scholarly journals Experimental Study on Impermeability Law of Aquiclude Reconstructed by Mudstone of External Dump in Arid Zone

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Li Ma ◽  
Chendong Liu ◽  
Yinli Bi ◽  
Suping Peng ◽  
Kaisheng Jiang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Particle Size ◽  
Coal Mine ◽  
Physical Simulation ◽  
Arid Zone ◽  
Soil Column ◽  
Infiltration Rate ◽  
Quadratic Functions ◽  
Open Pit ◽  
Drop Rate

In order to achieve the goal of ecological restoration, plant irrigation, and water retention in the external dump of open-pit coal mine in the arid desert area, it is proposed to use the mudstone in the stripped material to reconstruct the surface aquiclude and improve the water holding capacity of the topsoil. By taking the Hongshaquan Open-Pit Coal Mine as the study object, the red mudstone of mining level +650 was selected as the topsoil aquiclude material through the geological survey. XRD diffraction experiments are used to determine the composition of red mudstone including kaolinite mineral, quartz, potash feldspar, albite, and illite. The moisture content of the red mudstone is 4.16% as measured by the indoor drying experiment. And the particle size of 0.5 mm, 1 mm, and 2 mm and the thickness of 5 cm, 10 cm, and 20 cm rock samples were selected to conduct the indoor soil column experiment. Three indicators of initial infiltration rate, stable infiltration rate, and average infiltration rate were obtained according to the analysis and calculation of the water column drop rate, wet peak drop rate, and cumulative infiltration rate so that the permeability law and coefficient of each group of tests can be known. The finite element transient analysis theory and numerical simulation method were adopted to verify the results of physical experiments. The research results show that +650 level red mudstone has a strong antiseepage ability, and the smaller the particle size, the better the antiseepage performance. For 0.5 mm and 2 mm particle sizes, as the paving height increases, the water-proof effect is better. The laying height of 1 mm particle size has no obvious influence on the water barrier effect. The physical simulation was confirmed to have the same result trend as the numerical simulation, both of which are quadratic functions with the error within a reasonable range.

Zonal extraction technology and numerical simulation analysis in open pit coal mine

2012 ◽  
Vol 22 (4) ◽  
pp. 487-491 ◽  
Author(s):  
Yanlong Chen ◽  
Qingxiang Cai ◽  
Tao Shang ◽  
Hongge Peng ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Simulation Analysis ◽  
Open Pit ◽  
Extraction Technology

Based on the Visual Modflow Surge Water Numerical Simulation Study

2012 ◽  
Vol 542-543 ◽  
pp. 1384-1389
Author(s):  
Li Wang ◽  
Ye Liu
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Permeability Coefficient ◽  
Open Pit ◽  
Mining District ◽  
Visual Modflow ◽  
Mining Areas ◽  
Drainage Patterns ◽  
Multiple Regression Method ◽  
Numerical Calculation Method

The detailed analysis in shengli coalfield, two East open-pit coal mine geological ， hydro-geological characteristics and groundwater recharge, Runoff, drainage patterns. And on the analysis results of this analysis are mining areas of conceptual models of hydrogeology, numerical calculation method based on Visual Modflow first mining district 4 coal mine water water-bearing rock group. This article by multiple regression method using logging parameter estimation of permeability coefficient, solved in numerical simulation used in hydrological study on permeability coefficient of hole to determine does not meet the need of traditional issues.

Numerical Simulation of Slope Stability in the First Mining of Open-Pit Coal Mine

2013 ◽  
Vol 807-809 ◽  
pp. 2371-2377
Author(s):  
Guang Yi Sun ◽  
Xiao Luo
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Slope Stability ◽  
Coal Mine ◽  
Paper Analysis ◽  
Open Pit ◽  
Stress And Strain ◽  
Safety Coefficient ◽  
Mine Slope ◽  
Mining Slope

This paper analysis open-pit coal mine slope stability in the first mining with FLAC3D, reveal the mechanism of slope deformation, through analysis the stress and strain nephogram of model ZK8 of the first mining slope, and calculation safety stability coefficient, finally concluding stope slope of the first mining occur slip as circular form under their own gravity. The safety factor of model ZK8 is more than stope slope safety coefficient 1.20, slope is in steady state, obtained the accurate and reliable analysis results of stability.

scholarly journals Study on the Pressure-Bearing Law of Backfilling Material Based on Three-Stage Strip Backfilling Mining

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 211 ◽  
Author(s):  
Xiaoping Shao ◽  
Xin Li ◽  
Long Wang ◽  
Zhiyu Fang ◽  
Bingchao Zhao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thin Plate ◽  
Coal Mine ◽  
Physical Simulation ◽  
Plate Theory ◽  
Coal Pillar ◽  
Smooth Transition ◽  
Main Bearing ◽  
Working Face ◽  
Rock Load

