Numerical Simulation of Factors on Zonal Disintegration in Surrounding Rocks of Deep Roadways

Ning, Jian; Liu, Xuesheng; Li, Hai Tao

doi:10.4028/www.scientific.net/amr.518-523.5935

Cited by 2 publications

(2 citation statements)

References 2 publications

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“…Gao et al simulated the development characteristics of the fractures in homogeneous surrounding rocks based on a bilinear strain-softening ubiquitous-joint model in FLAC 2D . Nevertheless, they did not observe annular disintegration zones in alternate patterns [15].…”

Section: Introductionmentioning

confidence: 85%

Study on Shear Failure Process and Zonal Disintegration Mechanism of Roadway under High Ground Stress: A Numerical Simulation via a Strain-Softening Plastic Model and the Discrete Element Method

Yang,

Zhang,

Liu

2024

Applied Sciences

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Fracture expansion in rock masses can be observed by monitoring the break of contacts between the bounding particles via the discrete element method. The latter’s realization in this study via the PFC2D program tracked the evolution process of the zonal disintegration in an exemplary roadway-surrounding rock affected by mining. Besides, the damage evolution pattern in a high-stress soft rock roadway was simulated by the FLAC2D program using a strain-softening plastic model, revealing the effects of rock mass strength, stress state, and anchor support on the zonal disintegration of the roadway. Numerical simulation results show that in a roadway with high-level stress, the obvious fractures spread from the roadway surface to the depth of the surrounding rock along a series of geometric planes and cut the surrounding rock into rock mass blocks. Under high crustal stress, conjugate shear fractures occur near the roadway surfaces and form a closed-loop fractured zone after intersecting the conjugate fracture faces. The closed fractured zone becomes a free face, from which conjugate shear fractures develop, forming new closed fractured zones in the deep surrounding rock. By repeatedly generating the closed fracture zones, a fracture network appears in the roadway-surrounding rock. The development of zonal disintegration of roadway-surrounding rock mainly depends on the rock mass strength and its stress state. Zonal disintegration only occurs when the crustal stress of the roadway-surrounding rock exceeds its strength. When the horizontal stress is low and the vertical stress exceeds the rock mass strength, zonal disintegration only occurs on two sides of the roadway. When the vertical stress is low and the horizontal stress exceeds the rock’s mass strength, it only appears on the roof and floor. When the values of cohesion, internal friction angle, and tensile strength are reduced in the same proportion, cohesion has the greatest impact on the expansion of the zonal disintegration zone, followed by the internal friction angle, while the tensile strength effect is the least. In anchor-supported roadways undergoing zonal disintegration processes, the intact zone blocks slide relatively along the fracture surface during the process of loosening and deformation of the surrounding rock, making the anchor rods susceptible to tensile, shear, and bending actions.

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Section: Introductionmentioning

confidence: 85%

Study on Shear Failure Process and Zonal Disintegration Mechanism of Roadway under High Ground Stress: A Numerical Simulation via a Strain-Softening Plastic Model and the Discrete Element Method

Yang,

Zhang,

Liu

2024

Applied Sciences

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“…Wang [15] proposed a new computational method to calculate the storage elastic-energy value of the surrounding rocks, based on numerical simulation and theoretical calculation. Ning [16] put forward that, when the energy reaches a certain level, the rock burst will occur. He [17] proposed a rock-burst proneness prediction method, based on rock digital drilling.…”

Section: Introductionmentioning

confidence: 99%

Relief Mechanism of Segmented Hole Reaming and Stress Distribution Characteristics of Drilling Holes in Deep Coal Mine

et al. 2022

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As the mining depth increases, in underground tunnels, caverns or pillar goaf, a rock burst is one of the important accidents that threaten mine safety. Drilling pressure relief becomes one of the main means of preventing rock bursts, which affect the mechanical properties and stability of the coal and rock in underground excavations. However, the surrounding rock of the roadway or the coal body is usually broken, and the pressure relief of the large-diameter borehole will affect its support. A segmented hole-reaming technology is proposed and applied in a coal mine in China. A pressure-relief mechanic model of segmented hole reaming was built. The coal sample had an elastic modulus of 0.35 GPa, the UCS and UTS were 17.4 MPa and 1.41 MPa, the Poisson ratio was 0.27, the cohesive force was 2.81 MPa, and the friction was 23.7°. The pressure relief range of the boreholes with different diameters, horizontal in situ stress coefficients, cohesive forces, and friction angles were analyzed. When the drill hole was increased from 120 mm to 200 mm, the pressure relief range was increased by 57.1%. The stress distribution of the staged reaming and pressure-relief drilling was also obtained. In the vertical direction, the vertical stress of the borehole first decreased and then was restored to the original rock stress area, and in the horizontal direction, it first increased and then was restored to the original rock stress area. A CMS1-6200 segmented drilling rig was used to construct the pressure relief hole. The weight of the drilled pulverized coal was monitored at different depths. The results showed that the amount of pulverized coal in all of the drilled holes was less than 3 kg/m, indicating that the effect of reducing the pressure relief is obvious. The study is of great significance to research the pressure relief range, mechanical characteristics and stress distribution of segmented hole reaming; it also provides insight into the rock burst prevention and the design of drilling in the mine site.

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Numerical Simulation of Factors on Zonal Disintegration in Surrounding Rocks of Deep Roadways

Cited by 2 publications

References 2 publications

Study on Shear Failure Process and Zonal Disintegration Mechanism of Roadway under High Ground Stress: A Numerical Simulation via a Strain-Softening Plastic Model and the Discrete Element Method

Study on Shear Failure Process and Zonal Disintegration Mechanism of Roadway under High Ground Stress: A Numerical Simulation via a Strain-Softening Plastic Model and the Discrete Element Method

Relief Mechanism of Segmented Hole Reaming and Stress Distribution Characteristics of Drilling Holes in Deep Coal Mine

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