Deformation Behavior of Hard Roofs in Solid Backfill Coal Mining Using Physical Models

Zhou, Nan; Zhang, Jixiong; Yan, Hao; Li, Meng

doi:10.3390/en10040557

Cited by 40 publications

(20 citation statements)

References 19 publications

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“…Zhang et al [38] demonstrated that the hard-roof-induced face burst can be reduced effectively by preventing the roof-caving movement through solid backfilling mining method. Zhou and Li et al [39,40] determined the reasonable backfilling ratio to control the hard roof deformation and reduce the mining abutment stress. He et al [41] analyzed the rockburst prevention by cutting the hard roof directionally in advance under mechanical behaviors of the deep-hole directional fracturing of hard roof.…”

Section: Introductionmentioning

confidence: 99%

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

et al. 2019

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Due to the additional abutment stress, interactional hard roof structures (IHRS) affect the normal operation of the coal production system in underground mining. The movement of IHRS may result in security problems, such as the failure of supporting body, large deformation, and even roof caving for nearby openings. According to the physical configuration and loading conditions of IHRS in a simple two-dimensional physical model under the plane stress condition, mining-induced failure criteria were proposed and validated by the mechanical behavior of IHRS in a mechanical analysis model. The results indicate that IHRS, consisting of three interactional parts-the lower key structure, the middle soft interlayer, and the upper key structure-are governed by the additional abutment stress induced by the longwall mining working face. The fracture of the upper key structure in IHRS can be explained as follows: Due to the crushing failure, lower key structure, and middle soft interlayer yield, the action force between the upper and lower key structures vanishes, resulting in fracture of the upper key structure in IHRS. In a field case, when additional abutment stress reaches 7.37 MPa, the energy of 2.35 × 10 5 J is generated by the fracture of the upper key structure in IHRS. Under the same geological and engineering conditions, the energy generated by IHRS is much larger than that generated by a single hard roof. The mining-induced failure criteria are successfully applied in a field case. The in-situ mechanical behavior of the openings nearby IHRS under the mining abutment stress can be clearly explained by the proposed criteria.

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Section: Introductionmentioning

confidence: 99%

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

et al. 2019

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“…Besides, the failure of the coal pillars left during or after mining may cause security issues and ground subsidence [16][17][18][19][20]. The backfill mining method uses filling bodies to replace coal pillars to support the roof to control the movement and deformation of overlying strata, and therefore to reduce the ground subsidence [21][22][23]. Currently, the backfill mining method has been widely employed in longwall mining; however, it is still experiencing limits in applications.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Roof Ground Subsidence While Applying a Continuous Excavation Continuous Backfill Method in Longwall Mining

Zhang

2019

Energies

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Activities of traditional longwall mining will result in ground subsidence and therefore cause issues such as damages to buildings and farmlands, water pollution and loss, and potential ecological and environmental problems in the mining region. With advantages of the longwall backfill mining method, as well as the room and pillar mining method, a continuous excavation and continuous backfill (CECB) method in longwall mining is recommended to effectively control the ground subsidence. In this method, mining roadways (MRs) are initially planned in a panel, and then they are excavated and backfilled in several stages until the whole panel is mined out and backfilled. According to the geologic conditions of an underground coal mine, and the elastic foundation beam theory, a mechanical model was built to study the subsidence of the roof while using this new mining method. In addition, methods to calculate roof subsidence in various stages in CECB were also provided. The mechanical parameters of backfilling materials, which were used in the theoretical calculation and the numerical analysis for mutual check, were defined through analyzing the stability conditions of the coal pillars and the filling bodies. The control effect for the ground subsidence of using the newly proposed mining method was analyzed based on both simulation results and site monitoring results, including the ground subsidence, horizontal displacement, tilt, curvature and horizontal strain. This research could provide suggestions to effectively control ground subsidence for a mine site with similar geologic conditions.

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“…Miao et al developed a comprehensive mechanized filling coal mining technology which could control the movement of rock stratum and surface subsidence by controlling the backfill rate in goaf [6][7][8][9]. Based on the systematic study of the compaction of waste rock backfilling materials and time correlation, Zhang et al [10][11][12][13][14][15][16] presented an equivalent height model for analyzing the law of mining pressure by filling the goaf with waste rocks. He also obtained the supporting strength in fully mechanized mining and the correction coefficient of filling mining with traditional fully mechanized support strength.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Backfilling Materials on the Deformation of Coal and Rock Strata Containing Multiple Goaf: A Numerical Study

Feng

Zhang

2018

Minerals

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Backfilling mining is thought to play a significant role in controlling the deformation of coal and rock strata and the distribution of underground pressure. This study presents a numerical investigation of the influence of the strength of backfilling materials (BMS) on the deformation of coal and rock strata consisting of multiple goaf during excavation using the backfill mining method. In this study, a numerical three-dimensional fast Lagrangian analysis of continua (FLAC 3D) model was constructed to explore the relationship among the BMS, the displacement of coal and rock strata, and the distribution of underground pressure based on the geological conditions of a mining panel of the Hengda coal mine in the City of Fuxin, China. The numerical results suggest that as the BMS increase, the supporting ability of backfilling materials in goaf becomes stronger. At the same time, when the displacement of coal and rock strata decrease, the pressure on the surrounding rocks decreases and the pressure on the overlying stratum increases. However, the effect of BMS on the coal and rock strata has a limit. When the BMS equals and/or exceeds that of coal, the influence is not obvious. In addition, the displacement and underground pressure in the surrounding goaf are also affected, but in a relatively gentle way. Moreover, during the process of mining, as the BMS increases, the scope and arch area of the underground pressure in front of working face decrease instead. The higher the BMS is, the more stable the main key stratum is. The ability to resist compressional deformation of backfilling materials plays an important role in controlling the displacement of roof and relieving the underground pressure on the overlying stratum. Thereby, the roof stability in front of the working face is helpful for safety in the production of coal mines.

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Deformation Behavior of Hard Roofs in Solid Backfill Coal Mining Using Physical Models

Cited by 40 publications

References 19 publications

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

Mining-Induced Failure Criteria of Interactional Hard Roof Structures: A Case Study

Characteristics of Roof Ground Subsidence While Applying a Continuous Excavation Continuous Backfill Method in Longwall Mining

The Effect of Backfilling Materials on the Deformation of Coal and Rock Strata Containing Multiple Goaf: A Numerical Study

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