scholarly journals Study on mining the protective seam with the manless working face in coal and gas outburst mines

2009 ◽  
Vol 1 (1) ◽  
pp. 227-234 ◽  
Author(s):  
Fang Xin-qiu ◽  
Zhao Jun-jie ◽  
He Jie
Keyword(s):  
Coal And Gas Outburst ◽  
Gas Outburst ◽  
Working Face ◽  
Protective Seam

A protective seam with nearly whole rock mining technology for controlling coal and gas outburst hazards: a case study

2016 ◽  
Vol 84 (3) ◽  
pp. 1793-1806 ◽  
Author(s):  
Qiang Sun ◽  
Jixiong Zhang ◽  
Qiang Zhang ◽  
Wei Yin ◽  
Deon Germain
Keyword(s):  
Coal And Gas Outburst ◽  
Mining Technology ◽  
Gas Outburst ◽  
Protective Seam ◽  
Rock Mining

scholarly journals Coal and Gas Outburst Affected by Law of Small Fault Instability during Working Face Advance

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jianyun Lin ◽  
Yujun Zuo ◽  
Kai Zhang ◽  
Wenjibin Sun ◽  
Biao Jin ◽  
...  
Keyword(s):  
Fault Zone ◽  
Coal And Gas Outburst ◽  
Face Advance ◽  
Movement Rate ◽  
Gas Outburst ◽  
Working Face ◽  
Prediction And Prevention ◽  
Small Fault ◽  
Coal And Gas Outbursts ◽  
Overburden Strata

To analyze the effect of small faults in the working face on coal and gas outbursts, the coal and gas outburst accident in the 21431 working face was studied with the 3DEC numerical simulation method, and the main research contents were the change laws of both stresses at the small fault and the overburden strata movement rate in the small fault zone of which the drop height and the strike were designed into different groups. The results show that the risk of small fault slip increases with the advancing working face. In addition, there is a positive correlation between the risk and the small fault throw. The movement rate of overburden strata in the small fault zone increases along with the rising of the small fault throw, which increases the energy transferred to the coal seam from the surrounding rock under the effect of the small fault. Hence, the effect of small faults on the working face on coal and gas outbursts was positively correlated with the small fault throw. Under the influence of a small fault strike, the closer it is to the small fault along the dip distance at the same working face, the greater the risk will be of a coal and gas outburst. And the bigger the small fault strike is, the greater is the stress concentration degree in front of the working face and the more the elastic energy is stored and the greater is the possibility of an outburst. The paper analyzes the influence of small faults on coal and gas outbursts in the working face, which has reference significance for the prediction and prevention of coal and gas outburst disaster in the working face.

scholarly journals Mathematical equations for pressure relief angle of protective seam inclination in outburst coalmine

2020 ◽  
Author(s):  
Zhen Zhang ◽  
Gaofeng Liu ◽  
Ting Ren ◽  
Patrick Booth ◽  
Runsheng Lv ◽  
...  
Keyword(s):  
Coal And Gas Outburst ◽  
Pressure Relief ◽  
Effective Measure ◽  
Gas Outburst ◽  
Relief Angle ◽  
Protective Seam ◽  
Mathematical Equations ◽  
Seam Mining ◽  
Protective Seam Mining ◽  
The Relationship

Abstract Protective seam mining is one kind of most effective measure to reduce coal and gas outburst risk. The pressure relief angles along inclination (δm) are key parameters for evaluating the effect of protective seam mining. However, the numerical relation between δm and coal seam dip (a) is defined by discrete data and is difficult to determine δm accurately. In this study, the variations of δm with respect to seam dips are analyzed to derive analytical equations that can be used to accurately calculate δm. The relationship between δm and seam dip (a) can be expressed as parabolic or inverted parabolic curves. Mathematical equations for δm are derived by curve fitting technique. Furthermore, polynomial equations are determined as the most appropriate for δm calculation when the polynomial order is selected as 7, 6, 4 and 5 respectively. These derived equations are computationally solved and verified using actual and field test data of δm. with satisfactory consistency and accuracy. The equations are suggested as supplement and improvement for Detailed Rules on Prevention of Coal and Gas Outburst.

