Application of a combined support system to the weak floor reinforcement in deep underground coal mine

Kang, Yongshui; Liu, Quansheng; Gong, Guangqing; Wang, Huaichao

doi:10.1016/j.ijrmms.2014.03.017

Cited by 112 publications

(47 citation statements)

References 10 publications

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“…In addition, the characteristics and evolution mechanism of floor heave in gob-side entry were studied. The evolution process can be divided into five stages (slip-bend line formation, shear dislocation failure, shear breakage, extrusion flow, and delamination stages) [29][30][31][32]. Second, the roadway support technology of GER is improved [33][34][35].…”

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confidence: 99%

Roof Cutting Parameters Design for Gob-Side Entry in Deep Coal Mine: A Case Study

et al. 2019

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Roof cutting is an effective technique for controlling the deformation and failure of the surrounding rock in deep gob-side entry. The determination of the roof cutting parameters has become a popular research subject. Initially, two mechanical models are established for the non-roof-cutting and roof-cutting of gob-side entry in deep mining conditions. On this basis, the necessity and significance of roof cutting is revealed by analysing the stress and displacement of roadside prop. The Universal Distinct Element Code numerical simulation model is established to determine the key roof-cutting parameters (cutting angle and cutting height) according to the on-site situation of No. 2415 headentry of the Suncun coal mine, China. The numerical simulation results show that with the cutting angle and height increase, the vertical stress and horizontal displacement of the coal wall first increase and then decrease, as in the case of the vertical stress and displacement of roadside prop. Therefore, the optimum roof cutting parameters are determined as a cutting angle of 70 • and cutting height of 8 m. Finally, a field application was performed at the No. 2415 headentry of the Suncun coal mine. In situ investigations show that after 10 m lagged the working face, the stress and displacement of roadside prop are obviously reduced with the hanging roof smoothly cut down, and they are stable at 19 MPa and 145 mm at 32 m behind the working face, respectively. This indicates that the stability of the surrounding rock was effectively controlled. This research demonstrates that the key parameters determined through a numerical simulation satisfactorily meet the production requirements and provide a reference for ensuring safe production in deep mining conditions. about 100-500 m, the microstructures, basic mechanical characteristics, and engineering responses of coal and rock have changed significantly in response to the "three highs and one disturbance" environment [10][11][12][13]. The main features are that the surrounding rock has a large deformation, high deformation speed, long deformation duration, and rheological characteristics. Hence, maintenance of the gob-side entry becomes extremely difficult, and large deformation and failure accidents occur occasionally [14][15][16][17][18].Many theoretical studies and field practices on GER technology under deep mining conditions have been completed, and three major advancements should be considered. First, the surrounding rock deformation characteristics and failure evolution law of deep GER are revealed under various geological conditions [19][20][21][22][23]. The roof of the gob-side entry is simplified into a rectangular "superposed stratified plate" structure [24,25], and the concept of the strip segmentation method for the roof load is proposed according to the theory of elastoplastic mechanics. On this basis, used a numerical analysis method to identify the influence mechanism of the roof fracture location, roof rotation, and long-term creep of the surrounding rock in deep ...

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confidence: 99%

Roof Cutting Parameters Design for Gob-Side Entry in Deep Coal Mine: A Case Study

et al. 2019

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“…In-situ stress is a principal element which causes rock deformation and failure, and its magnitude and orientation significantly affect the stability of roadways [23,24]. In order to investigate the in-situ stress of Zhangji coal mine, borehole stress relief measurements were conducted in the mine's roadways by Anhui University of Science and Technology.…”

Section: In-situ Stress Fieldmentioning

confidence: 99%

Supporting Design Optimization of Tunnel Boring Machines-Excavated Coal Mine Roadways: A Case Study in Zhangji, China

et al. 2020

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Tunnel Boring Machines (TBMs) are a cutting-edge excavating equipment, but are barely applied in underground coal mines. For TBM excavation projects involving the Zhangji coal mine, the surrounding rock properties, stress field, cross section geometry, as well as the excavation-induced stress path of TBM-excavated coal mine roadways are different from those of traditional tunnels or roadways. Consequently, traditional roadway supporting technologies and experiences cannot be relied on for this project. In order to research an appropriate supporting pattern for a TBM-excavated coal mine roadway, first of all, the constitutive model of roadway surrounding rocks was derived, and a rock failure criterion was proposed based on rock mechanical tests. Secondly, a three-dimension finite element model was established and computer simulations under three different supporting patterns were conducted. Stress redistribution, roadway convergence, and excavation damage zone ranges of surrounding rocks under three different support patterns were analyzed and an optimal support design of the TBM-excavated roadway was made based on simulation results. During roadway excavation, convergence gauge and rock bolt dynamometers were installed for monitoring roadway convergence and the axial forces of rock bolts. The in-situ monitoring results verified the validity of roadway supporting designs.

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“…In extreme conditions, the larger roadway convergence and reduction of the roadway cross section may occur frequently . To address this issue, the conventional support techniques such as rock bolting, U‐shaped steel sets, concrete steel sets, and some compound systems have been tried and succeed in some cases . However, the mentioned methods normally emphasized the high‐rigidity and high‐strength support on surrounding rock mass and neglected the rheological properties of coal mass.…”

Section: Introductionmentioning

confidence: 99%

Investigation on jet grouting support strategy for controlling time‐dependent deformation in the roadway

Sun

Zhang

2020

Energy Science & Engineering

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The efficiency of coal mining is seriously affected by roadway stability, as large time‐dependent deformation of roadway frequently occurs and needs to be maintained several times during its service life. Such rheological deformation was common in soft coal mass at Huaibei coalfield in China. To address this issue, in this study, the time‐dependent deformation of the soft coal roadway was analyzed and a new Jet Grouting (JG) technique was presented for controlling deformation. The time‐dependent deformation of the soft coal roadway was numerically simulated and validated. Based on the field test results and the verified model, a JG support model was established to examine its effect on roadway deformation. The JG support system can reduce the horizontal and vertical displacement of the roadway effectively and constrain the time‐dependent deformation of coal mass. The deformation rate and stabilization time of roadway decreased significantly by comparison with conventional support. This work presented a promising JG support scheme for controlling the time‐dependent deformation in the roadway in deep underground mine, which can greatly promote the JG design and application.

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Application of a combined support system to the weak floor reinforcement in deep underground coal mine

Cited by 112 publications

References 10 publications

Roof Cutting Parameters Design for Gob-Side Entry in Deep Coal Mine: A Case Study

Roof Cutting Parameters Design for Gob-Side Entry in Deep Coal Mine: A Case Study

Supporting Design Optimization of Tunnel Boring Machines-Excavated Coal Mine Roadways: A Case Study in Zhangji, China

Investigation on jet grouting support strategy for controlling time‐dependent deformation in the roadway

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