scholarly journals An Index of Aquiclude Destabilization for Mining-Induced Roof Water Inrush Forecasting: A Case Study

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2170 ◽  
Author(s):  
Gangwei Fan ◽  
Shizhong Zhang ◽  
Dongsheng Zhang ◽  
Chengguo Zhang ◽  
Mingwei Chen ◽  
...  
Keyword(s):  
Water Level ◽  
Coal Mine ◽  
Critical Role ◽  
Water Inrush ◽  
Threshold Value ◽  
Control Measures ◽  
Assessment Index ◽  
Risk Levels ◽  
Upper Aquifer

Aquiclude plays a critical role in the occurrence of mining-induced roof water inrush in underground coal mines. This paper proposes an assessment index for the evaluation of aquiclude stability and a threshold value of water inrush from the roof, based on a case study of roof water inrush accidents in Cuimu coal mine, China. The relation between roof water inrush and water level variation in the aquifer, and the characteristics of aquiclude deformation, were studied in this assessment. Using the developed assessment criteria, the likelihood of roof water inrush was categorized into different risk levels, which were followed by a proposal for roof water inrush control measures. The main findings of this study are: a) in Cuimu coal mine, the waterbody in the bed separation between the upper aquifer and the aquiclude directly causes the inrush, and inrush occurs after the water level declines in the aquifer; b) tension-induced horizontal strains of aquiclude can be regarded as the index to evaluate the stability of aquiclude affected by underground coal mining—roof water inrush occurs when the maximum horizontal strain reaches a threshold of 10mm/m—c) based on the critical mining height for aquiclude instability, and the different thicknesses of barrier layers, high-risk zones are identified and inrush controls are proposed.

Risk Evaluation of Bed-Separation Water Inrush: A Case Study in the Yangliu Coal Mine, China

2018 ◽  
Vol 37 (2) ◽  
pp. 288-299 ◽  
Author(s):  
Qiuyu Lu ◽  
Xiaoqin Li ◽  
Wenping Li ◽  
Wei Chen ◽  
Luanfei Li ◽  
...  
Keyword(s):  
Coal Mine ◽  
Risk Evaluation ◽  
Water Inrush ◽  
Bed Separation

scholarly journals An Approach to Dynamic Disaster Prevention in Strong Rock Burst Coal Seam under Multi-Aquifers: A Case Study of Tingnan Coal Mine

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7287
Author(s):  
Xinxin Zhou ◽  
Zhenhua Ouyang ◽  
Ranran Zhou ◽  
Zhenxing Ji ◽  
Haiyang Yi ◽  
...  
Keyword(s):  
Rock Burst ◽  
Coal Mine ◽  
Water Inrush ◽  
Coal Seams ◽  
High Position ◽  
Integrated Method ◽  
Working Face ◽  
Strong Rock ◽  
And Control

In order to prevent the multi-dynamic disasters induced by rock burst and roof water inrush in strong rock burst coal seams under multi-aquifers, such as is the case with the 207 working face in the Tingnan coal mine considered in this study, the exhibited characteristics of two types of dynamic disasters, namely rock burst and water inrush, were analyzed. Based on the lithology and predicted caving height of the roof, the contradiction between rock burst and water inrush was analyzed. In light of these analyses, an integrated method, roof pre-splitting at a high position and shattering at a low position, was proposed. According to the results of numerical modelling, pre-crack blasting at higher rock layers enables a cantilever roof cave in time, thereby reducing the risk of rock burst, and pre-crack blasting at underlying rock layers helps increase the crushing degree of the rock, which is beneficial for decreasing the caving height of rock layers above goaf, thereby preventing the occurrence of water inrush. Finally, the proposed method was applied in an engineering case, and the effectiveness of this method for prevention and control of multi-dynamics disasters was evaluated by field observations of the caving height of rock layers and micro-seismic monitoring. As a result, the proposed method works well integrally to prevent and control rock burst and water inrush.

scholarly journals Karst Water Pressure’s Varying Rule and Its Response to Overlying Strata Movement in Coal Mine

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Jian Hao ◽  
Hua Bian ◽  
Anfa Chen ◽  
Jiahui Lin ◽  
Dongjing Xu
Keyword(s):  
Water Level ◽  
Water Column ◽  
Coal Mine ◽  
Simulation Experiment ◽  
Water Pressure ◽  
Water Inrush ◽  
Column Height ◽  
Karst Water ◽  
Working Face ◽  
Water Column Height

Karst water is widespread throughout China and is heavily influenced by complex geological conditions, and floor inrush of karst waters associated with coal seams is the second most common coal mine disaster in China. Due to the limitation of precision and cost of geophysical exploration technology, the volume and pressure of karst water are challenging to measure, especially during the mining process. Therefore, predicting karst pressure’s response to mining is critical for determining the mechanism of water inrush. Here, closed karst water pressure (CKWP) response to mining was studied in an innovative physical simulation experiment. In the simulation experiment, a capsule and a pipe were designed to reflect CKWP and the water level. In the experiment, the vertical stress and karst water level were monitored throughout the process of an advancing coal panel. Monitoring results show that the range of the abutment pressure was about 40 cm, and the peak coefficient value was about 2. When the working face is far away from the water capsule, the stress and water column near the water capsule have no obvious change. With the working face 10 cm from the water capsule, the stress and water column height increased significantly. When the working face was right above the water capsule, the stress and water column rose sharply and reached the maximum value. When the working face advanced beyond the water capsule, the stress and water column height declined. Through establishing a structural mechanics model, the karst water system underneath the working face is assumed to be a hydraulic press. Accordingly, the compressed area was assumed to be a piston. The karst water pressure increases sharply, while the piston is compressed, increasing water inrush risk. This discovery may help determine the water inrush mechanism from a novel point of view.

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