scholarly journals Research of the Surrounding Rock Deformation Control Technology in Roadway under Multiple Excavations and Mining

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Ming Su ◽  
Xiaohui Gao
Keyword(s):  
Coal Mine ◽  
Reference Value ◽  
Field Investigation ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Effect ◽  
Deformation Control ◽  
Bolt Stress ◽  
Advanced Support ◽  
Surrounding Rock Deformation

To effectively control the large surrounding rock deformation of the mining roadway under multiple excavations and mining in Wangcun coal mine, the field investigation, numerical simulation, field test, and monitoring were conducted, and the characteristics of stress and deformation evolution of the surrounding rock under the influence of multiple excavations and mining were analyzed; then the collaborative supporting technology of high prestressed bolt and short anchor cables was proposed in this study. The results show the following: (1) under the influence of multiple excavations and mining, the peak vertical stress of the typical air-return roadway reaches 23 MPa, and the deformation increases by about 2.8 times after the mining of adjacent panel. (2) The principle of the roadway support under the influence of multiple excavations and mining in Wangcun coal mine is determined; from the perspective of prestress, we can conclude that the active support of short anchor cables is better than that of long anchor cables. (3) Based on the results of the field monitoring, the bolt stress can be divided into four stages: the loss stage of prestress, the sudden-decrease stage of the roof periodic weighting, the decrease stage of advanced support, and the rapid-increase stage of strong disturbance. Due to the large anchorage range of anchor cables, there is no decrease stage of advanced support. After the application of prestress, the bolt stress of side bolts and top bolts decreases, and the reduction amplitude is up to 30 kN. (4) As the panel advances, the deformation of the surrounding roadway increases, and the growth rate is also increasing gradually. However, the final displacement of the roof, floor, and two sides is within 18 mm. The bolt and anchor cables are not broken, and the control effect is good. The research results have a certain reference value for similar roadway control.

scholarly journals Application of Distributed Optical Fiber Sensing Technology in Surrounding Rock Deformation Control of TBM-Excavated Coal Mine Roadway

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Bin Tang ◽  
Hua Cheng
Keyword(s):  
Optical Fiber ◽  
Coal Mine ◽  
Time Domain Reflectometry ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Deformation And Failure ◽  
Deformation Control ◽  
Monitoring Techniques ◽  
Deformation Behaviors ◽  
Surrounding Rock Deformation

After roadway excavation, the deformation and failure of roadway surrounding rocks typically results in roadway damage or collapse. Conventional monitoring techniques, such as extensometers, stress meters, and convergence stations, are only capable to detect the stress or strain data with the shallow layers of surrounding rocks, and they require arduous manual works. Moreover, in the abovementioned monitoring techniques, the monitoring instruments are installed behind the excavation face; therefore, the strain and deformation occurring in front of excavation face cannot be detected. In order to eliminate these shortcomings, an innovative monitoring system for surrounding rock deformation control has been developed base on Brillouin optical time domain reflectometry. Compared with conventional monitoring systems, the proposed system provides a reliable, accurate, and real-time monitoring measure for roadway surrounding rock deformation control over wide extension. The optical fiber sensors are installed in boreholes which are situated ahead of the excavation face; therefore, the sensors can be protected well and the surrounding rock deformation behaviors can be studied. The proposed system has been applied within a TBM-excavated roadway in Zhangji coal mine, China. The surrounding rock deformation behaviors have been detected accurately, and the monitoring results provided essential references for surrounding rock deformation control works.

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 STUDY ON INTENSIVE DESIGN AND CONTROL OF CHAMBER GROUP UNDER THE CONDITION OF WEAK SURROUNDING ROCK

Mining Scince ◽  
2019 ◽  
Vol 26 ◽  
Author(s):  
Jun Yang ◽  
Shilin Hou ◽  
Kaifang Zhou ◽  
Bowen Qiao ◽  
Hongyu Wang ◽  
...  
Keyword(s):  
Stability Control ◽  
Field Application ◽  
Surrounding Rock ◽  
Control Measures ◽  
Wire Mesh ◽  
Rock Deformation ◽  
Control Effect ◽  
Obvious Effect ◽  
And Control ◽  
Surrounding Rock Deformation

