scholarly journals Pillar size optimization design of isolated island panel gob-side entry driving in deep inclined coal seam—case study of Pingmei No. 6 coal seam

2018 ◽  
Vol 15 (3) ◽  
pp. 816-828 ◽  
Author(s):  
Shuai Zhang ◽  
Xufeng Wang ◽  
Gangwei Fan ◽  
Dongsheng Zhang ◽  
Cui Jianbin
Keyword(s):  
Coal Seam ◽  
Optimization Design ◽  
Size Optimization ◽  
Pillar Size ◽  
Island Panel

scholarly journals Cooperative Control Mechanism of Long Flexible Bolts and Blasting Pressure Relief in Hard Roof Roadways of Extra-Thick Coal Seams: A Case Study

2021 ◽  
Vol 11 (9) ◽  
pp. 4125
Author(s):  
Zhe Xiang ◽  
Nong Zhang ◽  
Zhengzheng Xie ◽  
Feng Guo ◽  
Chenghao Zhang
Keyword(s):  
Coal Seam ◽  
Cooperative Control ◽  
Field Tests ◽  
Surrounding Rock ◽  
Deep Hole ◽  
Coal Seams ◽  
Thick Coal Seam ◽  
Structure Damage ◽  
Hard Roof

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.

Informal and Nonformal Adult Learning in the Coal Seam Gas Protests: Mobilizing Practices and Building an Environmental Justice Movement for Change

2021 ◽  
pp. 074171362110053
Author(s):  
Tracey Ollis
Keyword(s):  
Adult Learning ◽  
Coal Seam ◽  
Environmental Justice ◽  
Water Supply ◽  
Case Study Research ◽  
Coal Seam Gas ◽  
The Public ◽  
Theory Of Practice ◽  
The Earth

This case study research examines informal adult learning in the Lock the Gate Alliance, a campaign against mining for coal seam gas in Central Gippsland, Australia. In the field of the campaign, circumstantial activists learn to think critically about the environment, they learn informally and incidentally, through socialization with experienced activists from and through nonformal workshops provided by the Environmental Nongovernment Organization Friends of the Earth. This article uses Bourdieu’s “theory of practice,” to explore the mobilization of activists within the Lock the Gate Alliance field and the practices which generate knowledge and facilitate adult learning. These practices have enabled a diverse movement to educate the public and citizenry about the serious threat fracking poses to the environment, to their land and water supply. The movements successful practices have won a landmark moratorium on fracking for coal seam gas in the State of Victoria.

scholarly journals Comprehensive technical support for safe mining in ultra-close coal seams: A case study

2021 ◽  
pp. 014459872110093
Author(s):  
Wei Zhang ◽  
Jiawei Guo ◽  
Kaidi Xie ◽  
Jinming Wang ◽  
Liang Chen ◽  
...  
Keyword(s):  
Coal Seam ◽  
Technical Support ◽  
Surrounding Rock ◽  
Coal Seams ◽  
Deformation Control ◽  
Hard Roof ◽  
Working Face ◽  
Close Coal Seams ◽  
Safe Mining

In order to mine the coal seam under super-thick hard roof, improve the utilization rate of resources and prolong the remaining service life of the mine, a case study of the Gaozhuang Coal Mine in the Zaozhuang Mining Area has been performed in this paper. Based on the specific mining geological conditions of ultra-close coal seams (#3up and #3low coal seams), their joint systematic analysis has been performed, with the focus made in the following three aspects: (i) prevention of rock burst under super-thick hard roof, (ii) deformation control of surrounding rock of roadways in the lower coal seam, and (iii) fire prevention in the goaf of working face. Given the strong bursting tendency observed in upper coal seam and lower coal seam, the technology of preventing rock burst under super-thick hard roof was proposed, which involved setting of narrow section coal pillars to protect roadways and interleaving layout of working faces. The specific supporting scheme of surrounding rock of roadways in the #3low1101 working face was determined, and the grouting reinforcement method of local fractured zones through Marithan was further proposed, to ensure the deformation control of surrounding rock of roadways in lower coal seams. The proposed fire prevention technology envisaged goaf grouting and spraying to plug leaks, which reduced the hazard of spontaneous combustion of residual coals in mined ultra-close coal seams. The technical and economic improvements with a direct economic benefit of 5.55 million yuan were achieved by the application of the proposed comprehensive technical support. The research results obtained provide a theoretical guidance and technical support of safe mining strategies of close coal seams in other mining areas.

The Kinematics Analysis and Study on Triangular Elbow Servo Press

2011 ◽  
Vol 121-126 ◽  
pp. 1636-1640
Author(s):  
Ying Qiu ◽  
Wei Min Li ◽  
Zhi Wei
Keyword(s):  
Optimization Design ◽  
Research Field ◽  
Transmission Mechanism ◽  
Kinematics Analysis ◽  
Servo Motor ◽  
Forming Process ◽  
Servo Press ◽  
Heavy Haul ◽  
Slider Motion

Servo presses are widely used in high-precision, complicated forming process fields and promoted around the world in recent years. It is the trend of forging machinery for its servo motor-based digital heavy haul driven technology. At present, it becomes the hot research field. The structure characteristics of triangular elbow servo press were firstly introduced in the paper. And then the kinematics mathematical model of triangular elbow transmission mechanism was deduced and given. Based on it, this paper provides the slider kinematics analysis by Matlab. The slider motion law under various parameters can be analyzed and compared. The results would be useful reference for optimization design of transmission mechanism. The case study provides more visual and reliable decision basis for designer.

Evaluation of social externalities in regional communities affected by coal seam gas projects: A case study from Southeast Queensland

2017 ◽  
Vol 131 ◽  
pp. 300-311 ◽  
Author(s):  
Anna (Anya) Phelan ◽  
Les Dawes ◽  
Robert Costanza ◽  
Ida Kubiszewski
Keyword(s):  
Coal Seam ◽  
Coal Seam Gas ◽  
Southeast Queensland
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