Surrounding Rock Convergence Rule along the Working Face Tendency of Recovery Room

2014 ◽  
Vol 962-965 ◽  
pp. 352-356
Author(s):  
Zhigang Wu ◽  
Wen Zhou Li
Keyword(s):  
Stress Distribution ◽  
Recovery Room ◽  
Coal Pillar ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Working Face ◽  
Deformation Mechanics ◽  
Surrounding Rock Deformation ◽  
Moving Speed

Recovery room could ensure the returning safety of working face equipment, improve mining and moving speed efficiency. Surrounding rock of working face will be distributed after recovery room driving, surrounding rock convergence drastically, and mining influence surrounding rock of recovery room also. Stress distribution around recovery room complex. Surrounding rock deformation rule along tendency of working face was studied by filed measurement in Sihe cola mine of the Jincheng coal district in China. It reveals surrounding rock deformation mechanics during coal pillar of working face through.

scholarly journals Surrounding rock deformation and stress evolution in pre-driven longwall recovery rooms at the end of mining stage

2019 ◽  
Vol 6 (4) ◽  
pp. 536-546 ◽  
Author(s):  
Bonan Wang ◽  
Faning Dang ◽  
Wei Chao ◽  
Yanping Miao ◽  
Jun Li ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Recovery Room ◽  
Coal Pillar ◽  
Main Roof ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Stress Evolution ◽  
The Face ◽  
Surrounding Rock Deformation

Abstract Two case studies were conducted in the Shennan mining area of Shaanxi Province, China to evaluate the surrounding rock deformation and stress evolution in pre-driven longwall recovery rooms. These studies mainly monitored the surrounding rock deformation and coal pillar stress in the recovery rooms of the N1206 panel of 2−2 coal seam at Ningtiaota Coal Mine and the 15205 panel of 5−2 coal seam at Hongliulin Coal Mine. The monitoring results showed that the surrounding rock deformation of the main recovery room and the coal pillar stress in the N1206 and 15205 panels began to increase significantly when the face was 36 m and 42 m away from the terminal line, respectively. After the face entered the main recovery room, the maximum roof-to-floor convergence in the N1206 and 15205 panels was 348.03 mm and 771.24 mm, respectively, and the coal pillar stresses increased more than 5 MPa and 7 MPa, respectively. In addition, analysis of the periodic weighting data showed that the main roof break position of the N1206 and 15205 panels after the longwall face entered the main recovery room was − 3.8 m and − 8.2 m, respectively. This research shows that when the main roof breaks above the coal pillar, the surrounding rock deformation of the main recovery room and the coal pillar stress increase sharply. The last weighting is the key factor affecting the stability of the main recovery room and the coal pillar; main roof breaks at disadvantageous positions are the main cause of the support crushing accidents.

scholarly journals Study on strata behavior law of deep inclined coal seam

2021 ◽  
Vol 248 ◽  
pp. 03031
Author(s):  
Chen Zhengwen
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Coal Seams ◽  
Working Face ◽  
Support Resistance ◽  
Strata Behavior ◽  
The Law ◽  
Surrounding Rock Deformation

In order to understand and grasp the law of roof pressure on the working face of deep inclined coal seams, the law of support resistance distribution, the law of leading support stress distribution and the law of surrounding rock deformation of the two roadways, the 94101 working face of Zhangshuanglou Coal Mine was taken as the engineering background. Through a combination of field measurement, numerical simulation, theoretical analysis, etc, this paper analyzes the laws of roof migration and rock pressure manifestation in deep inclined coal seams.

scholarly journals Research on Failure Mechanism and Strengthening of Broken Roadway Affected by Upper Coal Pillar

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Fulian He ◽  
Zheng Zheng ◽  
Hengzhong Zhu ◽  
Bo Yang
Keyword(s):  
Stress Distribution ◽  
Failure Mechanism ◽  
Coal Pillar ◽  
Control Area ◽  
Surrounding Rock ◽  
Horizontal Line ◽  
Protective Function ◽  
Working Face ◽  
Coal Pillars ◽  
Roadway Deformation

The principal stress difference is introduced as a new evaluation index in order to better understand the failure mechanism of roadways affected by upper coal pillars and characterize failure of rock mass. Compared with traditional methods, it facilitates quantitative analysis. Moreover, we combine the semiplane theory and we obtain the stress distribution on the coal pillar’s bedrock and the strengthening control area from the “change point” position along a 21 m horizontal line. The influence of multiple stresses induced from mining on a roadway is analyzed. It is found that rock failure is most likely while mining the 051606 working face, followed by mining the 051604 working face, and the stress influence on the upper pillar has the lowest failure probability. In addition, based on the asymmetry of the surrounding rock stress distribution, this study proposes strengthening control technology of surrounding rock on the basis of a highly stressed bolting support and anchor cable, adding to the steel ladder beam, steel mesh, and shed support’s protective function to the roadway’s roof and ribs. Finally, through field observations, it is concluded that the roadway deformation is within the controllable range.

