scholarly journals Influence of Spatial Relationships between Key Strata on the Height of Mining-Induced Fracture Zone: A Case Study of Thick Coal Seam Mining

Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 102 ◽  
Author(s):  
Peng Li ◽  
Xufeng Wang ◽  
Wenhao Cao ◽  
Dongsheng Zhang ◽  
Dongdong Qin ◽  
...  
Keyword(s):  
Coal Seam ◽  
Fracture Zone ◽  
Spatial Relationships ◽  
Thick Coal Seam ◽  
Key Strata ◽  
Seam Mining

scholarly journals Formation Mechanism and Reduction Technology of Mining-Induced Fissures in Shallow Thick Coal Seam Mining

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Jianwei Li ◽  
Changyou Liu
Keyword(s):  
Coal Seam ◽  
Formation Mechanism ◽  
Surface Mining ◽  
Morphological Development ◽  
Geological Condition ◽  
Thick Coal Seam ◽  
Key Strata ◽  
Shallow Coal Seam ◽  
Seam Mining ◽  
Step Type

Surface mining-induced fissures formed in shallow coal seam mining have serious impact on safety mining and water resources protection. This paper proposes a novel approach to study the formation mechanism and dynamic development of surface mining-induced fissures in shallow coal seam mining. This approach combines field tests, theoretical analysis, and numerical simulations based on the geological condition of shallow coal seam mining in Chuancao Gedan Coal Mine. Two typical surface mining-induced fissures, step-type fissures and collapse-type fissures, are generated in shallow coal seam mining. The fissures with large vertical throw or horizontal opening severely impact water resource protection and surface ecological environment. Surface mining-induced fissures are generated periodically and changed dynamically with the advancing of working face. The vertical throw and horizontal opening of surface fissures are changed dynamically with the movement of loading key strata. The movement forms of loading key strata determine the morphological development of surface fissures. Downward sliding movement of broken rocks causes step-type fissures, while downward rotation movement leads to collapse-type fissures. The degree of the downward sliding and rotation of broken rocks determines the vertical throw and horizontal opening of surface fissures. This paper proposes mining technologies to reduce damaging ground fissures in shallow coal seam mining and analyzes their control effects.

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.

scholarly journals Case study on the mining‐induced stress evolution of an extra‐thick coal seam under hard roof conditions

2020 ◽  
Vol 8 (9) ◽  
pp. 3174-3185 ◽  
Author(s):  
Cong Li ◽  
Heping Xie ◽  
Mingzhong Gao ◽  
Jing Xie ◽  
Guangdi Deng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Stress Evolution ◽  
Thick Coal Seam ◽  
Hard Roof ◽  
Induced Stress
Sign in / Sign up

Export Citation Format

Share Document