Results 31 to 40 of about 139,365 (154)

Migration characteristics and disaster reduction and erosion prevention mechanism of thick and hard roof in deep filling mining

open access: yesMeitan kexue jishu
To address the issue of rock burst disasters induced by the fracture of thick-hard roof strata, focuses on deep thick and hard roof. By integrating theoretical analysis, engineering experiments, and field monitoring, the fracture characteristics of thick-
Erhu BAI   +6 more
doaj   +1 more source

Mechanism of Support Optimization and Confined Blasting of Thick and Hard Rock with a Wedge-Structure Immediate Roof: A Case Study

open access: yesGeofluids, 2021
Based on the occurrence conditions of a thick and hard main roof and wedge-structure immediate roof in the Zhuxianzhuang Coal Mine, the fracture characteristics and instability migration law of a thick and hard roof (THR) were examined via physical ...
Tong Zhao   +5 more
doaj   +1 more source

Rock burst mechanism induced by stress anomaly in roof thickness variation zone: a case study

open access: yesGeomatics, Natural Hazards & Risk, 2022
The variation of hard roof thickness is an essential contributor in triggering rock bursts during longwall mining. Case analysis and numerical modeling were used to study the stress and energy characteristics of the coal and rock mass and its fracture ...
Xianxi Bai   +6 more
doaj   +1 more source

Thick-hard strata movement law and multi-dynamic load mechanism in longwall face with ultra-large cutting height

open access: yesMeitan xuebao
Large mining height technology is characterized by high yield, high efficiency, and high recovery rate. It has become the preferred technology for mining thick coal seams in Yushen mining area.
Jiachen WANG   +6 more
doaj   +1 more source

Structural quantification of multi-thick hard roof and strong ground pressure control in large mining height stope: a case study

open access: yesGeomechanics and Geophysics for Geo-Energy and Geo-Resources
The mining of deep large-height longwall faces leads to frequent occurrences of strong ground pressure, at the same time, there are multi-thick hard rock strata in the roof of the longwall face, therefore, it is important to master the fracture ...
Yangbo Lu   +4 more
doaj   +1 more source

Evolution of roof treatment processes from blasting to hydraulic fracturing to prevent rockburst in thick-hard roof coal mines in Xinjiang, China

open access: yesFrontiers in Earth Science
Rockburst prevention poses a major challenge in coal mining, with thick and hard roof strata being the primary cause of rockbursts. To analyze the feasibility and effectiveness of using hydraulic fracturing as an alternative to blasting methods for ...
Kunlun Liu   +8 more
doaj   +1 more source

Deformation and Fracture Mechanisms of Thick Hard Roofs in Upward Mining Coalfaces: A Mechanical Model and Its Validation

open access: yesApplied Sciences
The safety and efficiency of underground coal mining are threatened by thick hard roofs characterized by large overhang areas, problematic spontaneous caving, and high dynamic load upon their breakage.
Wei Zhang   +5 more
doaj   +1 more source

Poultry Housing [PDF]

open access: yes, 1935
PDF pages ...
Cray, R. E., Twitchell, H. P.
core  

Evolution of broken structure of hard thick roof and analysis of impact hazard area

open access: yesMeikuang Anquan
Aiming at the influence of hard and thick roof fracture and structural evolution on the impact of working face, taking the hard and thick roof condition of 63 upper 05 working face in Dongtan Coal Mine as the engineering background, the critical ...
Pengfei LYU   +4 more
doaj   +1 more source

Experiment Study on the Mechanical Behavior and Acoustic Emission Response of Thick and Hard Sandstone Roof in Xinjiang Mining Area

open access: yesAdvances in Civil Engineering
One of the primary threats to coal mine safety production is the sudden extensive fracturing and collapse of thick and hard roof strata. A range of uniaxial compression experiments with acoustic emission (AE) monitoring was performed for studying the ...
Dongdong Qin, Zechao Chang, Ze Xia
doaj   +1 more source

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