Surrounding Rock Of Roadway Research Articles

Multi-Objective Optimization for Controlling Conflicts in Roadway Surrounding Rock Induced by Floor Stress-Relief Groove

This paper studies the effectiveness of the stress-relief groove on the floor of deep coal roadway and determines the influence of the stress-relief groove parameters on the surrounding rock through qualitative analysis. Based on the displacement conflict problem, evaluation indicators were established, and the optimal solution set was obtained. The innovations of this research include: 1. For geotechnical numerical simulations, novel stress monitoring and plastic zone monitoring techniques have been introduced to accurately reflect the condition of the surrounding rock; 2. The effects of floor relief grooves in deep roadway on surrounding rock have been analyzed, and the advantages and utilities of central and corner relief grooves have been determined; 3. The usability of small datasets has been enhanced by applying SEGA to optimize machine learning models with data augmentation techniques; 4. Multi-objective optimization algorithms have been applied to geotechnical engineering, providing valuable references for decision making. The results demonstrate that multi-objective optimization can significantly enhance the effectiveness of surrounding rock control, resolve conflicts, and achieve more reasonable construction plans. This research provides new theoretical foundations and practical guidance for deep mine roadway-surrounding rock control.

Study on the Influence of Crack Geometry Characteristics on Macroscopic Mechanical Properties of Roadway Surrounding Rock

Study on the Influence of Crack Geometry Characteristics on Macroscopic Mechanical Properties of Roadway Surrounding Rock

Control Method of Roadway Surrounding Rock Under the Influence of Residual Coal Pillars in Goaf

Control Method of Roadway Surrounding Rock Under the Influence of Residual Coal Pillars in Goaf

Experimental Study on the Bearing Behavior of Bolted and Grouted Broken Surrounding Rock of Deep Roadways in a Coal Mine

Experimental Study on the Bearing Behavior of Bolted and Grouted Broken Surrounding Rock of Deep Roadways in a Coal Mine

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

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.

Research on Deformation Monitoring of Roadway Surrounding Rock Based on Mobile 3D Laser Scanning Technology

Aiming at the problems of low data acquisition efficiency, unintuitive data form, low relative accuracy, and inability to continuously monitor the whole cross-section in traditional roadway rock deformation monitoring methods, a roadway rock deformation monitoring method based on mobile 3D laser scanning technology is proposed. Firstly, the mobile 3D laser scanning technology is used to obtain the real 3D point cloud data of the roadway surrounding rock; secondly, the multi-scale dimensional features are used to classify the 3D point cloud data, filter the invalid point cloud data, and form the accurate point cloud data of the roadway surrounding rock surface; then the 3D laser scanning is carried out on a regular basis for the deformation-prone areas of the roadway, and the Iterative Closest Point Algorithm (ICP algorithm) is used to align the overlapping part of the point cloud to achieve the point cloud splicing and point cloud stitching of the two scans. The point cloud splicing and point cloud overlapping of the two scans are achieved; finally, the multi-scale model-to-model point cloud comparison algorithm (M3C2 algorithm) is used to compare the point cloud data of the two periods of the roadway, and the appropriate parameters are selected to indicate the displacement change of the surface of the roadway rock with the size of the color value, so as to realize the monitoring of the deformation of the roadway rock in the three-dimensional full cross-section of the roadway. The method is applied to the deformation monitoring of the surrounding rock in the return roadway of 21407 working face in a coal mine, and the results show that: the mobile laser scanning technology can be used to obtain the complete point cloud data of the roadway, and the deformation area of the surrounding rock is successfully identified after the classification of the scanned point clouds in different time periods, the alignment of the point clouds, and the comparison of the point clouds, and the deformation condition of the surrounding rock of the roadway is visually reflected in the three-dimensional full-section deformation condition of the surrounding rock of the roadway. This method is suitable for monitoring the overall de-formation of the surrounding rock of the roadway under complex environmental conditions, and the de-formation of the surrounding rock is identified by different color areas.

Mechanical Behavior and Air Tightness of Roadway Surrounding Rock Under High Internal Pressure

Mechanical Behavior and Air Tightness of Roadway Surrounding Rock Under High Internal Pressure

Research on the Failure Mechanism of Surrounding Rock in a Dynamic Pressure Roadway and Active and Passive Coordinated Support Technology

To study the phenomenon of large deformation and the failure of roadways under dynamic pressure, this paper takes the 10607 gas drainage roadway as the research object and presents the results of a theoretical derivation of equations for the boundary of the plastic zone of a dynamic pressure roadway with and without supporting force. The impacts of the mining influence coefficient and supporting force on the plastic zone boundary were explored for various lateral pressure coefficients. As the supporting force was increased, it was observed that there was a slight reduction in the radius of the plastic zone of the dynamic pressure roadway, while its scope and shape barely changed. Based on the failure mechanism of the dynamic pressure roadway, active and passive support technology was proposed, and the support effect was analyzed using FLAC3D 5.0 numerical simulation software for the case of the 10607 gas drainage roadway.

