Zhang Q.,Liaocheng University |
Zhang X.,Shandong University |
Zhang X.,Huainan Mining Group Co. |
Wang Z.,Liaocheng University |
And 2 more authors.
International Journal of Rock Mechanics and Mining Sciences | Year: 2017
The zonal disintegration phenomena in deep rock mass will appear with the increase of underground engineering depth which is widely different from shallow cavern. In order to reveal the formation mechanism of zonal disintegration, the geomechanical model test and numerical simulation of zonal disintegration are carried out respectively. Taking the deep tunnel of Dingji coal mine in China's Huainan coal mine as engineering background, a 3D geomechanical model test is carried out relying on the high stress 3D loading test system. The zonal disintegration phenomenon is observed, and the oscillation law of displacement and strain are measured. Based on the strain gradient theory and continuum damage mechanics, the zonal disintegration elastic damage-softening model is established. The relationship between rock failure and energy dissipation is analyzed. According to the strain energy density theory, the zonal disintegration energy damage failure criterion based on strain gradient is established. A numerical analysis method for zonal disintegration is proposed, the zonal disintegration calculation program is developed based on a commercial finite element code. The results of numerical simulation and the 3D geomechanical model test are basically consistent. © 2017 Elsevier Ltd
Sang S.,China University of Mining and Technology |
Xu H.,China University of Mining and Technology |
Fang L.,Huainan Mining Group Co |
Li G.,Tiefa Mining Group Co |
Huang H.,China University of Mining and Technology
International Journal of Coal Geology | Year: 2010
This paper summarizes the status of engineering practice, technology and research related to stress relief coalbed methane (CBM) drainage using surface wells in China during the past 10. years. Comments are provided on the theory and technical progress of this method. In high gas mining areas, such as the Huainan, Huaibei and Tiefa mining areas, characterized by heavily sheared coals with relatively low permeability, stress relief CBM surface well drainage has been successfully implemented and has broad acceptance as a CBM exploitation technology. The fundamental theories underpinning stress relief CBM surface well drainage were established in China, and include elements relating to: (1) rock layer deformation theory, vertical zoning and horizontal partitioning, and the change in the stress condition in mining stopes; (2) a theory regarding an Abscission Circle in the development of mining horizontal abscission fracture and vertical broken fracture in overlaying rocks; and (3) the theory of stress relief inducing permeability increase in protected coal seams during mining; and the gas migration-accumulation theory of stress relief CBM surface well drainage. Three kinds of technical drainage modes are described: protected seam surface well drainage in areas influenced by mining represented mainly in the Huainan mining area; gob surface well drainage most prominently in the Tiefa mining areas; and the multipurpose surface well drainage used in the Huaibei mining areas. Serial well allocation in which wells are used for different purposes as extraction and mining proceeds, and well bore configurations and designs suitable for this purpose, are described. The development and utilization of CBM is significant to energy-saving, emission-reduction and to ensure safety in coal production. © 2009 Elsevier B.V.
Luo Y.,State Key Laboratory of Deep Coal Mining and Environment Protection |
Luo Y.,National Engineering Research Center for Coal Gas Control |
Luo Y.,Huainan Mining Group Co.
Journal of Coal Science and Engineering | Year: 2012
Aiming to effectively solve the problem of deep mining with safety and high efficiency, according to geological conditions, production and stress analysis in roadway surrounding rock, experimental studies on roadway supporting of workface 103 under three types of roof conditions with different supporting technologies and parameters were carried out based on the theory of supporting technology of gob-side entry. The results show the supporting of gob-side entry retaining is successful, and the deep surrounding rock is effectively controlled by field monitoring and drilling-hole photos. After stress in surrounding rock of roadways restores stable, the final roadway deformation of surrounding rock of haulage roadway and air-roadway are both about 300 mm; width of gob-side entry is 3.8-4.0 m and average height is 2.0-2.2 m; roadway section is above 8.0 m2, which solves the problems of gob-side entry retaining support strength and safe mining; necessary conditions of mining safety in workface 103 are met. © The Editorial Office of Journal of Coal Science and Engineering (China) and Springer-Verlag Berlin Heidelberg 2012.
