Research on deformation and failure laws of aquifuge of coal seam floor during pressurized working

2010 ◽  
pp. 259-264
Author(s):  
Zhaoning Gao ◽  
Xiangrui Meng ◽  
Xiangqian Wang
Keyword(s):  
Coal Seam ◽  
Deformation And Failure

Dynamic monitoring the deformation and failure of extra-thick coal seam floor in deep mining

2019 ◽  
Vol 163 ◽  
pp. 132-138 ◽  
Author(s):  
Wenlong Zhou ◽  
Pingsong Zhang ◽  
Rongxin Wu ◽  
Xiangyun Hu
Keyword(s):  
Coal Seam ◽  
Dynamic Monitoring ◽  
Thick Coal Seam ◽  
Deep Mining ◽  
Deformation And Failure

Deformation and Failure Features of Surrounding Rock for Combining Mining in Steep and Close Seam

2013 ◽  
Vol 327 ◽  
pp. 338-341 ◽  
Author(s):  
Jia Fan Zhang ◽  
Wei Gang Shi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Coal Seam ◽  
Difficult Problem ◽  
Surrounding Rock ◽  
Mining Method ◽  
Deformation And Failure ◽  
The World ◽  
Mining Methods ◽  
Different Thickness

Being closer space among steep and close seams, there always is a mutually destructive influence on adjacent seams while mining arbitrary coal seam within the same mining section, so the scientific mining method of steep and close seam is always the difficult problem to mining workers. Urumchi coalfield developed by Shenhua Xijiang corporation is a very few mine in China and even the world, in which entirely existing and exploiting steep and close seam. There are more than 30 layers of steep seams with different thickness and different distance. Aiming to the steep and close seams in Jiangou coalmine of urumchi mine, the combining mining methods with different mining approaches and different advancing distances were numerically simulated using 2-D and 3-D Finite Element Method, the deformation and failure features of surrounding rock were studied, and then the scientific of combining mine in steep and close seam was investigated.

Reasons and Control Countermeasures of Special Soft Coal Roadway Deformation in Liangbei Coal Mine

2013 ◽  
Vol 671-674 ◽  
pp. 1144-1149
Author(s):  
Le Tuan Cheng ◽  
Jia Lin Zhang ◽  
Zheng Sheng Zou ◽  
Qing Bo Li
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Mining Area ◽  
Gas Content ◽  
Deformation And Failure ◽  
Gas Outburst ◽  
Soft Coal ◽  
Coal Roadway ◽  
Roadway Stability ◽  
Roadway Deformation

B1 coal seam located at -550m level in Liangbei Coal Mine is a typical "three-soft" seam. The coal roadway with a depth of 610-750m lies under the critical softening depth of the roadway, and its support difficulty coefficient is 1.5-2.0. The coal has poor air permeability, high gas content and high gas pressure, so danger degree of the gas outburst is relatively strong. The coal seam was destroyed in a disastrous state by more than 100 boreholes for gas outburst prevention during the excavation. This results in the difficulty in the roadway support. Engineering geological characteristics of the coal roadway at 11 mining area are introduced. Based on the engineering geo-mechanics method, the reasons of deformation and failure of the coal roadway are analyzed. In view of problems in excavation and support, as well as the type of the coal roadway deformation mechanism, the borehole parameters are optimized for the gas outburst prevention, and bolt-net-cable coupling support with high convex steel-belt is used to control the coal roadway stability at 11 mining area. Practice shows that the effect is fine.

scholarly journals Analysis of Overlying Strata Movement and Disaster-Causing Effects of Coal Mining Face under the Action of Hard Thick Magmatic Rock

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 150 ◽  
Author(s):  
Quanlin Wu ◽  
Quansen Wu ◽  
Yanchao Xue ◽  
Peng Kong ◽  
Bin Gong
Keyword(s):  
Coal Seam ◽  
Fracture Zone ◽  
Magmatic Rock ◽  
Ratio Test ◽  
Large Area ◽  
Deformation And Failure ◽  
Key Strata ◽  
Magmatic Rocks ◽  
Working Face ◽  
Bed Separation

