Study on Mine Pressure Behavior of Roadway in Highly Irregular Working Face in Daizhuang Coal Mine

2012 ◽  
Vol 256-259 ◽  
pp. 1443-1446
Author(s):  
Xing Lin Wen ◽  
Lin Hai Gao ◽  
Chuan Lei Li ◽  
Meng Meng Dong
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Mining Engineering ◽  
Deformation Characteristics ◽  
Working Face ◽  
Production Safety ◽  
Support Force ◽  
Mining Face ◽  
Important Significance

The irregular face mechanized mining is one of the difficult problems in the field of mining engineering. In this thesis, the roadways of 4324 extremely irregular face in DaiZhuang Mine were taken as research object. Through on-site mine pressure observation, the deformation characteristics of the surrounding rock and support force was analyzed. Next the mine pressure appeared rule of the roadways was study. This study benefited that the production of 4324 mining face went on wheels, at the same time, it had important significance to production safety of irregular working face with similar conditions.

scholarly journals Support design of main retracement passage in fully mechanised coal mining face based on numerical simulation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yalong Li ◽  
Mohanad Ahmed Almalki ◽  
Cheng Li
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Control Measures ◽  
Coal Face ◽  
Support Design ◽  
Working Face ◽  
Surrounding Rock Control ◽  
Mining Face ◽  
Mining Pressure

Abstract For the comprehensive mechanised coal mining technology, the support design of the main withdrawal passage in the working face is an important link to achieve high yield and efficiency. Due to the impact of mining, the roof movement of the withdrawal passage is obvious, the displacement of the coal body will increase significantly, and it is easy to cause roof caving and serious lamination problems, and even lead to collapse accidents, which will affect the normal production of the mine. In this paper, the mining pressure development law of the main withdrawal passage support under the influence of dynamic pressure is designed, the most favourable roof failure form of the withdrawal passage is determined, and the action mechanism and applicable conditions of different mining pressure control measures are studied. The pressure appearance and stress distribution in the final mining stage of fully mechanised coal face are studied by numerical simulation. The deformation and failure characteristics and control measures of roof overburden in the last mining stage of fully mechanised coal face are analysed theoretically. Due to the fact that periodic pressure should be avoided as far as possible after the full-mechanised mining face is connected with the retracement passage, some auxiliary measures such as mining height control and forced roof blasting are put forward on this basis. The relative parameters of the main supporting forms are calculated. The main retracement of a fully mechanised working face in a coal mine channel is put forward to spread the surrounding rock grouting reinforcement, reinforcing roof, and help support and improve the bolt anchoring force, the main design retracement retracement channels in the channel near the return air along the trough for supporting reinforcing surrounding rock control optimisation measures, such as through the numerical simulation analysis, the optimisation measures for coal mine fully mechanised working face of surrounding rock is feasible. Numerical simulation results also show that the surrounding rock control of fully mechanised working face of coal mine design improvements, its main retreat channel under the roof subsidence, cribbing shrank significantly lower, and closer, to better control the deformation of surrounding rock, achieved significant effect, to ensure the safety of coal mine main retracement channel of fully mechanised working face support.

scholarly journals Research and Application of Directional Roof Cutting and Pressure Releasing Technology for Retracement Channel of 3314 Working Face in Hexi Coal Mine

2021 ◽  
Author(s):  
Jindong Cao ◽  
Xiaojie Yang ◽  
Ruifeng Huang ◽  
Qiang Fu ◽  
Yubing Gao
Keyword(s):  
Coal Mine ◽  
High Stress ◽  
Surrounding Rock ◽  
Engineering Practice ◽  
Mine Pressure ◽  
Working Face ◽  
Geological Conditions ◽  
Cutting Effect ◽  
The Stability ◽  
Two Sides

