scholarly journals RESULTS OF MINE SURVEYING AND GEODESIC OBSERVATIONS ON DEFORMATIONS OF APSAT COAL CUTTING BOARDS

2020 ◽  
Vol 1 (1) ◽  
pp. 186-193
Author(s):  
Vladimir P. Stupin ◽  
Evgenii N. Beliaev ◽  
Irina A. Karpova

The methodology and organization of surveying and geodesic monitoring of the sides of a coal mine using laser scanning are described. The results of observations are presented. Conclusions about the stability of the sides of the coal mine are made and the possibilities of the methods used are evaluated.

2018 ◽  
Vol 92 (6) ◽  
pp. 732-742 ◽  
Author(s):  
Arka Jyoti Das ◽  
Prabhat Kumar Mandal ◽  
Satya Prakash Sahu ◽  
Angad Kushwaha ◽  
Rana Bhattacharjee ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jucai Chang ◽  
Kai He ◽  
Zhiqiang Yin ◽  
Wanfeng Li ◽  
Shihui Li ◽  
...  

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jianning Liu ◽  
Manchao He ◽  
Yajun Wang ◽  
Ruifeng Huang ◽  
Jun Yang ◽  
...  

The key block of the basic roof is the main contributor to the structural stability of a roadway. Research on the stability of the key block structure is of great significance for the promotion of noncoal pillar mining with automatically formed gob-side entry (GEFANM) technology. This paper is set in the engineering context of the GEFANM experiment at the Ningtiaota Coal Mine. The study fully considered the differences in the gob roof caving on the roof-cutting-line side, and the range of rotation angles to maintain a stable key block was determined. Based on this range of rotation angles, the range of safe bulking coefficients of gangue was calculated. The bulking coefficient of the gangue on the gravel side of the roadway was used as the metric in a new monitoring method and in the calculation of the field parameters. The range of safe bulking coefficients was determined to be 1.40–1.37. Field monitoring was conducted to obtain the gangue bulking coefficient on the gravel side. Combining the roof and floor convergence data, when the bulking coefficient fell within the safe range, the convergence was 95–113 mm. In this stage, the key block structure was stable. When the gangue bulking coefficient fell outside the safe range, the convergence was larger, and cracks were observed. The key block may be vulnerable to instability. The results affirmed that the gangue bulking coefficient can be used as a monitoring metric to study the stability of key block structures.


2011 ◽  
Vol 361-363 ◽  
pp. 183-187
Author(s):  
Xiao Ren Mei

Heidaigou Surface Coal Mine (HSCM) is a large surfaces coal mine that first uses the throwing blasting - dragline stripping technology. Lots of new demanding prompt solution issues appears in HSCM without any successful experience in China, such as the stability of dragline stripping bench, the design and implementation of throwing blasting parameters, and the optimization of dragline stripping technology parameters. Rigid Body Limit Equilibrium Method (RBLEM) was used to study the safety and stability of dragline solid high bench and dragline stripping loosen bench under different workface parameters and influence factors. The safe operation parameters of dragline stripping bench are proposed. The dozer lowered height of the stripping bench, the width of extended bench and dragline operation parameters are optimized using the Optimization System of Dragline Stripping Technology (OSDST). The results can provide the decision support for HSCM.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Mingze Du ◽  
Yanchun Xu ◽  
Heng Duan ◽  
Wen Li

The hydrophobicity of the aquifer at the bottom of the porous alluvium will affect the stability of the shaft. According to the changes of water level and the compressive amount of alluvium, we can evaluate the shaft stability and predict the shaft failure. In this work, the simulation model of the auxiliary shaft in the Zhuxianzhuang Coal Mine is generated by using the Nsdc software to evaluate the stability of the shaft during drastic drawdown dewatering. Based on the measured hydrophobic compression ratio in an adjacent coal mine, the compressive amounts of the strata near the main and auxiliary shafts in the Zhuxianzhuang Coal Mine are predicted under the condition of drastic drawdown dewatering, which will be 249.69 mm and 302.75 mm, respectively. It is more likely that the shaft wall may fracture in the 15th day (fourth load level) under the condition of drastic drawdown dewatering. The formation compressive amount near the auxiliary shaft is approximately 320 mm, which is close to the measured predicted value. At the same time, the Fisher discriminant model is established, and it is predicted that the state of the main and auxiliary shafts will be failure under the conditions of drastic drawdown dewatering in the Zhuxianzhuang Coal Mine. Based on the simulating results, the technical means of using the ground grouting for early prevention and control is proposed.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 628 ◽  
Author(s):  
Junwen Zhang

Split-level longwall gob-side entry (SLGE) has been applied as a special form of small gate pillar mining (or non-coal pillar mining) in thick coal seams. The stability of the coal pillar directly affects the rationality of the layout of the SLGE. Starting from the mining-induced influence around the SLGE, this paper compares the mechanical properties of coal under different mining effects, and studies the rationality of “zero pillar” location against the Xiegou coal mine. The study shows that the key to success of the application of the SLGE is the existence of an intact zone within the triangular coal pillar in spite of double disturbances due to tunneling and coal mining extraction. Laboratory testing shows that the density and uniaxial compressive strength of rock specimens obtained from the triangular coal pillar are smaller than that from the other part of the panel which is concluded to be due to the varied degree of mining-induced influence. The numerical modeling results show that most of the triangular coal pillar is intact after extraction of the panel, and that the peak stress is located in the solid coal beyond the triangular coal pillar. The plastic zone of the triangular coal pillar is only about 1 m after the excavation of the tail gate of the next split-level panel. The physical modeling shows that the tail gate of the next panel is in the destressed zone with only a very small stress fluctuation during the extraction of the next panel. The study shows that the location of the SLGE at Xiegou coal mine is reasonable. SLGE is preferable for ultra-thick coal seams.


2013 ◽  
Vol 353-356 ◽  
pp. 751-755 ◽  
Author(s):  
Yong Cheng Yan ◽  
Xian Zhang Ling ◽  
Feng Zhang ◽  
Jia Hui Wang

Taking section W400 of Fushun west open-pit coal mine for the research, the interface model of fracture zone and surrounding rock was established. FLAC3D is used to analysis the influence of excavation and backfill of open-fit coal mine to the slope stability and deformation. The numerical results and analysis show that: (1) when the open-pit coal mine slope is excavated to final production line, the safety coefficient is 2.98, with the excavation, the deformation of the Fushun No.1 Refinery Factory area increases. (2) With the increase of backfilling, the slope coefficient increases to 3.32, this will reduce the deformation of the Fushun No.1 Refinery Factory area. Furthermore, the positions of the dangerous slip surface and serious deformation part of factory area should be regards as key areas. These conclusions could provide technical basis for the stability analysis of Fushun west open-pit coal mine.


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