When the hard and thick key strata are located above the working face, the bed separation structure is easy to be formed after mining because of the high strength and integrity of the hard and thick key strata and the initial breaking step is large. After the hard, thick strata are broken, the overburden will be largely collapsed and unstable in a large area and the dynamic disaster is easily induced. In this study, considering the fundamental deformation and failure effect of coal seam, the development law of the bed separation and the fractures under hard and thick magmatic rocks and the mechanism of breaking induced disaster of hard and thick magmatic rocks are studied by similar simulation tests. The results of the study are as follows: (1) The similar material ratio of coal seam is obtained by low-strength orthogonal ratio test of similar materials of coal seam, that is, cement:sand:water:activated carbon:coal = 6:6:7:1.1:79.9. (2) The magmatic rocks play a role in shielding the development of the bed separation, which makes the bed separation beneath the magmatic rock in an unclosed state for a long time, providing space for the accumulation of gas and water. (3) The distribution pattern of the fracture zone shows different shapes as the advancing of working face and the fracture zone width of the rear of working face coal wall is larger than that of the front of the open-off. (4) The breaking of magmatic rocks will press the gas and water accumulated in the bed separation space below to rush towards the working face along the fracture zone at both ends of the goaf. The above results are verified through the drainage borehole gas jet accident in the Yangliu coal mine. The research results are of great significance for revealing the occurrence process of dynamic disasters and adopting scientific and reasonable preventive measures.

scholarly journals Reconstruction of 3D Micro Pore Structure of Coal and Simulation of Its Mechanical Properties

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Guang-zhe Deng ◽  
Rui Zheng
Keyword(s):  
Rock Mass ◽  
Stress Distribution ◽  
Coal Seam ◽  
Pore Structure ◽  
Three Dimensional ◽  
Low Permeability ◽  
Deformation And Failure ◽  
Coal Rock ◽  
Shear Failures ◽  
Negative Exponential

This article takes the low permeability coal seam in the coalfield of South Judger Basin in Xinjiang, as a research object. The pore structure characteristics of coal rock mass in low permeability coal seam were analyzed quantitatively using scanning electron microscopy (SEM) through the methods of statistics and digital image analysis. Based on the pore structure parameters and the distribution function of the coal rock mass, a three-dimensional porous cylinder model with different porosity was reconstructed by FLAC3D. The numerical simulation study of reconstructed pore model shows that (1) the porosity and the compressive strength have obvious nonlinear relation and satisfy the negative exponential relation; (2) the porosity significantly affects the stress distribution; with the increase of micro porosity, the stress distribution becomes nonuniform; (3) the compressive failures of different models are mainly shear failures, and the shape of fracture section is related to porosity; (4) the variation of seepage coefficient of the pore reconstruction model is consistent with the development of micro cracks. The micro mechanism of the deformation and failure of coal and the interaction of multiphase flow with porosity are revealed, which provides a theoretical reference for the clean development of the low permeability coal seam.

The characteristics of deformation and failure of coal seam floor due to mining in Xinmi coal field in China

2014 ◽  
Vol 73 (4) ◽  
pp. 1151-1163 ◽  
Author(s):  
Shuyun Zhu ◽  
Zhenquan Jiang ◽  
Kaijun Zhou ◽  
Guangqing Peng ◽  
Chaowei Yang
Keyword(s):  
Coal Seam ◽  
Coal Field ◽  
Deformation And Failure

scholarly journals Study on Deformation and Failure Characteristics of Weak Cemented Roof in Shallow and Extra Thick Coal Seam Mining

2021 ◽  
Author(s):  
Chang Liu ◽  
Pingsong Zhang ◽  
Duoxi Yao ◽  
Yuancaho Ou ◽  
Yutong Tian
Keyword(s):  
Coal Seam ◽  
Apparent Resistivity ◽  
Maximum Height ◽  
Geoelectric Field ◽  
Electrical Method ◽  
Deformation And Failure ◽  
Fractured Zone ◽  
Working Face ◽  
Seam Mining ◽  
Loose Layer

Abstract Detecting the development height of water flowing fractured zone in the roof of coal seam is of great significance for the roof safety of working face with developed sandstone and thick loose layer. This paper analyzes the influence of the induced polarization effect of electrode on the traditional single-mode parallel electrical method. In order to avoid this interference, the dual-mode parallel electrical method is applied to monitor the roof deformation and failure of a coal mine in Ordos Basin. The monitoring results show that: under the influence of mining, the change of geoelectric field of coal seam roof is dynamic, the apparent resistivity of initial mining fracture is high, the apparent resistivity of surrounding rock water filling mining fracture is low, and the apparent resistivity of fracture water flowing to goaf is high again. According to the characteristics of geoelectric field, the maximum height of water flowing fracture zone is 122 M; The average mining coal thickness of the working face is 11 m, and the fracture / mining thickness ratio is 11.1. The results of plastic zone show that the maximum height of water flowing fractured zone above the working face is 122 m, which is consistent with the test results. The vertical stress response characteristics of roof monitoring points are zonal. Under the influence of mining, the loose layer near the surface above the working face is cracked. The edge type ground fissures exist for a long time, and there are a series of geological problems such as soil erosion, ground subsidence.

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