Abstract The high stress of the surrounding rock of Hexi Coal Mine easily leads to severe deformation of the retracement channel and the appearance of the mine pressure during the retreat severely affects the stability of the roadway. In order to solve the above problems, a roadway surrounding rock control technology is proposed and tested. The bidirectional energy-concentrated tensile blasting technology is used to perform directional cutting to cut off the stress propagation path. Firstly, the deformation mechanism of the roof is analyzed by establishing the deformation mechanical model of the roof of the retracement channel. Then, according to the geological conditions of working face 3314 and theoretical calculation, the key parameters of roof cutting and pressure releasing of retracement channel are determined, and through the numerical analysis of its cutting effect, the length of cutting seam is 11.5m, and the cutting angle is 10°. Finally, a field test is carried out on the retracement channel of 3314 working face to verify the effect of roof cutting. The results show that the deformation of the retracement channel and the main roadway is very small. In the process of connecting the working face and the retracement channel, the maximum roof to floor convergence is 141mm, and the two sides convergence is 79mm. After the hydraulic support was retracted, the maximum roof to floor convergence of the surrounding rock is 37 mm, and the two sides convergence is 33mm. The roof cutting and pressure releasing of the retracement channel ensures the safe evacuation of the equipment and the stability of the main roadway. The cutting effect is obvious for the release of pressure, which is of great significance to engineering practice.

Analysis on Instability of Surrounding Rock in Gob-Side Entry Retaining with the Character of Soft Rock Composite Roof

2012 ◽  
Vol 524-527 ◽  
pp. 396-403 ◽  
Author(s):  
De Chuan Yang ◽  
Ming Zhong Gao ◽  
Yun Hai Cheng ◽  
Wu Sheng ◽  
Jia Sheng Chen
Keyword(s):  
Coal Mine ◽  
Soft Rock ◽  
Main Roof ◽  
Wide Distribution ◽  
Economic Security ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Working Face ◽  
Immediate Roof ◽  
Plastic Zones

The filling belt of gob-side entry retaining with the character of soft rock composite roof,deforms violently,affected by the fracture and rotation of the main roof,and is prone to instability.This essay,considering characteristecs of coal mine pressure behavior on -790m 1311 (1) working face ventilation roadway at DingJi coal mine in HuaiNan,puts forward structural mech -anics model of the key block of gob-side entry retaining,which is used to forecast the position of the fracture line of the main roof, and analyze the roof subsidence at the side of the filling belt;It applies FLAC and UDEC to simulate distribution of plastic zones of surrounding rock of gob-side entry retaining,and stress variation law of the immediate roof and the main roof along coal seam inclination.The results show that:stress concentration factor of the immediate roof on the filling belt is about 1.6,first decreasing and then increasing with increasing width of the filling belt,which indicates that reasonable width of the filling belt is 3.0 m in accordance with the requirement of economic security requirment. The filling belt has significantly wide distribution of the plastic zones,with its four corners obviously plasticized,and overlying strata above the filling belt at side of goaf suffering upward plasticization,which is the result of rotation of the main roof; Deform- ation instability of filling belt is mainly caused by fracture rotation of the main roof;Finally, the measures to reduce the instability of gob-side entry retaining with the character of soft rock comp- osite roof are put forward.

Research on Upper Limit Increased of Mining in Coal Mining Face

2015 ◽  
Vol 737 ◽  
pp. 846-850
Author(s):  
Yong Jun Li ◽  
Chen Li ◽  
Hao Sun ◽  
Hai Tao Xu
Keyword(s):  
Coal Mining ◽  
Coal Mine ◽  
Coal Pillar ◽  
Economic Benefits ◽  
Production Ratio ◽  
Working Face ◽  
Zone Development ◽  
Mining Face ◽  
North China Area ◽  
Important Significance

In order to guarantee the safety of the coal mine, needing to leave in reasonable waterproof safety coal pillar. Aiming at the working face 3311 of Xuchang coal mine, this article based on the analysis to the basis of factors for improving the mining limit, using UDEC numerical simulation, the regulations of coal mining under buildings, railways and water bodies and historical experience to analyze crack-production ratio of the working face, study the height of water flowing fractured zone development, designing test mining program. Through the upper mining limit to liberate 160000t coal resources and to gain the obvious economic benefits, which provide important significance for other similar coal mines in coal field of North China area.

