Mechanism of Water Inrush from Coal Floor Fracture in ...

The development characteristics of fractures due to coal mining under deep unconformable overlying strata was investigated using the similar model test and DEM numerical simulation,and taking No.3 ...

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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.

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 conditions, a series of laboratory ...

Analysis of local fractures and crack growth in coal seams ...

2006-1-15 · An analysis is performed for the effect that a growing rock pressure in stress concentration zones has on development of local fractures of coal due to stratal water, and on closing-up of bedding joints, which confines this process. It is shown that all of unstable cracks in a seam grow dynamically until the related bedding crack closing-up.

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 distribution (PSD) of six coals (three ...

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.

Factors – Coal – Mining Science and Technology

The strength and elastic module of the coal seam influence the fracture mechanics of an outburst. Stored elastic strain energy is released, and the failure is usually brittle indicating that the strain energy is not being used to distort the strata and a large …

Evolution characteristics of mining-induced fracture and ...

Evolution characteristics of mining-induced fracture and abutment stress under high-position hard thick stratum and its effect on gas migration ... WANG Pu, ZHENG Pengqiang, WU Quanlin, State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology, Shandong University ...

The Law of Fracture Evolution of Overlying Strata and Gas ...

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., Ltd., Hejin 043300, …

Investigation of the evolution and control of fractures in ...

2021-3-31 · The Changcun coal mine is designed to adopt inclined shaft development. The direct roof of the roadway is sandstone with a thickness of 0.1–9.5 m. The sandstone [ 36 ] contains water, the lower part is loose and collapses easily, and the upper part is dense and hard.

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 deep longwall mining can cause ...

Evolution of unloading damage and distribution of ...

2019-1-18 · between the cracks under the normal mining and repeated mining is analyzed. Optimize and determine the mining area of the mining stope and its extraction technology, and then carry out the efficient mining and utilization of the repeated mining goaf,and provide decision making basis for - the accurate control of gas. 2.

Numerical simulation of spatial distributions of mining ...

2018-10-1 · Underground coal mining in highly gassy coal seams can cause stress redistribution and large-scale movement of the strata, which result in the development of fracture field. The complex fracture fields increase stratum permeability and thereby provide the major channels for gas migration and drainage (Qian and Xu, 1998, Xie et al., 2011 ...

Development of HF in High Stress Conditions in ...

2019-1-18 · Black, D J and Aziz, N I, 2008. Development of hydraulic fracturing in high stress conditions in Australian underground coal mines, in Proceedings of the 16th Coal Congress of Turkey, Chamber of Mining Engineers of Turkey, Zonguldak, Turkey, 26-28 May, pp 171-184

THERMAL INFRARED CHARACTERISTICS OF ROCK …

2020-11-6 · 10.8 km long from east to west, 0.7-2.7 km wide from north to south. The area of coal mine was about 20.3 km2. The designed production capacity was 6 million tons per year. The north mining area of Wudong Coal Mine was located in the north side of the Badaowan syncline, and the basic structure was a monoclinic structure inclined to the north.

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

Application of MIKE SHE to study the impact of coal mining ...

2017-12-21 · Due to the development of fractures under the action of coal mining, the hydraulic connections between different water sources are enhanced, causing the increase of Fenhe River''s seepage. Under the natural state, baseflow excretes in form of evaporation and efflux [46, 47]. However, during the coal mining period, a large amount of groundwater ...

Modelling of Dynamic Fracture Propagation in Coal Pillars ...

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 advanced numerical modelling of dynamic fracture propagation…

Thermally

2019-3-10 · EAThermally - Induced Fractures in Coal, Balingian Province, Sarawak, Malaysia* . Yasir Ali Ibrahim1 and Eswaran Padmanabhan 2. Search and Discovery Article #80674 (2019)** Posted March 11, 2019 *Adapted from extended abstract prepared in conjunction with oral presentation given at 2018 International Conference and Exhibition, Cape Town, South Africa,

Hydraulic Fracturing in Underground Coal Mines

2019-1-18 · Keywords: Hydraulic fracturing, mine gas drainage, borehole casing, cementing and slotting. 1. INTRODUCTION . Hydraulic fracturing (HF) is a method of stimulating gas production through the injection of fluid under pressure into the coal formation to create fractures.

Study on Development Law of Mining-Induced Slope Fracture ...

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 beam” structure model.

An Estimation of the Height of Fracture Zone In Longwall ...

2012-6-24 · Longwall mining is one of the most widely used methods in underground coal extraction. One of the most important advantages of this method is the automated form of underground coal mining characterized by high recovery and extraction rates. The main objective of the coal mining is to economically extract coal and safely remove them from the ground.

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) the separation fracture ...

Development of 3‐D Curved Fracture Swarms in Shale Rock ...

2021-4-11 · Development of 3-D fracture swarms due to internal fluid generation in shale involves five basic fracture interaction modes, that is, simultaneous apart growth (mode-I), differential growth (mode-II), crossing (mode-III), arresting (mode-IV), and coalescence (mode-V).

Optimization of mining parameters for coal mining under ...

【Abstract】 <>Safe coal mining is closely related to appropriate mining parameters due to that the key mining parameters directly decide the failure extent in overlying stratums this study,taking the geological conditions of 3# coal seam in Shizuishan mine in Ningxia,China as the engineering background(a huge discontinuity plane exists between the quaternary loose soil and the coal ...

A study on coal mining under large reservoir areas ...

2008-5-9 · A study on coal mining under large reservoir areas A study on coal mining under large reservoir areas Wu, Xiong; Wang, Xiao-Gang; Jiang, Xiao-Wei; Duan, Qing-Wei; Sun, Yan-Dong; Tian, Hong; Jia, Zhi-Xin 2008-05-09 00:00:00 Environ Geol (2009) 57:675–683 DOI 10.1007/s00254-008-1346-5 O R I G IN AL ARTI CL E Xiong Wu Æ Xiao-Gang Wang Æ Xiao-Wei Jiang Æ Qing-Wei Duan Æ …

Bed separation backfill to reduce surface cracking due to ...

2019-8-21 · 1. Introduction. After coal mining, the surface above a goaf generally experiences continuous deformation, such as continuous subsidence, horizontal movement and tilt [1–6].Under some special geological and mining conditions, the surface may have discontinuous deformation, such as surface cracking, surface step subsidence and collapse pits [7–10].

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 rock mass stress–strain …

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

Prediction of Fractures in Coal Seams with Multi-component ...

2019-4-24 · To ensure coal mining safety, high-accuracy three-dimensional seismic technology can be applied to determine the distribution of the coal seam and extract information on fracture development …

Coal 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.

Research on Development Law of Overburden Rock …

Research on Development Law of Overburden Rock Fracture in Steeply Inclined and Very Thick Coal Seam Mining Weimin Cheng1, a, Lulu Sun1, b 1 Key Laboratory of Ministry of Education for Mine Disaster Prevention and Control, Shandong University of …

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