Measurement and Analysis for Gas Emission Characters in Fully Mechanized Caving Face

2013 ◽  
Vol 353-356 ◽  
pp. 2331-2336
Author(s):  
Xin Jian Li ◽  
Shou Song Guo ◽  
Jun He ◽  
Xiang Fan Mi
Keyword(s):  
Abutment Pressure ◽  
Coal Production ◽  
Coal Face ◽  
Gas Emission ◽  
Obvious Effect ◽  
Gas Concentration ◽  
Working Face ◽  
Measurement And Analysis ◽  
Working Resistance ◽  
The Relationship

According to the practical condition of 3401 fully mechanized caving face in Dayang coal mine, the relationship between strata behaviors, mining technology and stope gas emission are analyzed through real-time monitoring of the support working resistance, advance abutment pressure and gas concentration of working face. It shows that the change of working face abutment pressure has an obvious effect on the regularity of coal face gas emission. The crest value of gas emission falls behind periodic weighting, the lagging time is about one day. Other factors, like coal production processes, daily coal output and advance speed also have close relationships with gas emission.

scholarly journals Safe and Efficient Coal Mining Below the Goaf: A Case Study

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 864 ◽  
Author(s):  
Weidong Pan ◽  
Shaopeng Zhang ◽  
Yi Liu
Keyword(s):  
Abutment Pressure ◽  
Theoretical Calculations ◽  
Distribution Law ◽  
Working Face ◽  
Strata Behavior ◽  
Working Resistance ◽  
Behavior Characteristics ◽  
Theoretical Analyses ◽  
Important Significance

Mining at the fully mechanized working face below the goaf of the short-distance coal seam is influenced by the upper goaf. To address this problem, methods such as theoretical analyses, numerical simulation, and on-site measurement are used to study the strata behavior characteristics of the Ningxia Lingxin Coal Mine 051508 working face in this study. The roof weighting intervals of the working faces below the goaf and the non-goaf are obtained via theoretical calculations. The stoping processes of the working faces below the goaf and the non-goaf are simulated with FLAC3D to obtain the distribution law of the bearing pressure and plastic zones before the working face. Based on the statistical analysis of the measured working resistance of the supports and its distribution, the roof weighting interval of the working face mining below the goaf is obtained. The results show that the roof weighting interval and the advanced abutment pressure during mining at the working face below the goaf are smaller than those below the non-goaf, providing a reasonable theoretical basis for mining below the goaf, and having important significance for safe and efficient mining.

Research Foundation of Rock-Burst Hazard Control for Mining Pattern with No Pillar

2010 ◽  
Vol 156-157 ◽  
pp. 207-210
Author(s):  
Zhi Jie Wen ◽  
Lian Jun Chen ◽  
Xiao Dong Zhao ◽  
Chuan Zhang
Keyword(s):  
Rock Burst ◽  
Abutment Pressure ◽  
Relevant Information ◽  
Mechanics Model ◽  
Working Face ◽  
Hazard Control ◽  
Time Space ◽  
Relationship Of ◽  
The Relationship ◽  
Realization Condition

In order to effectively prevent the rock burst occurrence for mining patter with no pillar, the reason and its realization condition of rock burst were studied; the stope structure mechanics model with working face mining was built; four phases of rock burst occurrence with mining were proposed; the relationship between rock burst occurrence and abutment pressure law of development was analyzed, time-space coupling relationship of rock burst and its relevant information for rock burst control were obtained.

Determination Method of the Supporting Intensity of Fully-Mechanized Face in Deeply Inclined Medium-Thickness Seam

2014 ◽  
Vol 522-524 ◽  
pp. 1386-1389
Author(s):  
Zhong Ping Guo ◽  
Hui Qiang Duan ◽  
Fan Feng ◽  
Gui Yin Zhang
Keyword(s):  
Coal Seam ◽  
Theoretical Basis ◽  
Surrounding Rock ◽  
Medium Thickness ◽  
Working Face ◽  
Displacement Thickness ◽  
Face Length ◽  
Working Resistance ◽  
Theory Calculation ◽  
The Relationship

According to the occurrence conditions of deeply inclined coal seam of 81206 working face in Yanya coal mine, methods including transmission rock theory calculation and numerical calculation based on the relationship between supports and surrounding rock are used to calculate and analyze. The proper working resistance of support is 5979.2kN and the supporting intensity is 0.8~0.95MPa. The regression equation associated with roof subsidence displacement , thickness of the coal seam, working face length and supporting intensity is accomplished, which provides theoretical basis for the support selection.