Sub-Homogeneous Peridynamic Model for Fracture and Failure Analysis of Roadway Surrounding Rock

Sub-Homogeneous Peridynamic Model for Fracture and Failure Analysis of Roadway Surrounding Rock

Asymmetrical Deformation Mechanisms in Layered Inclined Surrounding Rock of Roadways

Asymmetrical Deformation Mechanisms in Layered Inclined Surrounding Rock of Roadways

Retracted: Deformation Analysis of Surrounding Rock of Deep Roadway by the Fluid Structure Coupling Model with MIDAS-GTS

Retracted: Deformation Analysis of Surrounding Rock of Deep Roadway by the Fluid Structure Coupling Model with MIDAS-GTS

Stability Classification of Roadway Surrounding Rock Cased on Fuzzy Comprehensive Evaluation

In order to effectively predict the stability of roadway surrounding rock, a reasonable and effective support scheme was proposed. Fuzzy clustering analysis was introduced to classify the stability of roadway surrounding rock. Based on the data processing of 7 classification indexes, the weight and subordination degree of surrounding rock indexes of roadway are established. The results show that the upper roadway of No. 111070 is a Class IV unstable roadway. The research results can provide a certain reference for the subsequent determination of the stability classification of roadway surrounding rock.

A Novel Coal Burst Criterion of Anchored Roadway Surrounding Rock under Dynamic Disturbance

Mining roadway is the main occurrence area of coal bursts in underground coal mining. A good understanding of the failure process of elastic zone and energy evolution inducing instability of support structure can offer useful insight into the coal burst mechanism. This study proposes a novel coal burst criterion of anchored roadway surrounding rock under dynamic disturbance through mechanical modeling. The coal burst hazard and its main controlling factors were studied based on case analysis, and then the application of novel criterion in coal burst prevention and control was clarified. Results show that the existence of residual energy Ur of elastic zone is a prerequisite for coal burst of the roadway. The roadway support with ultimate value Us of absorbed energy needs to resist and absorb the kinetic energy Uk released from a dynamic failure of elastic zone and the energy Up imposed by impact-induced convergence of surrounding rocks on a support system, and the novel coal burst criterion is proposed as Uk + Up > Us. Under the same support conditions, the roadway roof is more prone to dynamic failure. According to the influences of main controlling factors on coal burst hazard, the corresponding prevention and control measures can be taken from improvement for the anti-impact capability of support, pressure relief in surrounding rocks, reduction of dynamic-loading energy, and roadway restoration after coal burst.

Numerical Analysis on the Influence of Joint Density on the Stability of Complex Jointed Roadway Surrounding Rock

The random distribution of a complex joint network within a coal–rock mass has a significant weakening effect on its bearing capacity, making the surrounding rock of the roadway highly susceptible to instability and failure under the influence of in situ stress and mining-induced stress. This poses challenges in controlling the surrounding rock and seriously affects the normal production of mines. Consequently, it is imperative to conduct stability analysis on complex jointed roadway surrounding rock. Therefore, taking the transport roadway of Panel 11030 in the Zhaogu No. 2 Coal Mine as a case study, the microscopic contact parameters of particles and joint surfaces in each rock layer were calibrated through uniaxial compression and shear simulation tests using the particle flow simulation software PFC2D 5.0. Based on the calibrated microscopic contact parameters, a multilayered roadway surrounding rock model containing complex joints was established, and the joint density was quantified to analyze its effects on the displacement field, stress field, force chain field, and energy field of the roadway surrounding rock. The research findings indicate that as the distance to the sidewall decreases, the impact of joint density on the deformation of the surrounding rock of the roadway increases. The displacement of the roadway roof, floor, and sidewalls is affected differently by the joint density, predominantly contingent upon the properties of the rock mass. During the process of stress redistribution in the surrounding rock, the vertical stress of the roof and floor is released more intensively compared to the horizontal stress, while the horizontal stress of the sidewalls is released more intensively compared to the vertical stress. The increase in joint density leads to an increasing release rate of the surrounding rock stress, causing the load-bearing rock mass to transfer towards the deeper part. As the joint density increases, the force chain network gradually transitions from dense to sparse, resulting in a decrease in strong force chains and a decline in the bearing capacity of the surrounding rock, accompanied by an expansion in the range of force chain failure and deformation. With the continuous increase in joint density, the values of maximum released kinetic energy and residual released kinetic energy become larger. Once the joint density reaches a certain threshold, the kinetic energy stability zone consistently maintains a high energy level, indicating extreme instability in the roadway and sustained deformation. The results provide a valuable insight for analyzing the failure mechanism of complex jointed roadway surrounding rock and implementing corresponding support measures.

