Surrounding Rock Control Technology When the Longwall Face Crosses Abandoned Roadways: A Case Study

Jiang, Zhenpeng; Wang, Fangtian; Miao, Kaijun; Cao, Qinghua

doi:10.1155/2021/7867460

Cited by 2 publications

(1 citation statement)

References 8 publications

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“…During the mining period-especially in the vertical distribution with the working face towards the abandoned roadway-the surrounding rock of the abandoned roadway has difficulty withstanding the influence of the working face over the front support pressure and the phenomenon of roof fracture, which are two types of instability. The working face passes through the abandoned roadway with a large span and for a long time, which is detrimental to its safety and stability [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Research on Mechanical Properties and Engineering Applications of Inorganic Cementitious Filling Materials in Coal Mine Abandoned Roadways

Sun,

Li,

et al. 2024

Applied Sciences

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To solve the problems of brittleness, high cost, and the complicated construction process of traditional filling materials for filling abandoned roadways, various aspects of the physical and mechanical properties of the materials were studied using laboratory tests and were applied in coal mines. The research shows that the self-developed inorganic cementitious filling material has the advantages of being low cost, easy to cut and wash, and having good filling performance. A foaming agent is a direct factor in controlling the volume expansion of inorganic cementitious filling materials; the increase in the volume of slurry foaming with the addition of a foaming agent initially showed a large and then a small trend with a foaming agent dosage of 100 g. The increase in the volume of slurry foaming is the largest at 56.28%. The effect of the B material (calcium stearate+ J85 rapid-setting agent) on the foaming time and the number of foaming times of the slurry was significant. Foam stabilizers in the B material make the slurry particles uniformly distributed inside the slurry, while quick-setting agents control the initial and final setting time by affecting the slurry setting speed. The water/cement ratio directly affects the foaming times of the slurry but has little effect on the foaming time and setting speed. When the water/cement ratio is less than 1:2, the slurry foaming effect is poor, and the foaming volume remains unchanged. The strength of the material is significantly affected by the proportion of B material and the amount of blowing agent, and the compressive strength of materials with different compositions and ratios varies greatly. A whole set of systems of new inorganic gelatinized abandoned roadway filling materials was researched and applied in coal mines, achieving good results.

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Section: Introductionmentioning

confidence: 99%

Research on Mechanical Properties and Engineering Applications of Inorganic Cementitious Filling Materials in Coal Mine Abandoned Roadways

Sun,

Li,

et al. 2024

Applied Sciences

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The Stress Evolution of Adjacent Working Faces Passing through an Abandoned Roadway and the Damage Depth of the Floor

Shi

Miao

et al. 2022

Energies

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An advanced break or a vast region of pressurisation may occur when the working face passes through an abandoned roadway, resulting in a roof falling or water inrush. The stress evolution of the working face passing through an abandoned roadway in a coal mine was comprehensively discussed using theoretical analysis, numerical simulation, and field monitoring. In this study, the calculated critical width of the abandoned roadway where the main roof was bound to an advanced break was 5.4 m. Reducing the suspended length of the main roof is beneficial to the stability of the working face’s passage across the abandoned roadway. The maximum abutment stress on the roof occurred at the working face through a semi-abandoned roadway, reaching 44.3 MPa. Subsequently, it decreased sharply until the working face completely passed and returned to the normal level. The damage depths of the floor strata from the field monitoring were 15 and 20 m, which showed that the use of hydraulic fracturing technology combined with floor grouting and hydraulic support for the abandoned roadway was proposed to stabilise the working face for safe mining.

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Surrounding Rock Control Technology When the Longwall Face Crosses Abandoned Roadways: A Case Study

Cited by 2 publications

References 8 publications

Research on Mechanical Properties and Engineering Applications of Inorganic Cementitious Filling Materials in Coal Mine Abandoned Roadways

Research on Mechanical Properties and Engineering Applications of Inorganic Cementitious Filling Materials in Coal Mine Abandoned Roadways

The Stress Evolution of Adjacent Working Faces Passing through an Abandoned Roadway and the Damage Depth of the Floor

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