scholarly journals Study on Anchor Cable instead of Single Hydraulic Prop Support in Advance Support of Deep Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Wenpeng Su ◽  
Boyang Zheng ◽  
Pengfei Jiang
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Field Monitoring ◽  
Surrounding Rock ◽  
Deformation Characteristics ◽  
Deep Mine ◽  
Decrease Rate ◽  
Anchor Cable ◽  
Working Face ◽  
Hydraulic Prop

In order to solve the problems of complicated advanced support process, high labor intensity, affecting the rapid advance of working face and the destruction of roof bolt (cable) by advance single hydraulic prop in ultra kilometer deep mine roadway, the deformation characteristics of roadway surrounding rock is analyzed. Taking the 27304 working face of Wanglou coal mine as the engineering background, numerical simulation, field monitoring, and theoretical calculation were used to analyze the deformation characteristics of roadway surrounding rock within the advanced influence range of 27304 working face. This paper puts forward the active advance support technology scheme, in which grouting anchor cable replaces the existing single hydraulic prop in the advance influence range of the working face in the ultra-kilometer deep mine, and observes and analyzes the deformation and failure characteristics of the surrounding rock of the working face advance roadway. The numerical simulation results show that in the advanced influence range of deep roadway, grouting anchor cable was used to replace the previous single hydraulic prop, and the vertical stress at both ends of the working face decreased by 15 MPa, with a decrease rate of 33.3%; the displacement of roadway roof, floor, and two sides decreased by 10 mm, 55 mm, and 20 mm, with a decrease rate of 40%, 68.75%, and 47.6%, respectively. The field monitoring results show that the roof separation is obviously improved after using grouting anchor cable as the active advance support scheme. It solves the problem of safe and efficient production faced by the ultra-kilometer deep shaft in Wanglou coal mine and provides theoretical and technical support for unmanned double roadway advance support under the condition of safe and efficient mining.

scholarly journals Characteristics of New Permanent Magnetic Eddy Current Drive System of the Scraper Conveyor

2021 ◽  
Author(s):  
shuang wang ◽  
Yongcun GUO ◽  
Deyong LI
Keyword(s):  
Eddy Current ◽  
Coal Mine ◽  
Mining Area ◽  
Current Drive ◽  
Drive System ◽  
Model Accuracy ◽  
Working Face ◽  
Scraper Conveyor ◽  
Mining Face ◽  
Motion Characteristics

Abstract This study provides a new permanent magnetic eddy current drive system to solve the ener-gy-saving drive problem of the scraper conveyor working under bad conditions, including overload startup, severe abrasion and pollution. Considering the practical conveying conditions of the scraper chain on a fully mechanised coal mining face, this study creates a mathematical model for the new permanent magnetic eddy current drive system of the scraper conveyor based on its characteristics and indicates the motion characteristics of the scraper chain driven by two wheels. This study verifies the model accuracy with a pre-startup technology depending on the scraper conveyor on the No. 12318 working face of the 8th coal mine in the West No. 1 mining area of the Pansan Coal Mine of the Huainan Mining Group. According to the results, the motion acceleration of the scraper chain based on the new permanent magnetic eddy current drive is lower than that of the scraper chain with a hydraulic coupler under the same running condition and load during startup and acceleration and declines by approximately 14.7%. Consequently, this can decline the startup impact due to the serious abrasion and frequent overload of the scraper chain working under bad conditions.