Seismic Mitigation Effect of Overlying Weakening Strata in Underground Coal Mines

Artificial construction of a weakening zone over the roadway is an essential method for preventing coal bursts and rock bursts caused by strong mining tremors. However, concerning the seismic absorption and load reduction capabilities of an artificial structural weakening zone, the degree of rock mass damage to the roadway under weakening zone protection remains unclear. This study employed principles of elasticity and UDEC (Universal Distinct Element Code) to explore the seismic attenuation and load reduction capabilities of the weakening zone. The results indicate that the absorbing ability of the weakening zone increases exponentially with its weakening coefficient. Under the same dynamic load disturbance, when the weakening coefficient rises from 0.00 to 0.99, the sidewall displacement from the elastic wave source side changes from 0.400 m to 0.228 m. The total number of cracks in the roadway-surrounding rock, and the ranges of overstressed zones decreased linearly. The critical threshold of the roadway resisting the mining tremor disturbance increased. In particular, when the mining tremor is located directly above the roadway, the initial deformation of the roof is the largest, and the cumulative deformation of the rib is greater than the roof. By creating a weakening zone with a coefficient exceeding 0.95, the roadway remains unaffected by the 20 MPa dynamic loading. The study provides a theoretical basis for controlling coal burst that is triggered by mining tremors.

Influence of Bolts and Cables on Stability of Surrounding Rock of Bottom Drainage Roadway

Influence of Bolts and Cables on Stability of Surrounding Rock of Bottom Drainage Roadway

The Deformation, Failure Mechanisms, and Stability Control of the Surrounding Rock of Deep Cross-Measure Roadway: A Case Study

In view of the difficulty in controlling the surrounding rock stability of deep cross-measure roadways, a deep cross-measure roadway of the Wanfu coal mine, a typical high-stress mine, was monitored on site and analyzed under the original support scheme. The findings show that the degrees of deformation and failure of the cross-measure roadway varied under different working conditions and that the roadway deformation and failure were mainly characterized by a high fragmentation degree and a large failure range of the surrounding rock and the frequent failure of support components. Considering that the different parts of the cross-measure roadway are located in different lithostratigraphic units, establishing a numerical model of the cross-measure roadway under different working conditions; analyzing the deformation pattern of the surrounding rock of the roadway, the plastic range, and the morphological change pattern; and clarifying the deformation and failure mechanisms of the cross-measure roadway based on field monitoring results. On this basis, two types of evaluation indicators, that is, the deformations of the surrounding rock and the plastic ranges in the four typical parts (roof, shoulder, floor, and sidewalls) of the roadway, were selected to rate the stability of the roadway under different working conditions. Grouting reinforcement-based targeted control countermeasures are proposed to improve the surrounding rock stability. Subsequently, numerical analysis and field application of these control countermeasures were carried out to solve the problem of controlling the surrounding rock stability of deep cross-measure roadways.

Numerical Simulation Verification of the Application of Inorganic Thermal Insulation Materials to the Surrounding Rock of Roadways

Insulation materials provide a new solution for heat dissipation control in high-temperature mine enclosures. In this paper, ANSYS Fluent was selected to conduct a numerical simulation study on the heat transfer after inorganic insulation materials were laid on the surface of the mine tunnel surrounding rock. The results show that the influence of the tunnel wind flow on the temperature of the surrounding rock is related to the support material laid, and the temperature of the surrounding rock wall after laying inorganic insulation material is about 4°C lower than that of ordinary concrete support. The temperature difference of the surrounding rock wall at the entrance of the tunnel is about 4.6°C, and that of the surrounding rock wall at the exit is about 2.8°C. The comparative analysis verifies that the insulation material positively affects the heat dissipation control of the high-temperature shaft and the surrounding rock of the roadway.

Energy Accumulation Characteristics and Induced Rockburst Mechanism of Roadway Surrounding Rock under Multiple Mining Disturbances: A Case Study

The source of energy release when rockburst occurs must be determined to understand the mechanisms underlying disaster formation and achieve accurate prevention and control. Although previous research has systematically investigated the energy source underlying rockburst from different perspectives, issues such as an unclear understanding of the energy accumulation state and inaccurate positioning of the energy release source remain to be resolved. In this study, the “1·17” major roof accident in the Danshuigou Mine was used as the background to evaluate and analyze the stress environment and energy accumulation characteristics of roadway surrounding rock under multiple mining disturbances, and the results showed that a super energy package occurs in the surrounding rock of the mining roadway. Subsequently, the evolution process of energy in this region and the mechanism of induced rockburst were elaborated. The results showed that the degree of stress concentration in the surrounding rock of the roadway will increase several times as the number of mining disturbances increases. Under the influence of multiple mining disturbances, the maximum principal stress peak of the surrounding rock of the roadway can reach 5–10 times the maximum principal stress value outside the mining-affected area. A large amount of elastic energy was accumulated in the rock surrounding the roadway, and super-high-density energy packages were formed locally. The maximum energy density value reached 50–185 times the value observed in areas outside the mining-affected zone. Thus, rockburst may be induced when the large amount of energy accumulated in the super energy package is suddenly and violently released; moreover, the degree of energy accumulation in the super energy package is likely closely related to the magnitude of rockburst. These results have important theoretical significance and application value for clarifying the mechanism of rockburst and improving the effectiveness of rockburst prediction and prevention.

Non-orthogonal Failure Behavior of Roadway Surrounding Rock Subjected to Deep Complicated Stress

Non-orthogonal Failure Behavior of Roadway Surrounding Rock Subjected to Deep Complicated Stress