scholarly journals Height of Water-Conducting Fractured Zone with Coal Mining in Loess Covered Area

2021 ◽  
Vol 861 (5) ◽  
pp. 052055
Author(s):  
Tao Li ◽  
Ying Gao ◽  
Siyou Xiao ◽  
Junwei Yang ◽  
Aoran Mei
Keyword(s):  
Coal Mining ◽  
Fractured Zone ◽  
Covered Area

scholarly journals Height of the Fractured Zone in Coal Mining under Extra-Thick Coal Seam Geological Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Dequan Sun ◽  
Xiaoyan Li ◽  
Zhijie Zhu ◽  
Yang Li ◽  
Fang Cui
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Process Analysis ◽  
Failure Process ◽  
Analysis Method ◽  
Coal Seams ◽  
Fractured Zone ◽  
Seam Mining ◽  
Borehole Televiewer ◽  
Overlying Strata

The height of the fractured zone caused by coal mining is extremely significant for safely mining under water, water conservation, and gas treatment. At present, the common prediction methods of overburden fractured zone height are only applicable to thin and medium-thick coal seams, not suitable for thick and extra-thick coal seams. In order to determine the overburden fractured zone distribution characteristics of extra-thick seam mining, failure process analysis method of overlying strata was proposed based on key strata theory. This method was applied to 15 m coal seam of Tongxin coal mine, and fractured zone height was determined to be 174 m for 8100 panel. EH4 electromagnetic image system and borehole televiewer survey were also conducted to verify the theory results. The distribution of the electrical conductivity showed that the failure height was 150–170 m. Observation through the borehole televiewer showed that the fractured zone height was 171 m. The results of the two field test methods showed that the fractured zone height was 150–171 m, and it was consistent with the theory calculation results. Therefore, this failure process analysis method of overlying strata can be safely used for other coal mines.

Predicting the height of water-flow fractured zone during coal mining under the Xiaolangdi Reservoir

2010 ◽  
Vol 20 (3) ◽  
pp. 434-438 ◽  
Author(s):  
Zhimin XU ◽  
Yajun SUN ◽  
Qinghong DONG ◽  
Guowei ZHANG ◽  
Shi LI
Keyword(s):  
Coal Mining ◽  
Water Flow ◽  
Fractured Zone ◽  
Xiaolangdi Reservoir

Prediction of Groundwater Inrush into Coal Mines from Aquifers Overlying the First Coal Seam in Eastern Ningxia Coalfield, China

2014 ◽  
Vol 1073-1076 ◽  
pp. 1634-1640
Author(s):  
En Ke Hou ◽  
Jie Feng ◽  
Fan Yang ◽  
Yan Jing Zhang
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Water Flow ◽  
Mining Area ◽  
Observation Data ◽  
Groundwater Inrush ◽  
Fractured Zone ◽  
Mining Areas ◽  
Seam Mining ◽  
Runoff Discharge

In the region where Eastern Ningxia coalfield locates, with the fragile eco-environment and the relative short water resources, it is significant to make clear the influence of coal mining on the groundwater in this region. According to analyses of water-filling factors for the 21 mine fields in the 7 mining areas and 1 independent mine field of Eastern Ningxia coalfield. Firstly, this paper selects the formula in the regulations on the preserving of the coal pillar and coal mining under buildings, water, rail and main shafts (regulations for short) and the Standard on the Exploration of Hydrogeology and Engineering-Geology in the Mining Area (GB12719-91) (standard for short) to calculate the height of water-flow fractured zone in the first coal seam mining, and compares the analysis results of the above formula to the observation data of 3 working faces, and determine the estimated method on the height of water-flow fractured zone, and then use “three maps-two predictions” method to complete the criterion of aquifer water-enrichment and inbreak in safety of the first coal seam. Finally, analyzing the influence of coal mining on the direction of groundwater and recharge-runoff-discharge conditions, the final comprehensive division program on the risk of the groundwater inrush is presented. The research results served as the general guidelines for the mine operations.