Numerical Analysis on Ground Pressure Feature in Fully Mechanized Coal Face

2013 ◽  
Vol 807-809 ◽  
pp. 2299-2303
Author(s):  
Wei Jian Yu ◽  
Tao Feng ◽  
Gang Ye Guo
Keyword(s):  
Numerical Analysis ◽  
Abutment Pressure ◽  
Numerical Procedure ◽  
Wall Rock ◽  
Coal Face ◽  
Distribution Form ◽  
Ground Pressure ◽  
Working Face ◽  
Set Up ◽  
Mining Height

Base on the fully mechanized coal face of 8113 (1) in LaoYingSan mine, numerical analysis method was applied to analyze the ground pressure feature, FLAC software is carried out to set up numerical model, and offer numerical procedure. The mining abutment pressure distribute form and its partition in front of fully mechanized working face. All four different mining height (2.6m2.8m3.0m3.2m) was respectively calculated. In addition, the influence of mining speed to mining abutment pressure and intervals is analyzed, four different mining distance (20m30m40m50m) selected separately. Afterwards, the different solution analyzed respectively, these results show that the mining abutment pressure distribution form in front of fully mechanized working face essentially identical, they including the stress increasing zones, the stress decreasing zones and the initial rock stress stable field. The influence of mining pace to wall rock looseness range greater than mining height.

scholarly journals Study on Rock Burst Early Warning in the Working Face of Deep Coal Mines Based on the Law of Gas Emission

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Qinghua Zhang ◽  
Shudong He
Keyword(s):  
Rock Burst ◽  
Early Warning ◽  
Critical Value ◽  
Gas Emission ◽  
Distribution Law ◽  
Deep Mine ◽  
Gas Concentration ◽  
Research Results ◽  
Working Face ◽  
The Law

This study is aimed at predicting rock burst disasters in high gas mines. First, the distribution law and correlation of gas and stress in the F15-17-11111 working face of Pingdingshan No. 13 Mine were analyzed based on the coupling relationship between gas emission and stress in the working face. Next, the relationship between gas emission and stress distribution was revealed, and an early warning method of rock burst in the deep mine working face based on the law of gas emission was proposed and applied to the F15-17-11111 working face. Finally, the critical value of the gas concentration indicator for rock burst early warning in the F15-17-11111 working face was determined as 0.05%. The following research results were obtained. The gas emission and the mining stress in the F15-17-11111 working face are negatively correlated. Mechanically, their correlation satisfies the typical coupling. Besides, the critical value of the gas concentration indicator determined by the proposed early warning method boasts high accuracy in predicting rock burst disasters. It can be used as an early warning method for underground rock burst disasters to promote the safety of working face mining. The research results provide reference and guidance for the monitoring and early warning of rock burst disasters in deep high gas mines.

scholarly journals Dynamic Secondary Borehole-Sealing Method for Gas Drainage Boreholes along the Coal Seam

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Qin ◽  
Jialin Xu
Keyword(s):  
Abutment Pressure ◽  
High Water ◽  
Test Results ◽  
Gas Drainage ◽  
Gas Concentration ◽  
Working Face ◽  
Opportune Time ◽  
Sealing Device ◽  
Better Than

Under the influence of advanced abutment pressure, the tightness of a borehole is destroyed, so secondary borehole sealing is needed; however, the opportune time for a secondary borehole sealing is unclear. In addition, current borehole-sealing devices do not have a secondary borehole-sealing functionality. In this paper, an opportunity election model of secondary borehole sealing was established, and a dynamic secondary borehole-sealing device was developed. In working face 3908 of the Kaiyuan Coal Mine, an in situ dynamic secondary borehole-sealing test was conducted. The test results show that the tightness of the boreholes sealed with high-water-expansion slurry is obviously better than that of the boreholes sealed with cement mortar and polyurethane. When a borehole is destroyed by the peak of the advanced abutment pressure, the secondary borehole-sealing measures can significantly improve borehole suction pressure, gas concentration, and gas drainage amount in the advanced abutment pressure loading stage.

Analysis on the Influence Factors of Gas Emission in Eastern 113 Working Face of Dashuitou Mine

2012 ◽  
Vol 616-618 ◽  
pp. 426-430
Author(s):  
Zuo Quan Li ◽  
Yin Shang Wei ◽  
Liang Song Guo
Keyword(s):  
Atmospheric Pressure ◽  
Influencing Factor ◽  
Influence Factors ◽  
Gas Emission ◽  
Atmosphere Pressure ◽  
Working Face ◽  
Sensitive Factor ◽  
Pressure Changes ◽  
The Relationship ◽  
Grey Correlation Theory

There are many factors that affect the gas emission in working face. To predict and prevent this kind of gas emission, the mainly sensitive factor should be filtered and detected from many influencing factors. Taken Dashuitou Mine for an example, the main influencing factor was analyzed by using Grey correlation theory, which was atmosphere pressure. Then, the relationship between atmosphere pressure and gas emission is studied with Statistics tools. It obtained some important conclusions, include the rule of Atmospheric pressure changes in working face during a day, rule of the gas underground changes in a day, rule of correlation statistical, concrete relation between atmospheric pressure and gas emission. It would be useful on disposing of gas emission risk.

scholarly journals The Law of Fracture Evolution of Overlying Strata and Gas Emission in Goaf under the Influence of Mining

