Developing coal pillar stability chart using logistic regression

2013 ◽  
Vol 58 ◽  
pp. 55-60 ◽  
Author(s):  
R.K. Wattimena ◽  
S. Kramadibrata ◽  
I.D. Sidi ◽  
M.A. Azizi
Keyword(s):  
Logistic Regression ◽  
Coal Pillar ◽  
Pillar Stability ◽  
Stability Chart

scholarly journals The Influence of the Backfilling Roadway Driving Sequence on the Rockburst Risk of a Coal Pillar Based on an Energy Density Criterion

2018 ◽  
Vol 10 (8) ◽  
pp. 2609 ◽  
Author(s):  
Yi Xue ◽  
Zhengzheng Cao ◽  
Feng Du ◽  
Lin Zhu
Keyword(s):  
Energy Density ◽  
Dynamic Instability ◽  
Coal Pillar ◽  
Optimal Choice ◽  
Mining Technology ◽  
Pillar Stability ◽  
Rockburst Hazard ◽  
Density Factor ◽  
Coal Pillars ◽  
Energy Density Factor

The rockburst hazard has always been an important issue affecting the safety production of coal mines in China. The unreasonable sequencing of roadway driving can lead to the dynamic instability of coal pillars, which subsequently causes rockburst accidents in roadway backfilling mining engineering and poses a serious threat to the safety of the mines. Roadway backfilling mining technology is an effective approach with which to mine corner residual coal resources under buildings, railways, and rivers. An energy density criterion is established and programmed with FISH language using numerical analysis software for the rockburst risk evaluation of coal pillars. On this basis, a numerical simulation model is established based on four scheme types, namely, the sequential mining, one-roadway interval mining, two-roadway interval mining, and three-roadway interval mining schemes. The influence of the backfilling roadway driving sequence on coal pillar stability is investigated, and the change law of vertical stress and energy density factor of coal pillars in different driving sequences in roadway backfilling mining technology are analyzed. According to the research results, the maximum energy density factor value of 21,172 J/m4 for coal pillars in one-roadway interval mining is the lowest among the different schemes. Therefore, the one-roadway interval mining scheme is the optimal choice in roadway backfilling mining technology. The results can be treated as an important basis for the prevention and treatment of coal pillar instability and rockburst in roadway backfilling mining technology.

scholarly journals Improvement of the Loading Capacity of Narrow Coal Pillars and Control Roadway Deformation in the Longwall Mining System. A Case Study at Khe Cham Coal Mine (Vietnam)

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Le QUANG PHUC ◽  
V. P. ZUBOV ◽  
Phung MANH DAC
Keyword(s):  
Longwall Mining ◽  
Coal Pillar ◽  
Rock Bolt ◽  
Mining System ◽  
Pillar Stability ◽  
Roadway Support ◽  
Coal Pillars ◽  
The Stability ◽  
Safe Condition ◽  
Cable Bolt

Currently, the application of coal pillars to protect an adjacent roadway is a common method in Vietnam when exploiting according to the longwall system. Therefore, the width of a coal pillar is an important issue for the stability of a roadway. In order to reduce coal loss in these coal pillars, they tend to be designed in a narrow coal pillar style but still have to ensure that the adjacent roadway can meet safe coal production conditions. The stability of roadways and coal pillars is related to many factors such as technical mechanical characteristics, physical and mechanical properties of coal, stress environment and support methods. The bearing structure of the coal pillar and the around rock a roadway is analyzed and it has been shown that enhancing roadway support and improving the carrying capacity of coal pillars can control the deformation of the surrounding rock. A study related to the stability and safety of roadways and small coal pillars in the longwall mining system has been carried out. Stabilization factors have been considered, especially the state of stress in the coal pillars and the deformation of the roadway. By applying the numerical simulation method, the stress of the coal pillar and the deformation of the adjacent roadway under different supporting solutions were analyzed and evaluated. By using this method, the rock bolt roadway support solution combined with the long cable bolt in the roadway roof and the coal pillar was selected in the safe condition of the mining process. Because cable bolt can improve the flexibility of the coal pillar such as: reducing the size of the plastic area on both sides of the pillar; enhancing coal pillar stability in the core area by providing great drag and tensile for coal pillars; contributing to improving the anchor point fixation of rock bolt. The conclusions obtained may provide a certain reference parameters to improve mining efficiency and labor safety in underground coal mines.

Research on evaluation and control technology of coal pillar stability based on the fracture digitization method

Measurement ◽  
2020 ◽  
Vol 158 ◽  
pp. 107713 ◽  
Author(s):  
Sifei Liu ◽  
Zhijun Wan ◽  
Yuan Zhang ◽  
Shuaifeng Lu ◽  
Xvpeng Ta ◽  
...  
Keyword(s):  
Coal Pillar ◽  
Control Technology ◽  
Pillar Stability ◽  
Research On Evaluation ◽  
And Control

Elastic-Plastic Mechanics Analysis on Stability of Coal Pillar

2008 ◽  
Vol 33-37 ◽  
pp. 1123-1128 ◽  
Author(s):  
Wei Gao
Keyword(s):  
Coal Seam ◽  
Coal Pillar ◽  
New Method ◽  
Engineering Practice ◽  
Strip Mining ◽  
Mining Engineering ◽  
Pillar Stability ◽  
Elastic Plastic ◽  
Equilibrium Method ◽  
Mechanics Analysis

Because it is very important to study the coal pillar stability, a lot of methods to do this have been proposed. But most of those methods do not consider the nature of coal material and only study the coal pillar that is level. To solve this problem suitably, here a new method is proposed. In this method, the plastic softening nature of coal material is considered. And also, the coal seam pitch is considered in our analysis. Based on real deformation of coal pillar and the previous study, the limiting equilibrium method is applied. At last, the rationality of our method is verified through a strip mining engineering example. And the results show that, the computing results of our method are coincided with measuring results very well and our method can be applied in real engineering practice very well.

