scholarly journals Review of the Evolution of Mining-Induced Stress and the Failure Characteristics of Surrounding Rock Based on Microseismic Tomography

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Qiankun Zhu ◽  
Xingdong Zhao ◽  
Erik Westman
Keyword(s):  
Numerical Simulation ◽  
Stress Field ◽  
Stress Measurement ◽  
High Stress ◽  
Mining Industry ◽  
Microseismic Monitoring ◽  
Surrounding Rock ◽  
Research Progress ◽  
Induced Stress ◽  
Velocity Tomography

With the gradual depletion of shallow resources, deep mining has become an inevitable trend and has become an important part of the world mining industry. The high stress concentration caused by redistribution of original stress field will lead to stress-driven failure of surrounding rock; conventional methods, such as point-location stress measurement, analytical analysis, numerical simulation, and physical modeling, are not able to completely reflect the distribution and evolution characteristics of the mining-induced stress field in real time and at mine scale, so it is difficult to fully understand, control, and prevent mining-induced injuries and fatalities. In the past decades, microseismic monitoring technology, velocity tomography, numerical simulation, and laboratory test technology have been successfully applied to better understand mining-induced stress and rock mass failures. The combination of these methods has led to innovative ways to investigate the mining-induced stress field, surrounding rock failure, and hazard prevention. This review focuses on the mining-induced stress and velocity tomography based on microseismic monitoring data. Research progress in analysis and measurement methods of mining-induced stress, rock mechanics for mining, and velocity tomography practices are presented.

Numerical Simulation for Destroy Pattern of Surrounding Rock of Circle Tunnel with M-H Coupling Action

2011 ◽  
Vol 71-78 ◽  
pp. 3572-3576
Author(s):  
An Nan Jiang ◽  
Peng Li
Keyword(s):  
Numerical Simulation ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Rock Fracture ◽  
High Stress ◽  
Surrounding Rock ◽  
Zonal Disintegration ◽  
Affecting Factors ◽  
Tunnel Wall ◽  
Shear Belt

The uniform zonal disintegration of surrounding rock is the peculiar phenomena of deep and high stress field, researching the inner mechanism and affecting factors has important meaning for guaranteeing the safety of deep engineering. The paper adopted strain soft Mohr-Coulomb model and carried out numerical simulation of surrounding rock fracture and excavation. The simulation states that along with the unloading time accumulation, the shear belt produced from tunnel wall and developed to inner rock. The corresponding shear stress concentration zone also spread to inner rock and destroy zone increasing. The pore water pressure increasing will accelerate the shear belt developing and increase the destroy degree.

Development and Application of Complementary Support Technology under the Condition of Weak and Broken Surrounding Rocks

2011 ◽  
Vol 243-249 ◽  
pp. 3389-3398
Author(s):  
Hong Wei Wang ◽  
Yao Dong Jiang ◽  
Jie Zhu ◽  
Xian Tao Zeng ◽  
Peng Fei Jiang ◽  
...  
Keyword(s):  
Coal Mine ◽  
Rock Strength ◽  
High Stress ◽  
Surrounding Rock ◽  
Deep Mining ◽  
Induced Stress ◽  
Geological Conditions ◽  
Support Force ◽  
Support Element ◽  
Yielding Support

The support of surrounding rock under the condition of deep mining has significant challenges due to high stress and low rock strength environment. Using the method of strengthening broken rock, reinforcing support force and releasing the mine-induced stress, this study has pointed out the complementary support technology which is based on the support using bolt-wire-shotcrete and is combined with steel arched yielding support. For the purpose of permanent support, the complementary support technology could combine the each support element and adequately take advantage of load-caring capacity of surrounding rock. The monitoring data of Xiaokang coal mine, Muchengjian coal mine and Yangquhe coal mine indicate that, for the various geological conditions, complementary support system has provided powerful support force to resist large deformation of weak and broken surrounding rock. It is proved that this type of support technology could reduce the mine-induced stress as well and has economical significance.

