Cleats form in coal beds during diagenesis and act as pre-existing weaknesses that can influence the location, orientation, and length of faults.STUDY ON EVOLUTION CHARACTERISTICS OF …2020-11-6 · overburden caving characteristics, fracture development degree, connectivity and water permea - bility under the disturbance of multi-horizontal sectional mining in steep coal seams. According to the actual geological conditions and mining methods, the main target of the paper is to show

Study on Development Law of Mining-Induced Slope …

2021-6-4 · The development law of mining cracks in shallow coal seams under gully topography was used as the research base to analyze the development characteristics of mining cracks in the 5-2 coal mining face of Anshan Coal Mine, and the weak strength was established. The basic top force model under the action of the overburden is the "nonuniformly distributed load …Fracture and pore development law of coal under organic .. anic solvent erosion is an efficient method to promote fracture and pore development in coal. However, the law of fracture and pore development in the process of …

Temporal and spatial evolution characteristics of fracture ...

Under the same coal measure stratum condition, several similarities in floor failure characteristics were observed between coal seam floor with and without faults during coal seam mining: a. Both the models of floor strata begin to break in high-stress area before mining.Disaster-Causing Effects of Coal Mining Face under the ...2018-9-10 · Disaster-Causing Effects of Coal Mining Face under the Action of Hard Thick Magmatic Rock ... due to the large thickness, ... test of the coal seam similar materials and then the law of the bed separation and fracture development under the hard and thick magmatic rocks during the mining process is studied and analyzed and

Background review

2021-10-3 · Background review: subsidence from coal mining activities Major underground coal mining in Australia mainly occurs in the coal basins of New South Wales and Queensland. Longwall is currently the most common method of underground coal mining in Australia, as it is safer and more efficient in extracting coal than other extraction techniques.Study of the Dynamic Development Law of Overburden ...2020-4-16 · The average thickness of the main mining 15# coal seam is 5.4 m, the average dip angle is 4°, and the average buried depth is 480 m. The …

Study on the Law of Fracture Evolution under Repeated ...

Mining operations are gradually deepening due to the reduction in more accessible coal resources. At the same time, more and more attention has been paid to the laws of fracture development in the process of mining under various complex conditions.(PDF) Closure effect of mining induced fractures under ...Nevertheless, the mechanism of fracture development and seepage channel or pathway control in the key aquiclude strata (KAS) in backfill coal mining under fluid–solid coupling have …

Height of overburden fracture based on key strata theory ...

2020-1-24 · In this section, development form of fractures in overburden after coal mining was simulated using discrete element software (UDEC). The model was 400 m long and 205 m wide. The mining coal seam was 5 m thick, and each KS was 10 m thick. Located in the central of the model, the working face was 200 m wide velopment of the fracture zone water flow level in the ...2019-3-26 · Free-water level calculations in fracture zones are usually performed using the empirical formula recommended in Regulations of Buildings, Water, Railway and Main Well Lane Leaving Coal Pillar and Press Coal Mining (State Bureau of the Coal Industry 2017).The formula applies to coal seams that can be mined in single layers of between about 1 and 3 m thick, …

Fracture development due to coal mining under ...

The development characteristics of fractures due to coal mining under deep unconformable overlying strata was investigated using the similar model …Pore and fracture development in coal under stress ...Due to the low permeability of coal reservoirs, it is difficult to directly extract CBM, . Coal is a special porous media that exists many random natural fractures. These defects provide a flow path for gas migration. The pore-fracture structure of coal evolves with stress, temperature, hydrology, and their coupling.

The Law of Fracture Evolution of Overlying Strata and …

2021-8-12 · Research Article The Law of Fracture Evolution of Overlying Strata and Gas Emission in Goaf under the Influence of Mining Cheng Cheng,1 Xiaoyu Cheng,1,2 Rui Yu,3 Wenping Yue,4 and Chao Liu1 1Xi ''an University of Science and Technology, Xian 710054, China 2China Coal Energy Research Institute Co., Ltd., Xi''an 710054, China 3China Coal Huajin Group Co., …Disaster-Causing Effects of Coal Mining Face under the ...2018-9-10 · Disaster-Causing Effects of Coal Mining Face under the Action of Hard Thick Magmatic Rock ... due to the large thickness, ... test of the coal seam similar materials and then the law of the bed separation and fracture development under the hard and thick magmatic rocks during the mining process is studied and analyzed and

Fracture and pore development law of coal under organic ...

Organic solvent erosion is an efficient method to promote fracture and pore development in coal. However, the law of fracture and pore development in the process of …Study on Development Law of Mining-Induced Slope …2021-6-4 · The development law of mining cracks in shallow coal seams under gully topography was used as the research base to analyze the development characteristics of mining cracks in the 5-2 coal mining face of Anshan Coal Mine, and the weak strength was established. The basic top force model under the action of the overburden is the "nonuniformly distributed load …

Research on Development Law of Overburden Rock …

fracture. The development area in thick coal seam mining area is in the shape of "V" type, which i. s consistent with the roof and . overburden rock caving, and the movement regularity is strong. The roof does not appear obvious separation and fracture when connecting with opencast coal mining, shallow level. ) 2) 3)Mechanism of Water Inrush from Coal Floor Fracture in ...2014-8-21 · into Connection fracture under the upward vertical pressure in the bottom and the powerful limestone water pressure, finally forming water inrush. In progressive liters of fracture, along with the advancement of coal seam mining, the goaf'' two sides are the compressive stress, the roof is the tensile stress area, there are concentration