Field and numerical investigations of gateroad system failure induced by hard roofs in a longwall top coal caving face

Bai, Qingsheng; Tu, Shihao; Wang, Fangtian

doi:10.1016/j.coal.2017.02.015

Cited by 125 publications

(68 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The long breakages, i.e., the long weighting steps, and their far-reaching effects intensify strata behaviors in the working face. Production practices [7][8][9] have observed frequent incidents in the supports of the working face after mining a thick coal seam with hard roof.…”

Section: Introductionmentioning

confidence: 99%

Reduction of Stress Acting on a Thick, Deep Coal Seam by Protective-Seam Mining

Gao

Xia

et al. 2017

Energies

View full text Add to dashboard Cite

Aiming to reduce the high mining stress observed in large-space roof structures during mechanized mining of thick coal seams, a control technique based on protective-seam mining is proposed. This technique was used to investigate the 8108 working face of the No. 3-5 thick coal seam of the Tashan mine located in the Datong area of Shanxi, China, by means of simulations and field measurements. The numerical simulation revealed that the No. 3-5 coal seam undergoes expansion and deformation, accompanied by stress relief due to the mining of the overlying No. 4 coal seam. The physical simulation demonstrated that mining the protective seam changes the structural characteristics of the overlying strata in advance and reduces the integrity of the roof in the No. 3-5 coal seam. Field measurements showed that the support loads in the 8108 working face are significantly weaker than those in the adjacent 8107 working face, where protective-seam mining was not performed. In the absence of high resistance on the support and distinct periodic weighting characteristics, the rock masses around the 8108 working face and roadway could be easily supported.

show abstract

Section: Introductionmentioning

confidence: 99%

Reduction of Stress Acting on a Thick, Deep Coal Seam by Protective-Seam Mining

Gao

Xia

et al. 2017

Energies

View full text Add to dashboard Cite

show abstract

“…As the working face is close to the burnt rock, the plastic zone of the surrounding rock is increased. The large deformation in working face might be due to an inherent defect of the continuum numerical model, which cannot simulate rock mass detachment or separation, 11 but the continuous falling did occur in the field. At this time, the maximum deformation of roof is about 43 mm, as shown in Figure 7.…”

Section: Numerical Resultsmentioning

confidence: 99%

“…Maximum deformation of roof is 201.6 cm, as shown in Figure 6. The large deformation in working face might be due to an inherent defect of the continuum numerical model, which cannot simulate rock mass detachment or separation, 11 but the continuous falling did occur in the field. Roof failure is a gradual process.…”

Section: Numerical Resultsmentioning

confidence: 99%

The effect of burnt rock on inclined shaft in shallow coal seam and its control technology

Yuan

Liu

Zhu

et al. 2019

Energy Science & Engineering

View full text Add to dashboard Cite

Burnt rock is a geo‐material widely existed in many countries. After the rock mass is burned, the fracture is developed, the structure is destroyed, the integrity and strength are reduced, and a good water storage space is formed in suitable hydration conditions. In this paper, the roof fall characteristics and failure mechanism of inclined shaft in shallow water‐rich burnt rock area (SWRBRA) are analyzed using theoretical analysis, numerical simulation, and field measurement. It is revealed that the main factors causing the instability of surrounding rock on inclined shaft in SWRBRA are the deterioration of structure and integrity after rock mass is burnt, the weakening of surrounding rock strength under the action of fissure water, and the lagging support method. Therefore, the key measure to control the stability of surrounding rock in SWRBRA is to block cracks to eliminate the weakening effect of water and advance reinforcement to improve the surrounding rock strength. Through the comprehensive technologies such as rear roadway reinforcement, filling, and rebuilding artificial false roof and pipe shed advanced support, the effective restoration of the roof fall area in SWRBRA is realized. The surrounding rock fractures were closed, the strength of surrounding rock is improved by means of grouting reinforcement, and the stability control of surrounding rock of inclined shaft in SWRBRA is achieved.

show abstract

“…Jiang et al evaluated and modified the strength of the fractured rock mass and used the numerical software FLAC3D to study the deformation and failure characteristics of the surrounding rocks and the pillar sizes under the geological conditions of fractured rock masses. Bai et al simulated and investigated the damage characteristics of the GSE under hard roof conditions in the field and optimized the pillar width. Basarir et al predicted and analyzed the mining pressure load on the pillar and GSE using a three‐dimensional finite‐difference technique.…”

Section: Introductionmentioning

confidence: 99%

Field and simulation study of the rational coal pillar width in extra‐thick coal seams

Zhao

2019

Energy Science & Engineering

View full text Add to dashboard Cite

The principles of mining pressure in extra‐thick coal seams are different from those of medium‐thick and thick coal seams. Field investigation, laboratory test, and simulation analysis methods were used to study the correlation between the gob‐side entry (GSE) stability and coal pillar width during longwall top coal caving mining in extra‐thick coal seams. The test site is in Datong City, Shanxi Province, China. The mining pressure in N5209 tailgate with coal pillar of 30 m is severe based on the field investigations during the N5209 panel retreat. Global constitutive double‐yield and strain‐softening models were built to study the abutment pressures and plastic failure ranges of coal seams with different thicknesses and coal pillar widths. The simulation results show that the GSE with an 8‐m coal pillar is destressed and minimal GSE deformation occurs. In addition, the abutment stress in the coal pillar decreases with increasing coal seam thickness. The field tests indicate that the GSE with an 8‐m‐wide coal pillar is stable in extra‐thick coal seams. This study provides a reference for the coal pillar design in coal mines with similar geological and mining conditions.

show abstract

Field and numerical investigations of gateroad system failure induced by hard roofs in a longwall top coal caving face

Cited by 125 publications

References 24 publications

Reduction of Stress Acting on a Thick, Deep Coal Seam by Protective-Seam Mining

Reduction of Stress Acting on a Thick, Deep Coal Seam by Protective-Seam Mining

The effect of burnt rock on inclined shaft in shallow coal seam and its control technology

Field and simulation study of the rational coal pillar width in extra‐thick coal seams

Contact Info

Product

Resources

About