scholarly journals Instability Analysis and Reinforcement Support Technology of Coal-Rock Interbed Roadway in Gaojiazhuang Coal Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chaolin Liu ◽  
Guohua Zhang
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Distribution Characteristics ◽  
Control Effect ◽  
Ultrasonic Detection ◽  
Wide Range ◽  
Surrounding Rock Deformation

In order to effectively solve a series of problems such as the difficulty of coal and rock interbed roadway support in Gaojiazhuang Coal Mine and get a scientific and reasonable optimization scheme of surrounding rock support, theoretical analysis, numerical simulation, ultrasonic detection, field-effect test, and other means are adopted to analyze the instability of coal and rock interbed roadway. The results show that the interbedded roadway has weak interbedded cementation, and its ore pressure is more intense due to the influence of its interbedded weak structural plane. Based on Mohr’s strength envelope principle, it is proposed that horizontal stress is the main factor that causes a wide range of shear displacement, penetration crack, and surrounding rock failure of the roof of this kind of roadway. Through the finite element numerical simulation analysis, the deformation and failure law, stress distribution characteristics, and failure area distribution characteristics of coal and rock interbedding roadway surrounding rock are theoretically revealed, and the control effect of different support schemes on roadway surrounding rock deformation is greatly different. Based on the ultrasonic detection technology, it is proved that the roadway side failure has strong zoning characteristics, and the failure range and stress distribution range of the surrounding rock of the belt roadway in the 2103 working face of Gaojiazhuang Coal Mine are detected. Finally, the coupling strengthening support scheme combining prestressed anchor cable and bolt is proposed. The engineering application and the observation of surrounding rock deformation show that the reinforced support technology can effectively enhance the stability of the surrounding rock of the interbed roadway in Gaojiazhuang Coal Mine, and it has a good reference for the surrounding rock conditions of this kind of roadway.

scholarly journals Research on the Stress Distribution Law of Fully Anchored Bolt and Analysis of Influencing Factors under the Condition of Surrounding Rock Deformation

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Chengxing Zhao ◽  
Yingming Li ◽  
Gang Liu ◽  
Dengguo Chen ◽  
Xiangrui Meng
Keyword(s):  
Stress Distribution ◽  
Interaction Model ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Rock Properties ◽  
Distribution Law ◽  
Rock Interaction ◽  
Deep Mine ◽  
Basic Work ◽  
Surrounding Rock Deformation

As the mining depth increases, the deformation of the roadway becomes more difficult to control. As a main supporting structure for maintaining the stability of roadway, the fully anchored bolt is widely used to reinforce deep mine. At the same time, the analysis of the stress distribution law of fully anchored bolt is the basic work to optimize anchor design. Therefore, this paper establishes a fully anchored bolt-surrounding rock interaction model based on the law of surrounding rock deformation and derives the analytical expressions for the axial force and shear stress of the fully anchored bolt during normal support and critical failure. At the same time, the effects of surrounding rock properties, support resistance, and bolt length on the stress distribution of fully anchored bolt are analyzed. The results show that the stress distribution of fully anchored bolt is consistent with the “neutral point” theory and the most important is the fact that the conditions of surrounding rock, the supporting resistance, and the length of bolt affect the actual stress distribution of the fully anchored bolt. It provides a certain theoretical basis for the design and development of anchoring and supporting technology.

scholarly journals Analysis of Influence Law of Burial Depth on Surrounding Rock Deformation of Roadway

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Hai Wu ◽  
Xiaokang Wang ◽  
Weijian Yu ◽  
Weijun Wang ◽  
Zizheng Zhang ◽  
...  
Keyword(s):  
Surrounding Rock ◽  
Rock Deformation ◽  
Burial Depth ◽  
Monitoring Point ◽  
Working Face ◽  
Different Depths ◽  
Roadway Deformation ◽  
Two Stages ◽  
Surrounding Rock Deformation ◽  
Deformation Increment

In order to study the influence of burial depth on the roadway deformation, the deformation data of more than 100 roadways were collected and classified. The results have shown that, in the first 5 days of new digging roadways, the surrounding rock deformation is basically not affected by the buried depth. The influence period of roadway deformation with different depths is the same, namely, the severe period (1∼15 days), the mitigation period (15∼35 days), and the stable period (35∼50 days). With the increase in depth, the surrounding rock deformation increment of new digging roadways with a depth of 300∼600 m is much larger than that of 600∼900 m. Within 100 m of the working face from the monitoring point, the deformation of mining roadways can be divided into two stages: severe impact (10∼60 m) and stable impact (60∼100 m). With the increase in depth, the deformation increment of the surrounding rock in the mining roadways with a depth of 600∼900 m is much larger than that of 300∼600 m. The surrounding rock deformation increases with the increase in the width and height of roadways and gradually increases with the decrease in the strength of rock mass.

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