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Cheng Cheng ◽  
Xiaoyu Cheng ◽  
Rui Yu ◽  
Wenping Yue ◽  
Chao Liu
Keyword(s):  
Maximum Height ◽  
Gas Migration ◽  
Gas Emission ◽  
Pressure Relief ◽  
Gas Concentration ◽  
Fracture Evolution ◽  
Working Face ◽  
Simulation Results ◽  
The Law ◽  
Overlying Strata

Mining is associated with poor safety due to pressure relief gas emission from the goaf during the production period. The aim of this study was to explore a case study of the Wangjialing coal mine 12322 working face in Shanxi, China, through physical simulation and field observation. The mine is characterized by overlying strata fracture in goaf during the process of working face mining. A mathematical model of gas source emission from the working face and gas migration and the finite element COMSOL software were used to simulate the law of gas migration in the region with overlying strata fissures under the influence of mining. The simulation results were used to explore the law of distribution of pressure relief gas in goaf. Rational parameters of the high-level directional long borehole for the pressure relief gas extraction in goaf were designed based on experimental results. The results showed that the development of the region with overlying strata fissures is affected by mining. In addition, the “trapezoid platform structure” is formed after fracture areas are connected. The maximum height of the stope caving zone was between 26.8 m and 28.1 m, and the maximum height of the fracture zone was approximately 110 m. The gas concentration exhibited a saddle-shaped distribution on the cut surface of the direction of the strike. Furthermore, the gas concentration showed an overall upward trend from the intake airflow roadway to the return airflow roadway and gradually decreased after reaching the maximum. In the vertical direction, gas concentration increased with the increase in the layer, and the position of the highest point of gas concentration gradually shifted to the direction of the intake airflow roadway. Construction parameters of the high directional long borehole were designed through simulation results. After steady extraction and stable extraction, the maximum gas concentration in the upper corner of the working face was 0.49%, and the maximum gas concentration in return airflow was 0.34%. The findings of this study provide information on the law of fracture evolution of overlying strata and gas migration in goaf under the influence of mining. These findings provide a basis for reducing gas overlimit in the working face or return airway corner, thus improving the safety production capacity of the coal mine.

scholarly journals Comprehensive Control Method of Gas in Upper Corner of High Strength Fully Mechanized Coal Mine

2021 ◽  
Vol 233 ◽  
pp. 01009
Author(s):  
Huijun Duan ◽  
Shijun Hao ◽  
Xu Peng
Keyword(s):  
Coal Mine ◽  
Control Method ◽  
High Strength ◽  
Gas Content ◽  
Engineering Practice ◽  
Directional Drilling ◽  
Gas Emission ◽  
Gas Concentration ◽  
Working Face ◽  
Mining Face

Based on the problem of large gas emission and serious gas accumulation in upper corner of the intensive fully mechanized caving face, taking the fully mechanized caving face of Wangjialing Coal Mine in Hedong Mine as the research object, the main gas emission sources of the extremely intensive mining face with low permeability and low gas content were studied. The methods of gas extraction by inserting (burying) pipe in upper corner and directional drilling in upper corner were adopted and carried out. The application of engineering practice and comparative test of effect are carried out. The results show that the maximum extraction purity is 2.8 m³/min, the maximum gas concentration is 0.8% in upper corner, 3.11 m³/min in the high directional borehole and 0.71% in upper corner. After combined extraction, the total extraction purity is 1.33~7.93 m³/min and the fluctuation range of gas concentration in upper corner is reduced to 0.31~0.61% safe point. The effect of gas prevention and control in working face is remarkable.

scholarly journals Effect of Face Length in Initial Mining Stage of Fully Mechanized Top-coal Caving Face With Large Mining Height

2021 ◽  
Author(s):  
Jianhang Wang ◽  
Yao Lu ◽  
CHANGXIANG WANG ◽  
Guangwei Xu ◽  
Chengran Zhang
Keyword(s):  
Mine Pressure ◽  
Pressure Behavior ◽  
Working Face ◽  
Face Length ◽  
The Face ◽  
Large Mining Height ◽  
Strata Behavior ◽  
Working Resistance ◽  
The Relationship ◽  
Surface Length

Abstract Based on the field measurement of the end resistance of the support during the initial weighting of the basic roof and the macroscopic mine pressure behavior during the weighting period of 101,22211,103 and 301 fully mechanized caving face in Changchun Xing Coal Mine, the mine pressure law of the working face is summarized and compared, and the relationship between the working face length and the working resistance of the support ( the weighting strength ) and the macroscopic mine pressure behavior is obtained. In the range of face length 126-230 m, with the increase of face length, the end-of-cycle resistance of the support gradually increases and the dynamic load coefficient of the support gradually increases when the coefficient of the support gradually increases, and the strata behavior of the working face changes from strong to very strong. When the face length is short ( 126-140.5m ), the hanging top area is too large to cause hurricanes when the working face is pressed, which threatens and damages the personal safety and equipment of the working face staff. Based on the above research, the problem of optimizing the surface length is proposed, and the surface length is determined to be within the range of 140-230 m according to the measured results.

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