A Study of Stability Investigation of Immediate Roof for Extraction of Thick Coal Seam in India

Author(s):  
Aveek Mangal
2011 ◽  
Vol 99-100 ◽  
pp. 207-212 ◽  
Author(s):  
Zhi Qiang Wang ◽  
Han Yang ◽  
Yun Bo Chang ◽  
Peng Wang

Research on the division of the overlying rock roof of stope has great significance. The existing classification method is based on the determination of existing mining height and loose coefficient , and such studies have been proved exist some limitations in the applications of thick coal seam full coal mining. Theoretical analysis and similarity simulation experiments show that during the mining all height at one times in thick coal seam, as the recovery room increase ,the thickness of immediate roof of the overlying strata which fall with the mining increased signifi-cantly, and the structure of the overlying critical layer to stabilize that is the layer of hypogyny basic roof gradually increased. Through theoretical analysis and summarizing similar simulation experiment phenomenon, based on the definition and characteristics of the immediate roof and main roof, with elastic thin mechanics and the key strata theory as the research foundation, doing scientific classification of mining face's roof in all height at one times in thick coal seam, and combined impact of all factors, which influence the breakage and caving of Basic Roof, to estab-lish a scientific judgment in the length of work face and the pressure of basic roof for practical production relations, provide certain theoretical basis.


2013 ◽  
Vol 368-370 ◽  
pp. 1812-1815 ◽  
Author(s):  
Yong Qin Zhang ◽  
Le Le Sun ◽  
Wei Zhong Zhang ◽  
Li Dan Cao

In order to solve the technical problem of gob-side entry retaining in inclined coal seam, combined with the practical mining conditions in a certain mine, this paper adopts the discrete element method, applies numerical simulation to analyze inclined coal seam gob-side entry retaining with three different supporting ways, and studies surrounding rock deformation characteristics of gob-side entry retaining. The research results show that the filling body upper boundary for right side can control the roadway surrounding rock deformation better compared with the boundary is used as the hypotenuse; Meanwhile, the pressure of surrounding rock of coal seam gob-side entry retaining is mainly from the impact of the immediate roof natural fall of the upper goaf tilt and the weight of caving coal gangue and coal seam of immediate roof above; According to the surrounding rock deformation characteristics of coal seam remain gateway along goaf, it is determined to use combined supporting method of concrete filling in roadway sides and anchor wire rope supporting inside the roadways, providing the design basis of gob-side entry retaining in coal seam for the similar geological conditions.


2021 ◽  
Vol 11 (9) ◽  
pp. 4125
Author(s):  
Zhe Xiang ◽  
Nong Zhang ◽  
Zhengzheng Xie ◽  
Feng Guo ◽  
Chenghao Zhang

The higher strength of a hard roof leads to higher coal pressure during coal mining, especially under extra-thick coal seam conditions. This study addresses the hard roof control problem for extra-thick coal seams using the air return roadway 4106 (AR 4106) of the Wenjiapo Coal Mine as a case study. A new surrounding rock control strategy is proposed, which mainly includes 44 m deep-hole pre-splitting blasting for stress releasing and flexible 4-m-long bolt for roof supporting. Based on the new support scheme, field tests were performed. The results show that roadway support failure in traditional scenarios is caused by insufficient bolt length and extensive rotary subsidence of the long cantilever beam of the hard roof. In the new proposed scheme, flexible 4-m-long bolts are shown to effectively restrain the initial expansion deformation of the top coal. The deflection of the rock beam anchored by the roof foundation are improved. Deep-hole pre-splitting blasting effectively reduces the cantilever distance of the “block B” of the voussoir beam structure. The stress environment of the roadway surrounding rock is optimized and anchorage structure damage is inhibited. The results provide insights regarding the safe control of roadway roofs under extra-thick coal seam conditions.


2009 ◽  
Vol 15 (3) ◽  
pp. 299-303 ◽  
Author(s):  
Tian-cai He ◽  
Hai-gui Li ◽  
Hai-jun Zhang

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