scholarly journals Research on the Deformation Mechanism and Directional Blasting Roof Cutting Control Measures of a Deep Buried High-Stress Roadway

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xiaojie Yang ◽  
Chenkang Liu ◽  
Honglei Sun ◽  
Songlin Yue ◽  
Yuguo Ji ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Stress ◽  
Stable State ◽  
Surrounding Rock ◽  
Pressure Relief ◽  
Working Face ◽  
Rock Structure ◽  
Stress Fluctuation ◽  
Roadway Deformation ◽  
Cutting Height

Affected by the mining activities of the working face, the surrounding rock of the roadway is easily deformed and destroyed. For deep buried roadways, the deformation and destruction of the surrounding rock is particularly prominent. Under the influence of in situ stress fluctuation, 3−1103 tailgate of the Hongqinghe coal mine was in a complex stress environment with a maximum stress exceeding 20 MPa. Affected by mining stress, the roadway behind the working face was seriously deformed. In order to alleviate the deformation of the roadway, directional blasting and cutting measures for the 3−1103 tailgate were adopted in this paper. The mechanism of crack propagation in single-row to three-hole directional blasting was revealed by numerical simulation. The blasted rock was divided into three regions according to the crack condition. The numerical analysis of the cutting heights of 0 m, 10 m, 12 m, and 14 m, respectively, showed the stress peaks of different cutting heights and the deformation law of the surrounding rock. The pressure relief effect was the best at 14 m cutting height. At this time, the peak stress was 39 MPa with the smallest roadway deformation. Based on numerical simulation and theoretical analysis results, engineering tests were carried out. Field monitoring showed that the deformation of the roadway was inversely proportional to the roof cutting height. The higher the cutting height is, the more preferential the roadway is to reach the stable state. It can be concluded that directional blasting can change the surrounding rock structure, control the deformation of the roadway, and play a role in pressure relief. It provides a new measure to control roadway deformation.

scholarly journals Study on Three-Dimensional Stress Field of Gob-Side Entry Retaining by Roof Cutting without Pillar under Near-Group Coal Seam Mining

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 552 ◽  
Author(s):  
Xiaoming Sun ◽  
Yangyang Liu ◽  
Junwei Wang ◽  
Jiangbing Li ◽  
Shijie Sun ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Stress Field ◽  
High Stress ◽  
Peak Stress ◽  
Horizontal Stress ◽  
Surrounding Rock ◽  
Distribution Law ◽  
Working Face ◽  
Pillar Mining ◽  
Seam Mining

In order to explore the distribution law of stress field under the mining mode of gob-side entry retaining by roof cutting without pillar (GERRCP) under goaf, based on the engineering background of 8102 and 9101 working faces in Xiashanmao coal mine, the stress field distribution of GERRCP and traditional remaining pillar was studied by means of theoretical analysis and numerical simulation. The simulation results showed that: (1) in the front of the working face, the vertical peak stress of non-pillar mining was smaller than that of the remaining pillar mining, and it could effectively control stress concentration in surrounding rock of the mining roadway; the trend of horizontal stress distribution of the two was the same, and the area, span and peak stress of stress the rise zone were the largest in large pillar mining and the minimum in non-pillar mining. (2) On the left side of the working face, the vertical stress presented increasing-decreasing characteristics under non-pillar mining mode and saddle-shaped distribution characteristics under the remaining pillar mining mode respectively. Among them, the peak stress was the smallest under non-pillar mining, and compared with the mining of the large pillar and small pillar, non-pillar mining decreased by 12–21% and 3–10% respectively. The position of peak stress of the former was closer to the mining roadway, indicating that the width of the plastic zone of the surrounding rock of the non-pillar mining was smaller and bearing capacity was higher. In the mining of the large and small pillar, the horizontal stress formed a high stress concentration in the pillar and 9102 working face respectively. In non-pillar mining, the horizontal stress concentration appeared in solid coal, but the concentration area was small.

scholarly journals Characteristics of evolution of mining-induced stress field in the longwall panel: insights from physical modeling

