Failure and Seepage Characteristics of Gas-Bearing Coal under Accelerated Loading and Unloading Conditions

Zhang, Xiang; Wang, Kai; Du, Feng; Lou, Zhen; Wang, Gongda

doi:10.3390/app9235141

Cited by 5 publications

(2 citation statements)

References 37 publications

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“…Using the Moore-Cullen criterion [39], the following conditions can be obtained for the stress in the plastic zone of the roadway envelope:…”

Section: Calculation Of Plastic Boundary Of Circular Roadway Enclosur...mentioning

confidence: 99%

TBM Rapid Tunneling Roadway Support Parameters Design and Process Research

Hou,

Xie,

Zhang

et al. 2023

Processes

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Taking the specific production geological conditions of the auxiliary transportation lane in the west area of Gaojiabao coal mine of Shaanxi Zhengtong Coal Industry as the research background, based on the anchorage support theory and the characteristics of the TBM digging process, numerical simulation, theoretical analysis, and other research methods were used to investigate the depth of the destruction of the plastic zone of the surrounding rock of the roadway to form the reasonable support parameters of a large cross-section of hard rock roadway suitable for TBM digging and to propose an intelligent digging and support process of the TBM corresponding to the on-site practice. The proposed intelligent tunneling support technology corresponds to a field practice of TBM. The study shows that: combined with the field industrial test and adjusted by the peripheral rock deformation and damage law, the anchor diameter of 20 mm, the length of 2500 mm left-hand threaded steel anchors, row spacing of 1100 mm, spacing of 1200 mm, and the anchor diameter of Φ21.8 mm, the length of 6200 mm left-handed threaded steel anchors, row spacing of 1100 mm, spacing of 1200 mm are the most reasonable solutions, which can ensure the control of the tunnel peripheral rock. The program is the most economically efficient in ensuring the control of deformation of the roadway perimeter rock and maintaining normal use.

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“…Using the Moore-Cullen criterion [39], the following conditions can be obtained for the stress in the plastic zone of the roadway envelope:…”

Section: Calculation Of Plastic Boundary Of Circular Roadway Enclosur...mentioning

confidence: 99%

TBM Rapid Tunneling Roadway Support Parameters Design and Process Research

Hou,

Xie,

Zhang

et al. 2023

Processes

View full text Add to dashboard Cite

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“…Liu 10 investigated the damage mechanism during overexcavation of deep tunnels and constructed a damage model of the surrounding rock conforming to the Hoek−Brown damage criterion by using the limit analysis method and the generalized function theory, so as to predict the damage pattern of the surrounding rock, the scope of collapse, and the backfilling area in the process of overexcavation. Wang 11 investigated the mechanical seepage characteristics of gas-containing coal rocks and analyzed the mechanical properties and energy response characteristics of gas-containing coal rocks using triaxial experiments at different maximum principal stress loading rates. Wang 12 investigated the deformation and damage characteristics of coal during the coal and gas protrusion process and provided a new method for testing the damage of the coal and rock body and gas transportation characteristics during the occurrence of gas dynamic disasters by developing an experimental device for sudden unloading of coal and rock under different gas pressures.…”

Section: Introductionmentioning

confidence: 99%

Study on Numerical Simulation of Large-Diameter Borehole Pressure Relief in Deep High-Gas Soft Coal Seams

Yang,

Liu,

Fan

et al. 2024

ACS Omega

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The deep highly gassy soft coal seam has the characteristics of high ground stress, high gas pressure, and low permeability. In the process of coal roadway excavation, there are problems such as frequent gas concentration exceeding the limit and easy induction of gas dynamic disasters. To investigate the pressure relief and disaster reduction efficiency of large-diameter boreholes in a deep high-gas soft coal seam, the 8002 high-gas working face of the Wuyang coal mine was taken as the engineering background to study the deformation law of large-diameter boreholes in deep high-gas soft coal seams. A coupled damage–stress–seepage model for pressure relief of large-diameter boreholes in gas-bearing coal seams was constructed based on the Hoek–Brown criterion, the correlation between the damage area and the gas pressure distribution in the gas-bearing coal seam after the pressure relief of boreholes of different apertures was analyzed, and the pressure relief efficiency of different technical parameters “three flower holes” in the roadway head was determined. The law of stress transfer, gas migration, and energy release in the coal seam after pressure relief of a large-diameter borehole under different initial gas pressures was revealed, and the power function equations of the damage range and borehole diameter, maximum stress at the roadway head, and driving distance after pressure relief of a gas-bearing coal seam were determined. Results showed that under the confining pressure of the 8002 working face roadway in the Wuyang coal mine, the pressure relief effect of 250 mm aperture is better, the drilling plastic zone is “butterfly” or “X″-type distribution, and the plastic zone range is positively correlated with the aperture size. Under the arrangement of “three flower holes”, the plastic zone is larger and the pressure relief effect is better when the hole spacing is 1.4 m. With the increase of initial gas pressure, the vertical stress above the borehole increases and the pressure relief efficiency decreases. According to the vertical stress distribution within 200 h of borehole pressure relief, the pressure relief process is divided into a coal damage and failure stage, stress balance stage, and hole collapse stability stage. The research results provide a theoretical basis for the prevention and control of coal rock gas dynamic disasters by large-diameter drilling in a deep high-gas soft coal seam.

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