In order to study the design and stability control of deep soft rock chamber group, taking ninth coal mine of Hebi Coal Power Co., Ltd. as the engineering background, The main problem in normal design is analyzed with the combined method of FLAC3D numerical simulation and field engineering test. and then puts forward targeted control measures and carries out field application. The results show that, compared with the conventional design, the intensive design can reduce the stress concentration degree and plastic zone range of the surrounding rock, as well as reduce the quantities. Compared with conventional supporting schemes, the surrounding rock deformation greatly reduces by more than 82% after adopting bolting and shotcreting with wire mesh + anchor cable + floor anchor supporting. Among them, the floor heave control has obvious effect, and the decreasing amplitude reaches more than 93%. The field application shows that the surrounding rock deformation of the main chamber is within the allowable range, and the chamber control effect is good. Therefore, the research results can provide reference for the design and control of similar chamber groups.

scholarly journals Surrounding rock deformation control of asymmetrical roadway in deep three-soft coal seam: a case study

2018 ◽  
Vol 15 (5) ◽  
pp. 1917-1928 ◽  
Author(s):  
Wei Zhang ◽  
Ziming He ◽  
Dongsheng Zhang ◽  
Dahong Qi ◽  
Weisheng Zhang
Keyword(s):  
Coal Seam ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Deformation Control ◽  
Soft Coal ◽  
Soft Coal Seam ◽  
Surrounding Rock Deformation

scholarly journals Support Technology of Long Bolt in Roadway under Crushing Condition

2020 ◽  
Vol 194 ◽  
pp. 04037
Author(s):  
Sang Pengde
Keyword(s):  
Industrial Test ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Effect ◽  
Deformation Method ◽  
Anchor Cable ◽  
Deformation State ◽  
Support Resistance ◽  
Effect Of Support ◽  
Surrounding Rock Deformation

In order to solve the problem that the roadway roof is large and easy to collapse under crushing conditions. Test shows that: Under the crushing condition, a considerable part of roadway surrounding rock deformation is in a given deformation state. The control effect of support resistance on surrounding rock deformation is limited at the level of existing technology. In this kind of roadway support, the deformation method of anchor cable high rigidity support should be abandoned. It is changed to adopt the long bolt with high elongation to adapt to the deformation of surrounding rock, and continue to provide high support resistance to prevent loose rock caving caused by roof collapse. Based on this, the supporting technology of replacing anchor cable with docking bolt is put forward to increase the coordination between supporting member and roadway surrounding rock deformation. The industrial test results of Baode coal mine show that the technology can adapt to the deformation of surrounding rock and effectively prevent the tunnel roof from caving due to the break of anchor cable.

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 the Instability Characteristics and Bolt Support in Deep Mining Roadways Based on the Surrounding Rock Stability Index: Example of Pansan Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  
Keyword(s):  
Coal Mine ◽  
Stability Index ◽  
Surrounding Rock ◽  
Full Length ◽  
Control Effect ◽  
Support Design ◽  
Rock Stability ◽  
Working Face ◽  
The Stability ◽  
Bolt Support

In view of the influence of mining stress on the stability of the surrounding rock of inclined roof mining roadways in deep mines, the surrounding rock stability index is defined and solved based on the rock strength criterion and the stress distribution. The mining roadway of the 17102(3) working face of the Pansan Coal Mine is used as the engineering background and example. The surrounding rock’ stabilities under the conditions of no support and bolt support are analyzed according to the surrounding rock’s stability index and the deformation data. The results show that the areas of low wall and high wall instability are 1.68 m2 and 2.12 m2, respectively, and the low wall is more stable than the high wall; the areas of the roof and floor instability are 0.33 m2 and 0.35 m2, respectively, and the roof and floor are more stable than the two sides. During mining, the area of instability greatly increases at first, then decreases to 0, and reaches a maximum value at the peak of the abutment pressure. The stability of the surrounding rock decreases first and then increases. Compared with the end anchoring bolt support, the full-length anchoring bolt support reduces the area of instability to a greater extent, and the full-length anchoring bolt support effect is better. The surrounding rock in the end anchoring zone and the full-length anchoring zone began to deform significantly at 200 m and 150 m from the working face, respectively. This indicates that the control effect of the full-length anchoring bolt support is better and verifies the rationality of the surrounding rock stability index to describe the instability characteristics. This research method can provide a theoretical reference for analysis of the stability characteristics and support design of different cross-section roadways.

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