During strip backfilling mining in coal mines, the backfilling material is the main support structure. Therefore, studying the pressure law of the backfilling material is essential for the safe and efficient mining of coal resources. Based on research into strip backfilling mining at working face number 3216 of the Shanghe Coal Mine, and to smooth transition of overlying strata loads to the backfilling material, this study proposes a three-stage strip backfilling mining method. Based on thin-plate theory, an elastic thin-plate model, a reasonable spacing of strip mining is constructed, and the reasonable mining parameters of “mining 7 m to retain 8 m” at working face number 3216 of the Shanghe Coal Mine are determined. The law of backfilling pressure in three-stage strip backfilling mining is studied through numerical simulation and physical simulation experiments. The results show that field measurement results are basically consistent with the experimental results and numerical simulation results. When three-stage strip backfilling mining is adopted, the stage-one backfilling material is the main bearing body to which the overlying rock load transfers smoothly and gradually, and the structure of the “overburden-coal pillar (or backfilling strip)” in the stope remains stable. In three-stage strip backfilling mining, the overlying rock load is ultimately transferred to the stage-one backfilling material, the stage-two backfilling material is the auxiliary bearing body, and the stage-three backfilling material mainly provides long-term stable lateral support for the stage-one backfilling material.

scholarly journals Effect of Coalbed Methane Well Fracturing on Slope Stability of Open-Pit Coal Mine: A Case Study of Shengli East No. 2 Open-Pit Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Qingzhong Zhu ◽  
Bo Wang ◽  
Xin Zhao ◽  
Chunchun Liu ◽  
Qing Yu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Slope Stability ◽  
Coal Mining ◽  
Dynamic Fracture ◽  
Coal Mine ◽  
Coalbed Methane ◽  
Limit Equilibrium ◽  
Open Pit ◽  
Fracture Width ◽  
Fracture Height

The impact of hydraulic fracture from CBM well fracturing on slope stability of the Shengli East No. 2 open-pit coal mine is analyzed by numerical simulation and limit equilibrium methods. The interference effect of coalbed methane (CBM) well fracturing on slope stability of the open-pit coal mine promotes the coordinated development of CBM, and open-pit coal is discussed before and after coal mining. It shows that nearly horizontal fractures are formed in the coal seam due to CBM well fracturing, of which the dynamic facture length and propping fracture length are 137.2 m and 105.2 m, respectively. Moreover, the dynamic fracture height is 137.2 m and propping fracture height is 130.6 m. At the location of perforation, the dynamic fracture width is 0.873 cm and average propping fracture width is 0.111 cm. The CBM well fracturing barely imposed any effect on slope stability before open-pit coal mining. The maximum vertical displacement at the toe of slope induced by fracturing is 0.293 mm. In situations with and without CBM well fracturing, vertical stress distributions in the toe, top, and interior of slope have no obvious difference. There is some extent of vertical stress increase within the interior of slope, which is merely 0.2 MPa higher than that in the condition of initial in situ stress equilibrium. The presence of hydraulic fractures has little effect on the overall displacement of slope during coal mining; and there is no obvious difference between the slope stability during coal mining and the slope stability impacted by fracturing. According to the results of limit equilibrium method and numerical simulation, the overall slope stability coefficient is 1.5–1.97, which accords with the requirements of the Design Code for Open-Pit Mine of Coal Industry (GB50197-2015). Therefore, more attentions should be paid to the ways of excavation and sloping during coal mining, avoiding slope instability caused by excavation.

Effect Analysis of Nitrogen Injection on the Variation of “Oxidation Zone” in Coal Mine Gob Based on Numerical Simulation

2016 ◽  
Vol 9 (1) ◽  
pp. 47-54
Author(s):  
Jing Shen ◽  
Mingran Chang
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Heat Dissipation ◽  
Spontaneous Combustion ◽  
Oxidation Zone ◽  
Effect Analysis ◽  
Mine Fire ◽  
Nitrogen Injection ◽  
The Difference ◽  
Residual Coal

One of the main reasons for coal mine fire is spontaneous combustion of residual coal in gob. As the difference of compaction degree of coal and rock, the underground gob can be considered as a porous medium and divided into “three zones” in accordance with the criteria. The “three zones” are “heat dissipation zone”, “oxidation zone” and “choking zone”, respectively. Temperature programming experiments are taken and numerical simulation with obtained experimental data is utilized to analyze the distribution of “three zones” in this paper. Different width and depth of “oxidation zone” are obtained when the inlet air velocity is changed. As the nitrogen injection has inhibition effect on spontaneous combustion of residual coal in gob, nitrogen is injected into the gob. The widths of “oxidation zone” are compared before and after nitrogen injection. And ultimately the optimum location and volume of nitrogen injection are found out.

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