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.

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.

Study on the Relationship between Hydraulic Support on the Working Face with Large Mining Height and Surrounding Rock

2011 ◽  
Vol 328-330 ◽  
pp. 1671-1674
Author(s):  
Ying Ma ◽  
Sheng Zhong
Keyword(s):  
Coal Seam ◽  
Surrounding Rock ◽  
Hydraulic Support ◽  
Working Face ◽  
Safety Work ◽  
Immediate Roof ◽  
The Face ◽  
Large Mining Height ◽  
The Relationship ◽  
Mining Height

Using unified model and theory of rock pressure, the problems, such as caving of stope roof with large mining height and destruction of support, strata movement and surface subsidence, are unified analyzed and researched. The results show that: pressure shell is dynamic shell, which moves forward with the propulsion of working face; with the increase of mining height on the face, the height of fracture zone in coal seam increases, not continuously, but jumpily; with the increase of mining height, support load rises, but the degree of this rise decreases gradually, increased degree of immediate roof weight should be greater than that of given deformation pressure. The results provide necessary basis for reliability of hydraulic support on the working face with large mining height and safety work in the underground.

Numerical Simulation of Strata Behavior in Super-Long and Large Mining Height Working Face

2013 ◽  
Vol 634-638 ◽  
pp. 3428-3432 ◽  
Author(s):  
Zhi Hua Li ◽  
Xin Zhu Hua ◽  
Ruo Jun Zhu ◽  
De Sheng Zhou
Keyword(s):  
Abutment Pressure ◽  
Roof Displacement ◽  
Mining Depth ◽  
Working Face ◽  
Face Length ◽  
Coal Wall ◽  
Large Mining Height ◽  
Strata Behavior ◽  
Behavior Characteristics ◽  
Mining Height

In order to study the strata behavior characteristics in super-long and large mining height working face, the FLAC-3D software was used to study the roof displacement and the abutment pressure distribution laws of working faces. The results indicate that: ① the influence range is larger of front abutment pressure in Liuzhuang coal mine 171301 super-long large mining height working face, and reaches to 60m. ② the maximum roof displacement increases with the increase of mining depth and working face length, the increase in magnitude decreases gradually, while the maximum roof displacement sharply increases due to the increase of mining height. ③ the peak abutment pressure increases with the increase of mining depth and mining height, the location of peak abutment pressure transfer to ahead of the coal wall. ④ the effect of working face length on abutment pressure is very feeble, so, the strata behavior characteristics remain almost constant with the increase of face length.

The Three-Dimensional Similar Simulation of Stress Regular Pattern of Roof of Large Mining Height

2014 ◽  
Vol 945-949 ◽  
pp. 1190-1195 ◽  
Author(s):  
Xiao Tao Zeng ◽  
Ning Wang ◽  
Cong Jiang ◽  
Yun Yi Zhang ◽  
Gang Chen
Keyword(s):  
Three Dimensional ◽  
Mining Area ◽  
In Situ Stress ◽  
Stimulation Test ◽  
Mine Pressure ◽  
Pressure Behavior ◽  
Working Face ◽  
Large Mining Height ◽  
Roadway Deformation ◽  
Mining Height

Based on the distribution of in-situ stress and the special conditions of the large mining height in one mining area, the author conducted the analogy stimulation test of the mine pressure behavior and the roadway deformation law. This research, mainly based on the geographical conditions of 1 to 2 coal seam of this mining area, stimulated the mine pressure behavior of the working face and the roadways, as the mining height is 5meters and 6meters. Through this analogy stimulation test, the mine pressure behavior of working face, in the mining process with large mining height, is analyzed and summarized.

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.

Optimization Study of Advance Support in the Roadway of Paste Filling Working Face

2011 ◽  
Vol 255-260 ◽  
pp. 3702-3707
Author(s):  
Shao Jie Chen ◽  
Wei Jia Guo ◽  
Hai Long Wang ◽  
Bo Li
Keyword(s):  
Working Face ◽  
Optimization Study ◽  
Coal Wall ◽  
The Face ◽  
Strata Behavior ◽  
Behavior Characteristics ◽  
Working Efficiency ◽  
Practical Measure ◽  
Main Influence ◽  
Overlying Strata

On the basis of the field measurement, the characteristics of advance strata behavior are analyzed in the past filling working face and the advance support method is optimized in the roadway. The practical measure researches show that, because the paste filling supports the overlying strata of the goaf availably, the strata behaviors of 2351 paste filling working face in Daizhuang coalmine are not obvious; And the protective pillar bears a little load, The strata behaviors in non-production side are smaller than that in production side. The overlying strata gravity mainly acts on the coal wall in front of the face and the paste filling in the goaf. The value and main influence range of advance stress in front of the face is quite small and the main influence range is less than 15m. According to the advance strata behavior characteristics of the paste filling working face, the advance support of the track roadway is changed from 3 rows to 2 rows. And the support length of each row reduces from 20m to 15m. The advance support after optimizing can reduce the labor intensity greatly and improve the working efficiency of backfill mining.