scholarly journals The dynamic failure mechanism of coal and gas outbursts and response mechanism of support structure

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 867-875 ◽  
Author(s):  
Mingzhong Gao ◽  
Sheng Zhang ◽  
Jie Li ◽  
Haiyun Wang
Keyword(s):  
Numerical Model ◽  
Failure Mechanism ◽  
Coal And Gas Outburst ◽  
Effective Control ◽  
Dynamic Failure ◽  
Response Mechanism ◽  
Support Structure ◽  
Gas Outburst ◽  
Theoretical Support ◽  
Working Face

In view of the common mine disasters such as coal and gas outburst caused by the destruction of gas and coal, the numerical model of RFPA-GAS software was used to establish a numerical model based on a gas outburst accident took place in return roadway of working face 15-17-16041 in Pingdingshan mine. The dynamic failure mechanism of coal and gas outburst under the conditions of different support strengths protection and unsupported conditions was analyzed. Four dynamic processes of coal and gas outburst were discussed, and the dynamic failure mechanism of coal and gas outburst was revealed. The results show that the outstanding effect of the roadway without support treatment is similar to that of the field, and the coal and gas outburst is obviously weakened for supported roadway. Which has effective control of the active support for the protrusion. When the support method is designed, the response mechanism of the coupled support structure should be considered. It provides some theoretical support for the gas outburst control.

scholarly journals Study on Plastic Zone Distribution Characteristic of Coal and Rock Mass in Excavation from Crosscut Coal

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Chengwu Li ◽  
Xiaoqian Zhang ◽  
Chengmin Wei ◽  
Yao Nie
Keyword(s):  
Rock Mass ◽  
Stress Distribution ◽  
Plastic Zone ◽  
Morphological Characteristics ◽  
Coal And Gas Outburst ◽  
Distribution Characteristics ◽  
Prevention Measures ◽  
Shape Distribution ◽  
Gas Outburst ◽  
Working Face

Coal and gas outburst is a serious disaster in the mining, and crosscut coal is the most prone to cause the coal and gas outburst. In order to study the mechanism of outburst, this paper studied the stress distribution characteristics in front of the working face in the process of rock roadway driving before implementing crosscut coal firstly. On this basis, the hypothesis of stress distribution on the “strong and soft face” of coal-rock mass was proposed. And by using the hypothesis, the mechanical equation for the parameter changes of the plastic zone in front of the working face in crosscut coal was established, and the width and morphological characteristics of the plastic zone in crosscut coal were analyzed. The results show that during the process, as the working face moves forward, the shape distribution of the plastic zone in front of the working face changes from the “semielliptical” to “semibutterfly,” And based on the distribution characteristics of plastic zone in working face in crosscut coal, modification proposals for outburst-prevention measures were proposed and provided technical support for the outburst-prevention measures and key parameters setting to prevent the coal outburst in crosscut coal.

Optimization for Prediction Indexes of Coal and Gas Outburst in Coal Roadway Excavation Working Face Based on Grey Synthetically Relational Degree

2012 ◽  
Vol 524-527 ◽  
pp. 647-652 ◽  
Author(s):  
Xiang Zeng Du
Keyword(s):  
Coal And Gas Outburst ◽  
Healthy Development ◽  
Gas Outburst ◽  
Coal Roadway ◽  
Working Face ◽  
Relational Degree ◽  
Quantitative Basis ◽  
Secondary Disasters ◽  
Reasonable Prediction ◽  
The Mathematical Model

Coal and gas outburst is a strong dynamic phenomenon in the process of coal mining, which the fierce degree and destroy effect is beyond imagination, also can cause the occurrence of secondary disasters, such as fire, gas explosion. Especially in coal roadway excavation face, it is frequent. Therefore, the reasonable prediction and evaluation for associated factors of coal and gas outburst in coal roadway excavation working face is important and guiding significant for coal production, sustained and healthy development. With the mathematical model of grey synthetically relational degree analysis, we gain quantitative analysis of six prediction indexes of coal and gas outburst, and determine the best predictors, provide quantitative basis for the selection of coal and gas outburst prediction indexes.

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