Failure Characteristics and Stability Control of Bolt Support in Thick‐Coal‐Seam Roadway of Three Typical Coal Mines in China

Xiang, Zhe; Zhang, Nong; Qian, Deyu; Xie, Zhengzheng; Zhang, Chenghao; Guo, Feng; Wang, Sujian

doi:10.1155/2021/5589085

Cited by 3 publications

(2 citation statements)

References 34 publications

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“…Therefore, the anchored rock beams that are thick enough are constructed with prestressed bolts to eliminate the abscission layer and two types of destabilization, thus realizing the bidirectional linkage within the same layer and among different layers. A thick anchorage-bearing layer is built using flexible supporting rods [34,35], as shown in Figure 11. This layer spans the shallow damage zone to provide a larger load-bearing circle for the surrounding rock so that the deformation in shallow strata can be restrained through the long-term stabilization of the less damaged surrounding rock in deep strata.…”

Section: Continuous Roof Control Theory and Technology For High-stres...mentioning

confidence: 99%

Deformation Failure Characteristics and Maintenance Control Technologies of High-Stress Crossing-Seam Roadways: A Case Study

Xie

Xiang

et al. 2023

Applied Sciences

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The surrounding rock structure of the crossing-seam roadway is poor and is susceptible to anchorage failure phenomena, such as top plate sinking and convergence deformation under high ground stress. These issues can cause significant deformation of the surrounding rock over time, resulting in challenging engineering problems. To address this issue, we studied the failure modes and destabilization mechanisms of the surrounding rock in different crossing-seam roadways by field tests and numerical simulations. The results show that since the rock strata in these roadways are extremely unstable and highly susceptible to high horizontal stress, the weak surrounding rock presents the mode of full-section plastic failure. The roof is damaged more seriously than the floor and both walls. In this case, the basic anchorage layer in the original scheme is not thick and rigid enough to support these roadways. Thus, the surrounding rock deforms severely and persistently, which is one of the engineering failure characteristics. To solve this problem, a new scheme of “prompt thick-layer end anchorage + full-length lag grouting anchorage + secondary continuous reinforcement” was proposed based on the continuous roof control theory. According to the industrial test, this scheme can successfully control the long-term large deformation of the weak surrounding rock in crossing-seam roadways. Notably, the deformation of the top plate decreased by 56.65% and the deformation of the two walls decreased by 66.35%. Its design concept will provide important references for controlling the surrounding rock in similar soft rock roadways.

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Section: Continuous Roof Control Theory and Technology For High-stres...mentioning

confidence: 99%

Deformation Failure Characteristics and Maintenance Control Technologies of High-Stress Crossing-Seam Roadways: A Case Study

Xie

Xiang

et al. 2023

Applied Sciences

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“…The support of roadways has transformed from traditional shed supports to bolt supports [16][17][18]. Sun Xiaoming et al proposed bolt-mesh-cable coupled support technology [19,20], the active pressure relief method [21,22], subregional and phased dynamic control technology [23,24], and prestressed truss anchor cable control technology from multiple perspectives [25] and realized the effective control of the deformation of the rock surrounding soft rock roadways. For the study of soft rock roadway support, we focus on soft rock, clarify the mechanical deformation mechanism and nonlinear deformation behavior of soft rock, identify the key aspects of support technology [26,27], and implement effective roadway support design to fundamentally solve the deformation problem of soft rock roadways.…”

Section: Introductionmentioning

confidence: 99%

Study of the Failure Mechanism of Soft Rock Mining Roadways Based on Limit Analysis Theory

Zhang,

Gao,

Yang

et al. 2023

Applied Sciences

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To study the deformation and failure mechanisms of soft rock mining roadways, the 1506 return airway of Anyang Coal Mine is taken as the engineering background. Based on limit analysis theory, a failure model based on a rigid slider system is constructed to assess the failure of the soft rock surrounding a roadway. The formulas for calculating the self-weight power of the slider in the velocity discontinuity line of the rock surrounding the roadway, the work power of the surrounding rock pressure, and the energy dissipation rate of the velocity discontinuity line are derived, and the upper limit objective function of the velocity discontinuity line height is obtained. The failure characteristics and fracture evolution process of the surrounding rock under different mining stresses are analyzed by means of physical similarity simulations. The simulation results show that shear failure occurs first on the roadway side due to stress concentration. The fissures expand along the bottom angle of the roadway to the blind support area and the low-intensity support area. The cracks weaken the support strength of the angled anchor cable and bolt in the roadway shoulder. Under the action of roof pressure, the status of the rock mass inside and outside the shear slip zone changes from static to dynamic. This causes deformation and failure of the roadway roof, side, and floor.

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A New Method for Controlling Rockbursts in the Mining Roadway of Ultrathick Coal Seams Based on the Dual Pressure Relief Method

Wang

et al. 2021

Shock and Vibration

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To control rockbursts in mining roadways in ultrathick coal seams, a new method for preventing rockbursts through dual pressure relief by roof cutting through cumulative blasting in medium-deep boreholes from the conveyor gateway and return airway was proposed. The mechanical characteristics of key overlying strata of the working face under the effect of dual pressure relief were theoretically investigated. Furthermore, a mathematical relationship between the roof-cutting depth and the advanced abutment pressure on the working face was established to reveal the mechanism of dual pressure relief in controlling rockbursts. Moreover, the effect of the dual pressure relief method on controlling rockbursts was validated through numerical simulation and field testing. Results showed that artificially increasing the caving height of gangues in goaf based on the dual pressure relief method can restrict the subsidence of key strata, thus reducing the advanced abutment pressure of the working face; the method influences a range of 20 m in front of the working face along the strike and areas 30 m away from the two roadways along the dip. The average energy density of coal in the side of the conveyor gateway is decreased by 15.4%, while that in the side of return airway is reduced by 13.8% within the range of influence. The field test results indicated that the average pressure on support declines by 21.4% within 30 m from the working face to the conveyor gateway, while it decreases by 20.5% within that region 25 m from the return airway by using the dual pressure relief method. After conducting dual pressure relief, the total number of microseismic (MS) events during mining of the working face is decreased by 25.4%. The number of MS events with energy release exceeding 103 J falls by 36.6%, while the number of events releasing less than 103 J is increased by 28.6%. The characteristics of MS energy release change from coexistence of low-energy events and a small number of high-energy events to the occurrence of numerous low-energy events. Results can verify the effectiveness of the dual pressure relief method in controlling rockbursts in the mining roadway of ultrathick coal seams.

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Failure Characteristics and Stability Control of Bolt Support in Thick‐Coal‐Seam Roadway of Three Typical Coal Mines in China

Cited by 3 publications

References 34 publications

Deformation Failure Characteristics and Maintenance Control Technologies of High-Stress Crossing-Seam Roadways: A Case Study

Deformation Failure Characteristics and Maintenance Control Technologies of High-Stress Crossing-Seam Roadways: A Case Study

Study of the Failure Mechanism of Soft Rock Mining Roadways Based on Limit Analysis Theory

A New Method for Controlling Rockbursts in the Mining Roadway of Ultrathick Coal Seams Based on the Dual Pressure Relief Method

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