ORCID Profile
0000-0002-1599-5157
Current Organisation
Taiyuan University of Technology
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Publisher: Elsevier BV
Date: 11-2009
Publisher: Elsevier BV
Date: 06-2018
Publisher: Hindawi Limited
Date: 11-02-2021
DOI: 10.1155/2021/8833822
Abstract: The basis of traditional ground pressure and strata control techniques is the key strata theory, wherein the position of the key stratum can easily be determined for coal seams with regular thickness and without goaf. However, in the case of mining ultrathick coal seams underneath goaf, the traditional methods used for the calculation of key stratum position need to be improved in order to account for the additional coal seam thickness and the presence of an upper goaf. This study analyzed the failure height and collapse characteristics of overlying strata during excavation for determining the structure of the failed overlying strata. The results indicate that the intercalation and overlying strata gradually evolve into a large “arch structure” and a small “arch structure” during longwall mining, respectively. A mechanical model of the bearing characteristics of the interlayer key strata structure was established according to the structure of the intercalation rock layer, which is a hinged block structure. The results of the model indicate that the maximum principal stress occurs when the key strata portion of the arch structure bears the overlying load. Consequently, the movement and position of the interlayer key strata can be evaluated throughout the mining process of the ultrathick coal seams underneath goaf. This method was used to determine the position of interlayer key stratum of overlying strata in Xiegou coal mine. And the results agree with that of the engineering practice. The results are significant to determine the key strata position during ultrathick coal seam underneath goaf longwall mining.
Publisher: Hindawi Limited
Date: 11-02-2019
DOI: 10.1155/2019/5171873
Abstract: Interbedded strata and their collapse are vital to mining pressure control for extremely thick coal seam under goaf. To ensure the stability of the support and to avoid roof collapse, some traditional underground pressure theoretical models had been widely used in the control of surrounding rock and the selection of support. However, one of the challenges for extremely thick coal seam under goaf is that the abnormal disasters, such as support crushing and water inrush that were occurring frequently. To solve this problem, the movement characteristics of overburden rocks during the mining of extremely thick coal seam under the conditions of the interlayer thickness of 5 m and 40 m were studied by using the similar simulation experiments, while the numerical simulation experiments were carried out for the interval between coal seams of 15 m and 60 m, respectively. Finally, the structure and mechanical transfer mechanism of overburden in stope under different thickness interbedded strata were analyzed dynamically, and the condition of full-thickness connection between upper goaf and lower goaf and corresponding judgment criteria are obtained. These results can guide future research on the mechanical of extremely thick coal seam under goaf, which can provide a theoretical basis and engineering reference for similar projects.
Publisher: Elsevier BV
Date: 06-1995
Publisher: American Chemical Society (ACS)
Date: 27-01-2018
Publisher: Trans Tech Publications, Ltd.
Date: 12-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.415-417.2275
Abstract: Two mechanisms about electrochemical modification of clay minerals are summarized: one of electroosmotic dewatering and stabilization and the other of cation substitutions, structures and properties change, forming new minerals. The analyses of physicochemical soft rock (PCSR) indicate that physicochemical property of PCSR is dominated by physicochemical property of clay minerals. Therefore, it is possible to indurate PCSR in the coal-mine soft rock roadway with the electrochemical method.
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 05-2014
Publisher: Trans Tech Publications, Ltd.
Date: 11-2011
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.160-162.1659
Abstract: Experimental studies on thermal strain of aerial laminated glasses by virtue of Moire Interferometry were done. The experimental results were as follows: in the U patterns of moire interference fringe, with temperature increasing, the fringes became denser and the thermal strain was augmented. In the V patterns of moire interference fringe, the sequence of the fringe patterns increased is intermediate film layer, external shielding layer and main bearing layer, respectively. The U and V fringe patterns results analyzed by digital image process system indicate that, with temperature increasing, the strain εx decreased. Because the difference of coefficients of thermal expansion of three materials is very large, the thermal strain is generated significantly, and the interlayer thermal shear strain exists in the end and intermediate position of the free boundary of the laminated glass.
