Grout injection into bed separation to control surface subsidence during longwall mining under villages: case study of Liudian coal mine, China

Xuan, Dayang; Xu, Jialin

doi:10.1007/s11069-014-1113-8

Cited by 54 publications

(40 citation statements)

References 18 publications

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“…The injection ratio, which was determined as 25.7% for the overall longwall, is slightly less than that for the longwall using the traditional technique of injection during mining. 2 However, the actual ratio of the injected areas of boreholes #1-3 should be larger if the area of borehole #4 (where injection was not applied) is not taken into consideration. Assuming that the grout injected into borehole #3 spread 200 m from the borehole, 2 the injection ratio is estimated to be 32.2% around boreholes #1-3 (from the start of the longwall to 553.1 m away), which is similar to the values obtained using traditional methods.…”

Section: Effectiveness Of the Proposed Methodsmentioning

confidence: 99%

“…The injection of grout into this zone begins when the longwall face approaches the borehole and continues as the face advances until the required injection pressure and volume are achieved. 2 Because of the high injection pressure and large injection volume (generally up to 40% of the mined-out space), the main injection horizon (i.e., the horizon containing 90% of the total fill) will occur between the bottom of the injection borehole and the overlying key stratum. 3 However, if the target horizon of the injection is the gob area, the grouting is generally implemented by drilling boreholes into the mined-out areas following the extraction.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…A typical injection system and process are described in Ref. 2 During injection, the volumes of grout and corresponding dry fly ash injected were recorded daily.…”

Section: Trial Designmentioning

confidence: 99%

“…The former mode is used for active longwall panels and is the best injection technique for controlling surface subsidence; thus, it is the most commonly used mode. 2 However, this injection mode cannot be combined with gas drainage in the same borehole because the downward grout flow will block the upward flow of the drained gas and vice versa. The other mode-injection following mining, which is for abandoned longwalls only-allows effective drainage of overburden seam gas, but is generally applied as a remedial measure for ground stabilization (i.e., mitigation of further residual subsidence).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A shared borehole approach for coal-bed methane drainage and ground stabilization with grouting

Xuan

Wang

2016

International Journal of Rock Mechanics and Mining Sciences

Self Cite

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Section: Effectiveness Of the Proposed Methodsmentioning

confidence: 99%

Section: Theoretical Backgroundmentioning

confidence: 99%

“…A typical injection system and process are described in Ref. 2 During injection, the volumes of grout and corresponding dry fly ash injected were recorded daily.…”

Section: Trial Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A shared borehole approach for coal-bed methane drainage and ground stabilization with grouting

Xuan

Wang

2016

International Journal of Rock Mechanics and Mining Sciences

Self Cite

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“…This can cause mined-out areas to collapse instantaneously, directly threatening overall slope stability and the lives of the miners. In recent years, extensive research has been carried out into mined-out areas under slopes with regard to such factors as the influence of the mined-out area on slope stability, the critical safety thickness of the roof of the mined-out area, and treatment methods for the mined-out area [7][8][9][10][11][12][13]. Hoek proposed that failure would take the form of progressive caving and that steeply dipping slopes are prone to topple when an inclined ore body is mined out; he proposed a limit equilibrium method for slope stability analysis [14].…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Critical Safety Thickness for Pretreatment of Mined‐Out Areas Underlying the Final Slopes of Open‐Pit Mines and the Effects of Treatment

Tao

Zhu

et al. 2018

Shock and Vibration

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Where a mined-out area underlies a slope, it is a direct threat to slope safety and stability. This is of particular concern where a mined-out area underlies the slope of an open-pit mine, and it has a serious impact on the design and safety measures used for the mine. If a mined-out area underlying the final slope of an open-pit mine is not treated adequately and at the appropriate time, it may cause the slip failure of the final slope during the service life of the mine, posing a serious threat to the safety of personnel and equipment during the stripping phase. In light of the potential for such problems, this paper analyzes the instability mode and failure characteristics of an open-pit slope near a mined-out area in China using geological field survey and the polar stereographic projection method. The scale span method, in combination with engineering analogy and consideration of openpit mining technology, is then used to determine the critical safety thickness at which pretreatment of mined-out areas should be carried out. A pretreatment process to infill the mined-out area during construction of open-pit mine steps is put forward, and its effects on slope stability and reliability are comprehensively evaluated. The results show that circular sliding is the most appropriate instability mode for a slope near a mined-out area. The failure initiates through breakage in the roof of the mined-out area, which induces subduction sliding of the free face of the slope at the left boundary of the mined-out area and subsequent failure of the entire regional slope. Comprehensive analysis methods are used to determine that the critical safety thickness at which a mined-out area under the final open-pit slope should be pretreated is 24 m. The recommended treatment countermeasure is to transfer filling slurry into the mined-out area through drilling holes in benches. This can satisfy the stability and reliability requirements for the slope under different working conditions.

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A novel short‐wall caving zone backfilling technique for controlling mining subsidence

Liu

Zhu

et al. 2019

Energy Science & Engineering

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Mining‐induced voids are the main circulation pathways for underground fluids such as water and coalbed methane. The collapse of these voids transmits to the ground surface, resulting in subsidence and building collapse. Accordingly, effective and feasible solutions are needed to control surface subsidence. In this study, a novel technique of void filling in the short‐wall caving zone was proposed to better control surface subsidence in thin coal seam mining. The width of the working face plays a key role in the proposed technique. A maximum surface subsidence value was predicted using numerical simulation and physical simulation experiments with different working face widths. The results indicate that the appropriate working face width should be less than 50 m for the studied coal mine. In this example, the surface subsidence coefficient was less than the standard value for initial damage to rural structures. Both advancing speed and productivity of the working face were achieved using the proposed technique because the filling and mining processes were conducted simultaneously on different faces. The results suggest that surface subsidence during thin coal seam mining could be controlled using the proposed technique. This technique can also help mitigate mining‐induced water inrush and gas leakage disasters by filling voids.

show abstract

Grout injection into bed separation to control surface subsidence during longwall mining under villages: case study of Liudian coal mine, China

Cited by 54 publications

References 18 publications

A shared borehole approach for coal-bed methane drainage and ground stabilization with grouting

A shared borehole approach for coal-bed methane drainage and ground stabilization with grouting

Analysis of the Critical Safety Thickness for Pretreatment of Mined‐Out Areas Underlying the Final Slopes of Open‐Pit Mines and the Effects of Treatment

A novel short‐wall caving zone backfilling technique for controlling mining subsidence

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