2021 ◽  
Author(s):  
Jinfu Lou ◽  
Fuqiang Gao ◽  
Jinghe Yang ◽  
Yanfang Ren ◽  
Jianzhong Li ◽  
...  
Keyword(s):  
Stress Field ◽  
Theoretical Analysis ◽  
Principal Stress ◽  
Physical Modeling ◽  
Large Scale ◽  
High Stress ◽  
Obtuse Angle ◽  
Induced Stress ◽  
In Situ Conditions ◽  
Longwall Panel

AbstractThe evolution of mining-induced stress field in longwall panel is closely related to the fracture field and the breaking characteristics of strata. Few laboratory experiments have been conducted to investigate the stress field. This study investigated its evolution by constructing a large-scale physical model according to the in situ conditions of the longwall panel. Theoretical analysis was used to reveal the mechanism of stress distribution in the overburden. The modelling results showed that: (1) The major principal stress field is arch-shaped, and the strata overlying both the solid zones and gob constitute a series of coordinated load-bearing structures. The stress increasing zone is like a macro stress arch. High stress is especially concentrated on both shoulders of the arch-shaped structure. The stress concentration of the solid zone in front of the gob is higher than the rear solid zone. (2) The characteristics of the vertical stress field in different regions are significantly different. Stress decreases in the zone above the gob and increases in solid zones on both sides of it. The mechanical analysis show that for a given stratum, the trajectories of principal stress are arch-shaped or inversely-arched, referred to as the “principal stress arch”, irrespective of its initial breaking or periodic breaking, and determines the fracture morphology. That is, the trajectories of tensile principal stress are inversely arched before the first breaking of the strata, and cause the breaking lines to resemble an inverted funnel. In case of periodic breaking, the breaking line forms an obtuse angle with the advancing direction of the panel. Good agreement was obtained between the results of physical modeling and the theoretical analysis.

scholarly journals Numerical Simulation and Analysis of Tunnel Failure Mode by Stochastic Fracture Model

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Fukun Xiao ◽  
Lei Xu ◽  
Gang Liu ◽  
Zhiyuan Hou ◽  
Le Xing
Keyword(s):  
Numerical Simulation ◽  
Rock Burst ◽  
Monte Carlo Model ◽  
High Stress ◽  
Tectonic Stress ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Structural Plane ◽  
Dip Angle ◽  
The Stability

The dip angle, length, spacing, and fracture distance of rock fissure affect the morphology of roadway after collapse. The numerical simulation software CDEM is used to simulate the morphology of roadway collapse. The Monte Carlo model is used to simulate different types of crack models in two-dimensional plane and generate different crack models. The effects of crack angle, crack length, fracture distance, and spacing on the deformation of surrounding rock are analyzed. The influence of different rock burst on the failure strap-fall modes of fissure roadway and roadway in different sections is analyzed, and the stability law of roadway is studied. Under the condition of high stress, the roadway shape has little influence on the distribution of the principal stress difference of surrounding rock, but the equivalent excavation radius determines the distribution of the plastic zone of surrounding rock. The larger the ineffective reinforcement zone is, the larger the deformation around the roadway will be. The decrease of the angle between the structural plane and the vertical stress increases the failure range of the roadway under the gravity burst pressure. Under the horizontal tectonic stress type rock burst, when the structural plane inclination angle is 0°, the two-sided caving body fills the roadway and the roof caving range becomes smaller.