Zhou H.,China University of Mining and Technology |
Liu J.,China University of Mining and Technology |
Xue D.,China University of Mining and Technology |
Yi H.,China University of Mining and Technology |
Xue J.,Huainan Mining Group Corporation
International Journal of Mining Science and Technology | Year: 2012
The exploitation of coal bed methane or coal gas is one of the most effective solutions of the problem of coal gas hazard. A better understanding of gas flow in mining-induced cracks plays an important role in comprehensive development and utilization of coal gas as well as prevention of coal gas hazard. This paper presents a case study of gas flow in mining-induced crack network regarding the situation of low permeability of coal seam. A two-dimensional physical model is constructed on the basis of geological background of mining face No. 1122(1) in coal seam No. 11-2, Zhangji Coal Mine, Huainan Mining Group Corporation. The mining-induced stress and cracks in overburden rocks are obtained by simulating an extraction in physical model. An evolution of mining-induced cracks in the process of advancing of coal mining face is characterized and three typical crack networks are taken from digital photos by means of image analysis. Moreover, the numerical software named COMSOL Multiphysics is employed to simulate the process of gas flow in three representative crack networks. Isograms of gas pressure at various times in mining-induced crack networks are plotted, suggesting a shape and dimension of gas accumulation area. © 2012 Published by Elsevier B.V. on behalf of China University of Mining and Technology.
Zhou H.-W.,China University of Mining and Technology |
Zhang T.,China University of Mining and Technology |
Xue D.-J.,China University of Mining and Technology |
Xue J.-H.,Huainan Mining Group Corporation
Meitan Xuebao/Journal of the China Coal Society | Year: 2011
On the basis of geological conditions of coal mining face No. 1122(1) at Zhangji Coal Mine, Huainan Mining Group Corporation, a physical model was constructed. A fractal theory was introduced to characterize distribution and growth of mining-induced cracks in overburden strata. A relation between fractal dimensions of length-number of mining-induced cracks and advancing lengths of coal mining face was investigated. It is indicated that the total number of mining-induced cracks increases with the increasing of advanced lengths of mining face. Moreover, the number of mining-induced cracks increases gradually before breaking of the main key stratum. In addition, the breaking of the main key stratum results in the closing of some cracks in the center of the goaf and the generating of new cracks.
Yao X.-R.,Huainan Vocational and Technical College |
Cheng G.-L.,Huainan Mining Group Co. |
Shi B.-M.,Anhui University of Science and Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2010
According to difficult pore-forming when long drilling through mudstone, structural belt and soft seam, studied return airway 11-2 level -910 m Dingji Coal Mine using FLAC3D computer numerical simulation with fact mechanical parameters of rock mass, calculated drilling stress field, displacement filed and change of plastic failure zone, and concluded that secondary stress elastic-plastic distribution map of drilling was consistent with the theoretical calculation. The distribution of secondary stress elastic-plastic was no longer a ring when side pressure coefficient was not equal 1, the roof and floor radial displacement of drilling was two times of two sides. The stress concentration degree of surrounding rock becomes higher, the displacement of drilling increases, the plastic radius of surrounding rock decreases, and the drilling becomes more instable with the increase of side pressure coefficient. When strengthening area of surrounding rock increases, the secondary stress influence scope of drilling reduces, the radius of plastic area decreases, the radial displacement of drilling decreases, and the drilling is easier to be stable. Based on the theory of drilling creating by solidification technology, the gas extraction drilling instability was controlled effectively in deep surrounding-rock with weak structure crossheading 1421(1) Dingji Coal Mine, and verified with case.
Yuan L.,Huainan Mining Group Co. |
Guo H.,CSIRO |
Li P.,Huainan Mining Group Co. |
Liang Y.-P.,CSIRO |
Liao B.-C.,Huainan Mining Group Co.