Study on the Structure Characteristics and Ground Pressure Behavior of Overlying Strata with Shallow Buried Coal Seam

2011 ◽  
Vol 255-260 ◽  
pp. 3780-3785 ◽  
Author(s):  
Lei Yu ◽  
Zhi Zhong Fan ◽  
Gang Xu
Keyword(s):  
Coal Seam ◽  
Ground Subsidence ◽  
Mine Pressure ◽  
Structure Characteristics ◽  
Pressure Behavior ◽  
Ground Pressure ◽  
Working Face ◽  
Periodic Pressure ◽  
Seam Mining ◽  
Overlying Strata

The mine pressure behavior characters of shallow buried coal seam differed from both shallow seam mining and general depth seam. Mine pressure observation and numerical analysis were applied to research mine pressure behavior laws in fully mechanized face of shallow buried coal seam with thick bedrock and thin alluvium. It showed that the ground subsidence level phenomenon did not appear obviously although with obvious dynamic loading of fully mechanized face during the pressure period. The appearance was due to non-synchronized fracture from two key layers in the overlying rock layers and their interaction, which leaded to roof breaking initially and caving rocks with the form of an arch. Due to the periodic breaking and caving characteristics appearing as fully cut-down and arch alternately, the periodic pressure of shallow buried coal seam face showed as different size. The conclusion could be a reference for similar working face control.

scholarly journals Control of Gob-Side Roadway with Large Mining Height in Inclined Thick Coal Seam: A Case Study

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xie Fuxing
Keyword(s):  
Numerical Simulation ◽  
Coal Pillar ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Thick Coal Seam ◽  
Working Face ◽  
Rock Structure ◽  
Large Mining Height ◽  
Mining Height

The gob-side roadway of 130205, a large-mining-height working face in the Yangchangwan coal mine, was investigated in terms of the mine pressure law and support technology for large mining heights and narrow coal pillars for mining roadways. The research included field investigations, theoretical analysis, numerical simulation, field tests, and other methods. This paper analyzes the form of movement for overlying rock structure in a gob-side entry with a large mining height and summarizes the stress state and deformation failure characteristics of the surrounding rock. The failure mechanism of the surrounding rock of the gob-side roadway and controllable engineering factors causing deformation were analyzed. FLAC3D numerical simulation software was used to explore the influence law of coal pillar width, working face mining height, and mining intensity on the stability of the surrounding rock of the gob-side roadway. Ensuring the integrity of the coal pillar, improving the coordination of the system, and using asymmetric support structures as the core support concept are proposed. A reasonably designed support scheme for the gob-side roadway of the working face for 130205 was conducted, and a desirable engineering effect was obtained through field practice verification.

Study on Surface Subsidence and Separation Range Thick Seam Mining of Daping Mine

2013 ◽  
Vol 742 ◽  
pp. 268-271 ◽  
Author(s):  
Meng Lin Xu ◽  
Xun Guo Zhu ◽  
De Shen Zhao
Keyword(s):  
Surface Subsidence ◽  
Thick Seam ◽  
Working Face ◽  
Single Face ◽  
High Efficient ◽  
Mining Conditions ◽  
Face Length ◽  
The Face ◽  
Residual Space ◽  
Seam Mining

In order to study the surface subsidence and separation range features during the mining process in in thick seam mining of Daping mine , it takes the typical coal of mining in S2S9 face of Daping Mine, using the resemble simulation to study on it. The study showed that the subsidence amounted to less than the maximum under the geological and mining conditions, In the single-face mining conditions, when the face length is generally not more than (1/3-1/4) H.The mining thickness cannot deflection in the form completely transmitted to the surface, but abound in overburden bed rock mass formed within the fracture and caving into the residual space. This research can be a reference for safety and high efficient coal mining of other working face in Daping Coal Mine.

scholarly journals Roof Fracture Characteristics and Strata Behavior Law of Super Large Mining Working Faces

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Guozhen Zhao ◽  
Baisheng Zhang ◽  
Lihong Zhang ◽  
Chao Liu ◽  
Shuai Wang
Keyword(s):  
High Efficiency ◽  
High Strength ◽  
Step Length ◽  
High Yield ◽  
Rock Stratum ◽  
Fracture Characteristics ◽  
Working Face ◽  
Large Mining Height ◽  
Strata Behavior ◽  
Mining Height

Exploiting the working face in coal mines using a super long mining length and large mining height has become important for intensive production with high yield and high efficiency. The paper develops a roof structure model to analyze the influence of 195 m, 242.4 m, and 376 m working face lengths at large mining height in Wangzhuang Coal Mine in China as the case study. The roof fracture characteristics, migration law, and strata behavior law under different working face lengths are compared and studied by numerical simulation, and the reliability of support selection in the working face at large mining height is analyzed by field measurement statistics. The results show that the roof fracture mode of a super large working face is a successive layered fracture. The length of the working face has little effect on the roof fracture step length, and the fracture step length is positively correlated with the thickness of the rock stratum. The roof subsidence law for a super large working face is different from the intermittent subsidence of the unimodal Gaussian distribution curve of ordinary working faces, which shows the intermittent subsidence of multiple ordinary working faces. The roof periodic weighting of a super large working face, which fluctuates violently within 100 m at both ends, is more drastic than that of an ordinary working face as a whole. Field statistical analysis shows it is more appropriate to choose high-strength support for a super large working face.

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