Supporting Numerical Simulation of Roadway Surrounding Rock in Deep High Stress Based on Broken-Expand Deformation

2013 ◽  
Vol 353-356 ◽  
pp. 1310-1314
Author(s):  
Wei Jian Yu ◽  
Yan Si Qu ◽  
Dai Qiang Deng
Keyword(s):  
Numerical Simulation ◽  
Large Deformation ◽  
High Stress ◽  
Stable State ◽  
Surrounding Rock ◽  
Stability Factor ◽  
Simulation And Optimization ◽  
Medium Length ◽  
Secondary Support ◽  
Primary Support

According to large deformation and supporting problem ofroadway surrounding rock under deep high stress caused by broken-expanddeformation, supporting numerical simulation and optimization on a roadway werestudied. Two primary support scheme of medium length anchor with self-drillinganchor and short pre-stressed anchor withself-drilling anchor and three secondary support scheme of 5m, 6mand 7m length cable were proposedbased on roadway engineering characteristics; Calculationparameters of support structureparameters and surrounding rock were determined based on broken-expanddeformation mechanism, and scheme were calculated respectively; Deformation, plasticzone and stable state of surrounding rock under different support were analyzedbased on results individually, and optimal support scheme were opted. Theresults showed that roadway used 5.5~6.0manchor cable as secondary support whose stability factor can be achieved 1.28could meet productive requirement.

The Surrounding Rock of Deep Borehole Pressure Relief and Let the Pressure Bolt Coupling Analysis

2013 ◽  
Vol 446-447 ◽  
pp. 1421-1424 ◽  
Author(s):  
Shu Guang Zhang ◽  
Long Chen ◽  
Hong Yu Jia
Keyword(s):  
Numerical Simulation ◽  
High Stress ◽  
High Strength ◽  
Surrounding Rock ◽  
Deformation Characteristics ◽  
Deep Borehole ◽  
Pressure Relief ◽  
High Strength Bolt ◽  
Supporting Effect ◽  
Coupling Support

Roadway borehole pressure relief and let the pressure anchor combined support technology were based on using the new pressure high strength bolt instead of ordinary bolt ,Combined with the borehole pressure relief principle, aim at releasing high stress of surrounding rock of roadway ,Complying with the deformation characteristics of supporting technology of the surrounding rock. In this paper, we used scaled numerical simulation technology —— ADINA to analyze the roadway borehole pressure relief and let the pressure anchor coupling support technology. To the tunnel, we used the method of numerical simulation of let the pressure bolt support independently, drilling pressure relief, and borehole pressure relief and let the pressure anchor coupling support three kinds of the comparison numerical simulation. The advantages of coupling supporting effect was elaborated, It was instructive for the deeply roadway engineering in the future.

scholarly journals Research on Hydraulic Fracturing Pressure Relief Technology in the Deep High-Stress Roadway for Surrounding Rock Control

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wen Zhai ◽  
Yachao Guo ◽  
Xiaochuan Ma ◽  
Nailv Li ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Hydraulic Fracturing ◽  
High Stress ◽  
Economic Benefits ◽  
Surrounding Rock ◽  
Pressure Relief ◽  
Deformation And Failure ◽  
Working Face ◽  
Roadway Stability ◽  
Surrounding Rock Control

With the increase of mining depth in underground engineering, deep ground pressure has an extremely unfavorable impact on safety production and the economic benefits of coal mines and the control of the roadway stability in deep mines are gradually highlighted. In this study, the working face 14203 of the Zaoquan coal mine was taken as the engineering background, the deformation mechanism of surrounding rock in the deep-buried high-stress roadway was analyzed, and the hydraulic fracturing pressure relief technology in the advanced roadway was proposed for surrounding rock control. Finally, the numerical simulation and field tests were used to validate the comprehensive effect of the proposed technology. Without damaging the roadway stability in the working face, the hydraulic fracturing pressure relief technology can optimize the stress environment and stability of the roadway through the artificial control of the roof fracture position. The numerical simulation shows that under the action of hydraulic fracturing, the cutting slot is formed, the deformation and failure mode of the roof are changed, the stress of surrounding rock is reduced, and the development of the plastic zone of surrounding rock is limited. As a result, the stability of surrounding rock in the roadway is effectively protected. The field test shows that after the adoption of hydraulic fracturing pressure relief technology, the roof subsidence, floor separation, bolt stress, and cable stress decrease, and the deformation of surrounding rock is reduced significantly. Therefore, hydraulic fracturing pressure relief technology is verified as an effective method to control the large deformation of the surrounding rock in the deep-buried roadway.

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