Meitan Xuebao/Journal of the China Coal Society | Year: 2013
Coal mine goaf drainage with surface boreholes is increasingly used in coal mines worldwide. However, poor performance of some of these surface gas boreholes is often experienced in terms of the gas concentration, flowrate and borehole stability. In order to improve performance, theoretical studies and field investigations were carried out to develop optimal surface borehole designs based on the experience from Huainan and Australia in recent years. Through the extensive numerical modelling of mining impact in the surrounding strata, and performance of various gas drainage configurations, and by applying the concept of the 3D annular-shaped overlying zone for optimal methane drainage, the trials using large diameter boreholes with diameters of 244.5 mm and 177.8 mm were designed and implemented. The trial results demonstrate that the large diameter boreholes perform significantly better than conventional boreholes in terms of total gas captured, longwall gas control effectiveness, and borehole stability. The total gas captured from a single large borehole can reach 3.167 million m3 with 1.7 million m3 of pure methane, and the borehole productive life is 106 days. The methane concentration in the longwall return gateroad is effectively controlled during the operation of the large boreholes. The trial results also show that the surface borehole located on the longwall return side performes better than that on the intake side. The total gas captured from the return side borehole is 33.7% more than that from the intake side and the methane concentration is 75.3% higher.
Yuan L.,Huainan Mining Group Co.
International Journal of Coal Science and Technology | Year: 2015
The integrated extraction of coal and gas combines coal mining with gas capture. Taking into account the gas deposition and flow conditions in the Chinese coal basins, this paper describes the status of the theory and key technologies of this integrated extraction system, and presents its application and practice in the Shaqu, Zhongxing, Fenghuangshan and Pingmei mines. Areas for further improvements in future studies are discussed, focusing in particular on the fundamentals of the extraction system to make it greener, more scientific, and more advanced in both the exploitation and utilization of coal and the gas in coal. © 2015, The Author(s).
Guo H.,CSIRO |
Yuan L.,Huainan Mining Group Co.
International Journal of Coal Science and Technology | Year: 2015
This paper presents an advanced and integrated research approach to longwall mining-induced strata movement, stress changes, fractures, and gas flow dynamics with actual examples of its application from recent studies for co-extraction of coal and methane development at Huainan Mining Group in China, in a deep and multi-seam mining environment. The advanced approach takes advantage of the latest techniques in Australia for mine scale geotechnical characterisation, field measurement, monitoring and numerical modelling. Key techniques described in this paper include coal mine site 3D geotechnical characterisation methods, surface deep downhole multi-point extensometers and piezometers for overburden displacement and pore pressure measurements during mining, tracer gas tests for goaf gas flow patterns, and advanced numerical modelling codes for coupled coal mine strata, water and gas simulations, and longwall goaf gas flow investigations. This integrated approach has resulted in significant insights into the complex dynamic interaction between strata, groundwater, and gas during mining at Huainan Mining Group in recent years. Based on the findings from the extensive field monitoring and numerical modelling studies, a three-dimensional annular-shaped overlying zone along the perimeter of the longwall panel was identified for optimal methane drainage during mining. © 2015, The Author(s).
Yuan P.,Anhui University of Science and Technology |
Xu Y.,Anhui University of Science and Technology |
Xue J.,Huainan Mining Group Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2016
To investigate the effect of anchorage support on zonal disintegration in deep tunnel excavated by drilling and blasting method, three dimensional physical model experiment under high axial geo-stress and blasting excavation conditions was carried out by deep rock breakage and supporting technique model test apparatus. After blasting excavation and overload in axial direction, both radial tensile strain and radial compressive stress around anchored model tunnel presented a non-monotonic change of distribution with peaks and troughs, which is similar to the model experiment results without the anchorage support. The results indicate a tendency of inducing zonal disintegration in anchorage model tunnel. Compared with the model experiment results without anchorage support, there is no zonal disintegration phenomenon in anchorage positions of model tunnel supported by combination of anchor bolt and anchor cable. Therefore, combination of anchor bolt and anchor cable can transfer and redistribute the stress of surrounding rock. Hence, anchorage support plays an important role in restraining the zonal disintegration. © 2016, Science Press. All right reserved.