Applications of Carbon Dioxide Cannon Blasting on the Problem of Triangular Flap Top in Coal Mine Handling Mechanized Mining Face

2012 ◽  
Vol 256-259 ◽  
pp. 71-74
Author(s):  
Yan Bo Zhang ◽  
Er Qiang Li ◽  
Jia Wei Liu ◽  
Xin Jia Leng ◽  
Wen Guo Li
Keyword(s):  
Carbon Dioxide ◽  
Coal Mine ◽  
Effective Solution ◽  
Large Area ◽  
Triangular Flap ◽  
Production Safety ◽  
Mining Face

As mining process in the Mechanized mining face, making it easy come with flap top[1] along the the upward and downward entries. In this paper, through the use of carbon dioxide cannon, we do pre-split blasting experiment on triangular flap top in mechanized mining face, exploring an effective solution to a large area of goaf flap top suddenly breaking down, with the hurricane caused damage and fan-out of toxic and harmful gases, to achieve the purpose of production safety.

scholarly journals Prediction of the First Weighting from the Working Face Roof in a Coal Mine Based on a GA-BP Neural Network

2019 ◽  
Vol 9 (19) ◽  
pp. 4159
Author(s):  
Tan ◽  
Yang ◽  
Chang ◽  
Zhao
Keyword(s):  
Neural Network ◽  
Coal Mine ◽  
Bp Neural Network ◽  
Prediction Models ◽  
Initial Pressure ◽  
Mining Area ◽  
Mine Pressure ◽  
Mine Production ◽  
Production Safety ◽  
Matlab Programming

The accidents caused by roof pressure seriously restrict the improvement of mines and threaten production safety. At present, most coal mine pressure forecasting methods still rely on expert experience and engineering analogies. Artificial neural network prediction technology has been widely used in coal mines. This new approach can predict the surface pressure on the roof, which is of great significance in coal mine production safety. In this paper, the mining pressure mechanism of coal seam roofs is summarized and studied, and 60 sets of initial pressure data from multiple working surfaces in the Datong mining area are collected for gray correlation analysis. Finally, 12 parameters are selected as the input parameters of the model. Suitable back propagation (BP) and GA(genetic algorithm)-BP initial roof pressure prediction models are established for the Datong mining area and trained with MATLAB programming. By comparing the training results, we found that the optimized GA-BP model has a larger determination coefficient, smaller error, and greater stability. The research shows that the prediction method based on the GA-BP neural network model is relatively reliable and has broad engineering application prospects as an auxiliary decision-making tool for coal mine production safety.

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.

scholarly journals Mine Pressure Behavior Characteristics and Control Methods of a Reused Entry that Was Formed by Roof Cutting: A Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yajun Wang ◽  
Haosen Wang ◽  
Manchao He ◽  
Qi Wang ◽  
Yafei Qiao ◽  
...  
Keyword(s):  
Deformation Zone ◽  
Dynamic Pressure ◽  
Field Application ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Stress Increase ◽  
Severe Deformation ◽  
Working Face ◽  
Roof Deformation

Noncoal pillar mining with automatic formation of a roadway is a new coal mining method that is tailored to improve the coal resource recovery rate and reduce the investment in roadway tunneling. Using this proposed method, a reuse entry is formed by roof cutting instead of tunneling. In this paper, the S1201-II working face of the Ningtiaota Coal Mine was used as a case study. The stress distribution of surrounding rock and the roof deformation characteristics of the reused entry during the mining process of the second working face were studied through FLAC3D numerical simulations combined with field measurements. The results indicate that the zone close to the reused entry led to higher stress in advance. If this stress is superimposed with the lateral pressure of the adjacent mined working face, it will be more difficult to maintain the reused entry. In the engineering case study described here, the reused entry created a stress increase zone and a severe deformation zone in the range of 0–80 m in front of the working face, and its range was approximately 37.5% larger than an ordinary entry. The stress peak in the stress increase zone increased by approximately 34.7% over that of an ordinary entry. The maximum amount of deformation within the severe deformation zone increased by 94.4% over that of an ordinary entry. To properly control the surrounding rock stress and deformation of the reused entry, a dynamic pressure bearing support in front of the working face with adaptability to the large roof deformation and high support strength is proposed here. Field application results showed that the final roof deformation with the dynamic pressure bearing support can be satisfactorily controlled within 110∼130 mm. These findings can provide a reference for researchers and field engineering technicians when engaging in the support work of reused entry.

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