Modeling and Numerical Optimal Simulation of Coal Pillar’s Failure Process on Longwall Leaving Coal Pillar Mining

2011 ◽  
Vol 88-89 ◽  
pp. 285-290 ◽  
Author(s):  
Xiao Ping Shao ◽  
Yu Cheng Xia
Keyword(s):  
Optimization Design ◽  
Design Research ◽  
Failure Process ◽  
Coal Pillar ◽  
Shaanxi Province ◽  
Mining Method ◽  
Pillar Stability ◽  
Plastic Failure ◽  
Mining Methods ◽  
Coal Pillars

To further optimize mining methods and parameters at regions of “protecting water mining”, this paper has made modeling and numerical optimal simulation of coal pillar’s failure process under two kinds of mining method including “taking 8 remaining 7” leaving the region pillars and “taking 12 remaining 8” leaving strip coal pillars for Yubojie coal mine in northern Shaanxi province in China. Simulation showed that the stability of strip coal pillars is better than the region coal pillars at the same advancing distance. The region coal pillars first appeared corner plastic failure and maybe become hexagonal pillars. Plastic failure of the rectangular pillar extended and penetrated from the corner along the edge. Plastic damage of pillars showed tendency from the middle to the roadway side of the face along the length direction of face. Stability of central elastic core of coal pillar is the basis of pillar stability. Simulation results showed that it is feasible to optimize mining methods and parameters of “protecting water mining" areas based on modeling and numerical simulation of pillar failure process. The method has provided a useful reference to mining method and optimization design research for other regions with same type of domestic and international coal mines.

scholarly journals Effect of mining parameters on surface deformation and coal pillar stability under customized shortwall mining of deep extra-thick coal seams

2021 ◽  
Vol 7 ◽  
pp. 2138-2154
Author(s):  
Shuyin Jiang ◽  
Gangwei Fan ◽  
Qizhen Li ◽  
Shizhong Zhang ◽  
Liang Chen
Keyword(s):  
Surface Deformation ◽  
Coal Pillar ◽  
Coal Seams ◽  
Pillar Stability

Research on the Design for Strip-Partial Mining Method under Villages at Xiaotun Colliery

2011 ◽  
Vol 361-363 ◽  
pp. 217-221 ◽  
Author(s):  
Rui Min Feng ◽  
Jin Long Zhang ◽  
Hui Fu ◽  
Lei Pei
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Coal Pillar ◽  
Field Measurements ◽  
Mining Method ◽  
Pillar Stability ◽  
Surface Movement ◽  
Mining Condition ◽  
Movement And Deformation ◽  
Mining Scheme

Basing on the geological mining condition under villages at Xiaotun Mine, according to the existing theories of the strip-partial mining, using the method of analyzing the field measurements date and calculating by empirical formula, the safe range of mining and retained widths can be confirmed, the mining schemes for different widths of coal pillar can be designed, and the optimum scheme can be worked out; and then the coal pillar stability of each mining scheme will be calculated through numerical simulation analysis, providing the basis for appropriately selecting the optimum scheme; on this basis, through simulation prediction of the surface movement and deformation, the surface movement and deformation laws of strip-partial mining is revealed to guide production of Xiaotun colliery.

scholarly journals Study on Intelligent Identification Method of Coal Pillar Stability in Fully Mechanized Caving Face of Thick Coal Seam

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 305 ◽  
Author(s):  
Jingjing Dai ◽  
Pengfei Shan ◽  
Qi Zhou
Keyword(s):  
Coal Seam ◽  
Simulation Experiment ◽  
Coal Pillar ◽  
Shanxi Province ◽  
Parameter Determination ◽  
Pillar Stability ◽  
Thick Coal Seam ◽  
Identification Method ◽  
Optimal Value ◽  
The Relationship

The combination of coal precise mining and information technology in the new century is one of the important directions for the future development of coal mining. Taking the fully mechanized top coal caving condition of a thick coal seam in the 90,101 working face of Baoshan Yujing Coal Mine in Shanyin City, Shanxi Province as an example, the intelligent identification method of section coal pillar stability was studied. The load transfer law of overlying strata in the upper part of coal pillar was analyzed, and the coal pillar values of each index were obtained by using an empirical formula, mean impact value-genetic algorithm-BP neural network (MIV-GA-BP) simulation experiment, and finite difference algorithm. The Delphi index evaluation system was used to calculate the optimal value of the coal pillar. The results showed that the non-contact cantilevered triangle on the two wings of the coal pillar in the goaf reduced the stress on the coal pillar; according to the width of the coal pillar at 10 m, 14 m, 16 m, and 20 m, combined with the relationship between the plastic zone and the core zone of coal pillar, and the relationship between the stress field and the ultimate strength of coal pillar, the numerical simulation value of the coal pillar was determined. The MIV (mean impact value) characteristics screened out the influencing factors of coal pillar width in the section near the horizontal fully mechanized top coal caving face order of importance; the relative error between the predicted value and the expected value of the MIV-GA-BP simulation experiment was less than 5%, which has good stability for the multi-factor nonlinear coupling prediction problem; and the optimal value of the coal pillar was 16.03 m by the intelligent identification method of the coal pillar. When the 16 m pillar was used, the surrounding rock deformation of the roadway was small, and the control effect was good. The research results provide a theoretical basis and reference for the parameter determination of similar projects.

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