Publisher: Elsevier BV
Date: 06-2011
Publisher: Elsevier BV
Date: 09-2014
Publisher: Informa UK Limited
Date: 22-03-2018
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 2011
Publisher: Elsevier BV
Date: 05-2016
Publisher: Hindawi Limited
Date: 25-11-2018
DOI: 10.1155/2018/6871820
Abstract: Because the coal seam is particularly thick and the mining intensity is large, the mining of extremely thick coal seams often causes a wide range of disturbed fractures, which in turn induces the phenomenon of strong underground pressure such as induced support crushing and water inrush. Through theoretical analysis, laboratory similarity simulation test, and other methods, this paper studies the effect of mining thickness on overburden movement and underground pressure characteristics for extremely thick coal seams by sublevel caving with high bottom cutting height. Some conclusions can be drawn as follows: (i) under the “beam-hinged cantilever beam rocks” structure theory, the rock pillar thickness which needs to be controlled increases linearly as a function of mining thickness is achieved, and the reason of increased of support resistance in full-mechanized caving mining in extremely thick seams is explained in the theory (ii) based on the results of the theoretical analysis and the lab simulation tests, the law of the abutment pressure peak is inverse to the full-seam mining thickness, and the distance between abutment peak and working face is proportional to the full-seam mining thickness, that is to say that the damage range of overlying strata increased (iii) there are three working states of loading support in extrathick coal seams, such as normal circumstance, lower main roof pressure, and higher main roof pressure, meanwhile these states keep changing (iv) under the guarantee of stope safety conditions, due to lower support strength, it will benefit the special thick seam top-coal caving under normal circumstance (v) increasing the supporting strength can balance the impact loading under the lower main roof pressure, guaranteeing valid support for roof strata (vi) by releasing high pressure, due to lower production, lower recovery rate of coal and other measures guarantee the stability of the stope support in the case of the higher main roof pressure.
Publisher: Trans Tech Publications, Ltd.
Date: 2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.433-440.2071
Abstract: The environmental problems about destruction and pollution of water resource, destruction and occupation of land resource, and air pollution in coal mining was described. Green mining technology in terms of the solution in environmental problems caused by coal mining was introduced. The main content of green mining includes reduction of rock waste, simultaneous extraction of coal and coal-bed methane, water-preservation in mining areas, coal mining to retard surface subsidence, and underground coal gasification. Green mining harmonizing with resources and environment is the fundamental method to solve environmental problems caused by coal mining. In order to develop green mining technology, the economic evaluation of green mining and the establishment of relevant laws need to be further strengthened.
Publisher: IEEE
Date: 02-2011
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 09-2014
Publisher: Hindawi Limited
Date: 11-02-2021
DOI: 10.1155/2021/6661581
Abstract: The study of the effects of mining height on overlying strata movement and underground pressure characteristics during extremely thick coal seam fully mechanized sublevel caving mining is very important for choosing the reasonable mining height and the support. Based on the geological setting and mining conditions at the Xiegou Coal Mine, the results of the physical simulation test and the numerical simulation technology will be used. Some conclusions can be drawn as follows: (1) With the mining height increase, the top coal gradually converted from tensile failure to shear damage, and the coal wall gradually transformed from shear failure to tensile damage. (2) When the mining height is 7.5 m, the full-seam collapse distance, the immediate first weighting interval, and the main roof first weighting length are shorter than that when the mining height is 4m, and the periodic weighting length for the two mining heights is almost the same. (3) With mining height increase, the initial mining stage and the transition stage become shorter, and the production rates become better. (4) The law of the abutment pressure peak and the sphere of influence increase slightly, and the working resistance of support needed to be strengthened. (5) The subsidence quantity of the top coal in the control area increases along with the mining height in a quadratic polynomial way but decreases along with the initial supporting force in a negative logarithmic rule. (6) After assigning the subsidence, the regression relation between the initial supporting force and the mining height is a quadratic polynomial.
Publisher: IEEE
Date: 02-2011
Publisher: Springer Science and Business Media LLC
Date: 26-07-2018
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