Key strata characteristics controlling the integrity of deep wells in longwall mining areas

Liang, Shun; Elsworth, Derek; Li, Xuehua; Fu, Xuehai; Sun, Boyang; Yao, Qiangling

doi:10.1016/j.coal.2017.01.012

Cited by 34 publications

(21 citation statements)

References 24 publications

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“…Under the synchronous instability condition of hard roofs with thick strata, reasonable support requirements for the working face at the ultra-thick coal seam are difficult to satisfy by purely elevating the support resistance. Through field observation, physical simulation, and theoretical analysis, Liang [24] obtained three structural models of the overlying strata formed in different periods during the overlying strata fracturing process of a working face (7.0 m in mining height) and proposed a calculation method for the working resistance of hydraulic supports on this working face. Kornowski and Kurzeja [25] conducted a theoretical analysis based on the interactive relation between the immediate roof and the basic roof on a large-mining-height working face and determined the influence characteristics of their interaction on the working resistance of hydraulic supports.…”

Section: State Of the Artmentioning

confidence: 99%

Influence Characteristics of Double-Stratum Hard Roof Movement in a Fully Mechanized Top Coal Caving on the Working Resistance of Supports

Shi¹,

Yin²,

Li³

et al. 2020

JESTR

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In the traditional mechanical models of hard roof, multiple hard rock strata are usually taken as the overall critical stratum to analyze its movement instability characteristics while the mutual effect between two hard rock strata is neglected, so it's difficult for theoretical analysis results to realize the accurate prediction of mine pressure behaviors. The reasonable prediction of mine pressure behaviors on a fully mechanized caving face with multiple hard rock strata is ensured further by considering the geological conditions of the 1307 working face mine in Zhaoxian Coal Mine in the Yonglong Coalfield Mine area in China, a mechanical model of a hard roof structure with high and low strata (double strata) was proposed in this study, and the periodic instability step of the high-and low-level hard roofs and the change laws of support resistance on the working face were also determined. Then, the theoretical calculation results were verified according to field measurement data. Results indicate that fracturing instability does not simultaneously occurred in the high and low strata of the hard roof, as the instability steps are 106 m and 18 m, and the corresponding working resistances of the hydraulic support are 63 MPa and 37 MPa, respectively. Meanwhile, the onsite-measured mine pressure data suggest that the major-cycle cyclic weighting step is approximately 101 m, while the continuous step is approximately 12 m. The minor-cycle cyclic weighting step is within 15-25 m, the continuous step is approximately 2 m, and the peak working resistances of the hydraulic support on the average are 42.3 MPa and 36.8 MPa, respectively, so the on-site monitoring data basically accorded with the theoretical analysis results, thus verifying the scientificity of the constructed mechanical model. This study provides a theoretical reference on the safe mining of the fully mechanized caving face of a multi-stratum hard roof.

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Section: State Of the Artmentioning

confidence: 99%

Influence Characteristics of Double-Stratum Hard Roof Movement in a Fully Mechanized Top Coal Caving on the Working Resistance of Supports

Shi¹,

Yin²,

Li³

et al. 2020

JESTR

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“…As a result, a significant portion of rocks caves to the gob. 28 m high above the #4 seam lays an 8 m thick siltstone, which is the key stratum [44][45][46]. In this stage, bed separation occurs between this rock layer and the 3-1 seam below.…”

Section: Progressive Failure Of Overlying Stratamentioning

confidence: 99%

Numerical Investigation into Evolution of Crack and Stress in Residual Coal Pillars under the Influence of Longwall Mining of the Adjacent Underlying Coal Seam

Wang

et al. 2019

Shock and Vibration

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Longwall mining of the adjacent coal seam with the presence of residual coal pillars overlying the seam can result in abnormal strata pressure and severe overburden failure, which poses a significant threat to mining safety. The threat is mainly manifested in the form of intense coal or rock burst and hazardous interconnection between gobs. This study employed the universal distinct element code (UDEC) to investigate the microscopic failure mechanism of the overlying residual coal pillars under the influence of longwall mining of an adjacent underlying coal seam in Yuanbaowan coal mine, China. Using the Voronoi method, we innovatively visualized the evolution of cracks in residual pillars, revealed the mechanism behind the failure of pillars, and explored the evolution and distribution of abutment stress. Also, strata movement characteristics during underlying panel extraction have been surveyed. Based on the modeling results, effective measures are proposed to ensure safe mining under residual coal pillars. This study might provide a certain reference for safe extraction of multiple seams in Datong Coalfield, China, and also in the central and western Appalachian Basin, United States, where many mining activities are carried out under residual pillars.

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“…Numerical simulation, as a basic method, is widely used to determine the stresses or displacements in underground spaces [21][22], and to analyse the failure mechanism or stability of engineering rock masses [9,[23][24][25][26], to optimise support schemes for roadways [19], and to simulate experimental tests and verify the results thereof [20], etc. In this study, the influence of floor heave on the load-bearing structure in CGC was investigated by utilising FlAC 2D software, especially to assess the effect of water on floor heave.…”

Section: The Influence Of Floor Heave On the Load-bearing Structure Imentioning

confidence: 99%

A Case Study on Large Deformation Failure Mechanism of Coal given Chamber and Invention of a New Wall-Mounted Coal Bunker in Xiashijie Coal Mine with Soft, Swelling Floor Rock

Wang¹,

Xie²,

Jing³

et al. 2017

Preprint

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Serious damage caused by floor heave in the coal given chamber of a vertical coal bunker 12 is one of the challenges faced in underground coal mines. Engineering practice shows that it is 13 more difficult to maintain the coal given chamber (CGC) than a roadway. More importantly, 14repairing the CGC during mining practice will pose major safety risks and reduce production. 15Based on the case of the serious collapse that occurred in the bearing structure of the CGC at the

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Key strata characteristics controlling the integrity of deep wells in longwall mining areas

Cited by 34 publications

References 24 publications

Influence Characteristics of Double-Stratum Hard Roof Movement in a Fully Mechanized Top Coal Caving on the Working Resistance of Supports

Influence Characteristics of Double-Stratum Hard Roof Movement in a Fully Mechanized Top Coal Caving on the Working Resistance of Supports

Numerical Investigation into Evolution of Crack and Stress in Residual Coal Pillars under the Influence of Longwall Mining of the Adjacent Underlying Coal Seam

A Case Study on Large Deformation Failure Mechanism of Coal given Chamber and Invention of a New Wall-Mounted Coal Bunker in Xiashijie Coal Mine with Soft, Swelling Floor Rock

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