scholarly journals Determination of the key parameters of high‐position hard roofs for vertical‐well stratified fracturing to release strong ground pressure behavior in extra‐thick coal seam mining

2020 ◽  
Vol 8 (6) ◽  
pp. 2216-2238 ◽  
Author(s):  
Chao Pan ◽  
Binwei Xia ◽  
Bin Yu ◽  
Peng Yu ◽  
Yafei Luo ◽  
...  
Keyword(s):  
Coal Seam ◽  
Thick Coal Seam ◽  
Vertical Well ◽  
High Position ◽  
Pressure Behavior ◽  
Ground Pressure ◽  
Seam Mining ◽  
Strong Ground

Study on the Structure Characteristics and Ground Pressure Behavior of Overlying Strata with Shallow Buried Coal Seam

2011 ◽  
Vol 255-260 ◽  
pp. 3780-3785 ◽  
Author(s):  
Lei Yu ◽  
Zhi Zhong Fan ◽  
Gang Xu
Keyword(s):  
Coal Seam ◽  
Ground Subsidence ◽  
Mine Pressure ◽  
Structure Characteristics ◽  
Pressure Behavior ◽  
Ground Pressure ◽  
Working Face ◽  
Periodic Pressure ◽  
Seam Mining ◽  
Overlying Strata

The mine pressure behavior characters of shallow buried coal seam differed from both shallow seam mining and general depth seam. Mine pressure observation and numerical analysis were applied to research mine pressure behavior laws in fully mechanized face of shallow buried coal seam with thick bedrock and thin alluvium. It showed that the ground subsidence level phenomenon did not appear obviously although with obvious dynamic loading of fully mechanized face during the pressure period. The appearance was due to non-synchronized fracture from two key layers in the overlying rock layers and their interaction, which leaded to roof breaking initially and caving rocks with the form of an arch. Due to the periodic breaking and caving characteristics appearing as fully cut-down and arch alternately, the periodic pressure of shallow buried coal seam face showed as different size. The conclusion could be a reference for similar working face control.

scholarly journals Investigation on the Ground Pressure Induced by Hard Roof Fracturing at Different Layers during Extra Thick Coal Seam Mining

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Rui Gao ◽  
Jingxuan Yang ◽  
Tiejun Kuang ◽  
Hongjie Liu
Keyword(s):  
Coal Seam ◽  
Physical Simulation ◽  
Similarity Criterion ◽  
Thick Coal Seam ◽  
Failure Characteristics ◽  
Hard Roof ◽  
Ground Pressure ◽  
Working Face ◽  
Seam Mining ◽  
Roadway Deformation

The fracturing of hard roofs in different layers would result in complex ground pressure on the working face, such as supports collapsed and severe roadway deformation. However, the mechanism of the ground pressure induced by hard roof fracturing in different layers is still unclear. In the paper, a physical model of a 20 m extrathick coal seam mined with hard roofs existing was established based on the physical simulation similarity criterion. The overburden fracturing structure, abutment stress distribution, and failure characteristics of the coal body were monitored by a noncontact strain measurement system and resistance strain gauges, to reveal the mechanism of ground pressure induced by hard roof fracturing. Furthermore, on-site measurement was used to monitor and analyze the ground pressure affected by hard roofs in different levels. The results provide a theoretical basis for the control of ground pressure in extrathick coal seam mining with hard roofs.

scholarly journals Study on Mine Pressure Control by Ground Fracturing High-level Hard Rock Strata

2020 ◽  
Author(s):  
Rui Gao ◽  
Tiejun Kuang ◽  
Yanqun Zhang ◽  
Wenyang Zhang ◽  
Chunyang Quan
Keyword(s):  
Coal Seam ◽  
Energy Release ◽  
Hard Rock ◽  
Effective Control ◽  
Mine Pressure ◽  
Control Effect ◽  
Thick Coal Seam ◽  
Ground Pressure ◽  
High Level ◽  
Seam Mining

Abstract The high-level thick and hard strata are the main reason for the presence of a strong ground pressure during extra-thick coal seam mining, however, there is no active and effective control technology. This paper proposes the method of ground fracturing hard roofs, and the physical simulation was used to study the control effect of ground fracturing on the strata structure and energy release. The results showed that the ground fracturing changed the structural characteristics of the strata, reduced the energy release intensity and overburden movement spatial extent, which had a significant control effect on the ground pressure. The Datong mining area was selected as the engineering background, a ground horizontal well fracturing engineering test was conducted on site, and a 20-m-thick hard rock layer, which was 110 m vertically above from the coal seam, was determined as the fracturing target layer. On-site microseismic monitoring showed that the crack propagation length was up to 216 m, and the height was up to 50 m. On-site mine pressure monitoring showed that the roadway deformation was reduced to 100 mm, the periodic weighting characteristics of the hydraulic supports were not obvious, the ground pressure in the working face was significantly controlled, which proved the ground fracturing successful. Ground fracturing changed the breaking characteristics of the high-level hard strata, which is beneficial to ameliorate the stress concentration in the stope and provide an effective approach of hard rock control.

Application of Thick Coal Seam Mining Method Prediction Model Based on Artificial Neural Network

2014 ◽  
Vol 962-965 ◽  
pp. 242-246
Author(s):  
Wen Yu Lv ◽  
Zhi Hui Zhang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Coal Seam ◽  
Prediction Model ◽  
Coal Mining ◽  
Mining Method ◽  
Thick Coal Seam ◽  
Method Selection ◽  
Mining Method Selection ◽  
Seam Mining

Because of thick coal seam mining method selection is not only affected by coal seam geological conditions, but also limited by workers, and not fully utilization of experts` experience, the effect of tradition coal mining method selection methods are not ideal. The thick coal seam mining method prediction model based on artificial neural network (TCSMMPM-ANN) was established through the analysis of thick coal seam mining by using Levenberg – Marquardt (L-M) improved algorithm to train network, the simulation results of network test show that this model can provide a new research idea for thick coal seam mining method optimal selection and face economic and technical index prediction, it will have a broad prospect in thick coal mining.

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