Research on the Influence of Coal Mining on Aquifer

2015 ◽  
Vol 730 ◽  
pp. 113-116
Author(s):  
Peng Jie Wang ◽  
Hua Jin ◽  
Tian Ju Zhang
Keyword(s):  
Surface Water ◽  
Coal Mining ◽  
Water Inrush ◽  
Water Environment ◽  
Influence Factors ◽  
Shanxi Province ◽  
Coal Seams ◽  
Fractured Zone ◽  
Aquifer Systems ◽  
The Impact

The height of the water flowing fractured zone and the extent of water inrush caused by coal mining are the main influence factors on aquifer systems. Taking a coal mine of Shanxi province as research object, the impact of coal mining on regional surface water and groundwater was evaluated. The heights of the water flowing fractured zone of coal seams in No.3, No.8-2, No.15-1 and No.15-3 were 68.62~98.62m, 31.21~58.25m, 30.59~33.41m and 31.45~42.33m respectively. The results showed that the surface would not be penetrated and the surface water environment could not be impacted seriously. While the lower shihezi formation aquifer which was the mined-out area of coal seams in No.3 and No.8-2 would be penetrated. Coal seam in No.15-3 belongs to relatively safe area, which water inrush coefficient ranged from 0MPa/m to 0.0148MPa/m.

A Case Study on Development of Water-flow Fractured Zone During Close-Distance Repeated Coal Mining

2021 ◽  
Author(s):  
Yuanzhong Luan ◽  
Yaofan Shi ◽  
Shui Yu ◽  
Yue Dong ◽  
Yong Yan
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Water Flow ◽  
Water Injection ◽  
Scientific Basis ◽  
Hole Drilling ◽  
Fractured Zone ◽  
Working Face ◽  
Distance Working ◽  
Close Distance

Abstract The upper and lower seam of seam No.3 of some coal mines in Shandong Province are in close proximity which can be regards as close-distance coal seam mining.This paper takes the close-distance working face of Fucun coal mine as engineering background and mainly focuses on the investigation and research on inaccuracy of the forecasting and incompetence of the developing principles of water-flow fractured zone(WFFZ)during close-distance coal seam group mining.First,calculations on the height of WEEZ by adopting empirical formula.And FLAC3D software was established to calculate the height of the overburden WFFZ after repeated mining of the upper and lower seam of seam No.3.At the same time,using the double-ended water plugging observation technology of downhole drilling and upward hole drilling by analyzing the water injection loss ratio of the reference hole and the post-mining hole,the accurate numerical values of the WFFZ and the ratio of WFFZ height to mining height(W-M ratio)are obtained.The comparative analysis shows that the numerical simulation results are close to the measured ones,and the empirical formula is not applicable to the near-distance repeated mining.Finally,the prediction model is established based on the measured height of the WFFZ of multiple working faces,which provides a scientific basis for further exploring the development law of the overlying rock in underwater coal mining and ensuring the safe mining of coal seams at close distances.

Numerical Simulation on the Distribution Evolution of Overburden Fractured Zone in Coal Mining and its Visual Detection

2012 ◽  
Vol 170-173 ◽  
pp. 842-846 ◽  
Author(s):  
Tong Bin Zhao ◽  
Chang Lei Liu ◽  
Zi Yi Xiao
Keyword(s):  
Coal Mining ◽  
Fracture Zone ◽  
Distinct Element ◽  
Mining Area ◽  
Fractured Zone ◽  
Detection Technology ◽  
Fracture Development ◽  
Mining Conditions ◽  
Simulation Results ◽  
Mining Coal

Based on the mining conditions of Muchengjian Coal Mine in Beijing, the evolution process of the overburden fractured zone was simulated by the distinct element software UDEC. The simulation results show that with the increase of the mining area, fractured expansion space continues to increase upward and is arched distribution. The fracture changes significantly during primary mining and develops slowly latterly. It reaches steadily 8 times thickness of mining coal eventually. The author uses drilling camera detection technology for detecting destruction of overburden and the development situation of the fracture. Based on the results of detection, overburden fracture can be divided into mild fracture zone, moderate fracture zone, and severe fracture zone according to the fracture degree. The fracture develops unevenly in boreholes and shows that the fractured zone and complete zone appeared alternately. The simulation results have a good agreement with the measured data. And the height of stress arch is suit for the upper limit of fracture development, which can be provided guidance for coal mining in the similar conditions.

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