Gas Outburst Prediction Research Articles

Research on gas irradiation feature of tectonic coal

Using gas-diffusion experimental installation created by Chongqing institute of coal science research institute, in different pressure conditions, studied the rule of gas diffusion in tectonically coal. Got the characteristics of the gas diffusion in tectonically coal by analysis of the experimental data, and provided the basis for the gas outburst prediction and estimate the gas emission on the working face.

Bayesian discriminant analysis for prediction of coal and gas outbursts and applicatio

Based on the principle of Bayesian discriminant analysis, we established a model of Bayesian discriminant analysis for predicting coal and gas outbursts. We selected five major indices which affect outbursts, i.e., initial speed of methane diffusion, a consistent coal coefficient, gas pressure, destructive style of coal and mining depth, as discriminating factors of the model. In our model, we divided the type of coal and gas outbursts into four grades regarded as four normal populations. We then obtained the corresponding discriminant functions through training a set of data from engineering examples as learning samples and evaluated their criteria by a back substitution method to verify the optimal properties of the model. Finally, we applied the model to the prediction of coal and gas outbursts in the Yunnan Enhong Mine. Our results coincided completely with the actual situation. These results show that a model of Bayesian discriminant analysis has excellent recognition performance, high prediction accuracy and a low error rate and is an effective method to predict coal and gas outbursts.

Technology and method of coal and gas outburst prediction during coal geological exploration

During coal resource exploration, structural deformed coal can be distinguished using geophysical well logging, and also can be predicted through the analysis of thickness of coal seam and its variations, and through the analysis of lithology, thickness and mechanics property of the roof and the floor of the coal seam and their variations. In-situ stress state and extent of deformation of the coal seam can be obtained from analysis of geological structure, structure curvature of the floor contour map of coal seam, and stress numerical simulation. In addition, we can obtain the measured gas content and pressure of coal seam directly from measures, and indirectly from the prediction means of gradient of gas content and pressure of the coal seam, explanation of geophysical data. Based on the coupling analysis of gas content, coal mechanical properties and stress state, we put forward technology and method to prediction of outburst zone of coal and gas.

An incorporate genetic algorithm based back propagation neural network model for coal and gas outburst intensity prediction

The traditional GABP model used in complex coal and gas outbursts prediction, which trains the back-propagation neural networks (BPNN) by Genetic Algorithm (GA), is provided with some limitations, such as massive time-consuming, optimal stop condition of GA pretreatment indeterminacy, independency and complex task of great importance. To overcome these problems, a new method of coal and gas outbursts intensity prediction by Incorporate Genetic Algorithm Based Back Propagation Neural Network (IGABP) is applied to determine parameters of BPNN automatically and propose an efficient GA which reduces its iterative computation time for enhancing the training capacity of BPNN. First, improved GA is based on single population model among continuous generation model and used the modified self-adapted crossover rate, crossover strategy, self-adapted stop criterion, as well as special survival condition. Second, BP operator is introduced into the evolution of GA operations, improving the standard GA optimization of random search and self-guiding optimization searching. To show the validity of the proposed method, we compare it with traditional GABP and IGABP using a dataset. The results show that the IGABP model can effectively overcome the inadequacies of the traditional model, its operating efficiency and forecast performance are improved significantly.

Application of the catastrophe progression method in predicting coal and gas outburst

Based on catastrophe theory, we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines. According to the major factors affecting coal and gas outbursts, we built a comprehensive evaluation index system and a coal and gas outburst prediction model. In addition, we performed a standard transformation for each index system; based on the degree the various indices affect the risk of an outburst, to make the data dimensionless. Based on the outburst data from eight mines, we determined catastrophe progression values and verified these values. The results show that: 1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts; 2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts, the predicting accuracy rate can be as high as 87.5%; 3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values, calculated based on these factors, can be used effectively to predict the risk of outbursts in coal mines.

Matter-elements model and application for prediction of coal and gas outburst

The theory and method of extenics were applied to establish classical field matter elements and segment field matter elements for coal and gas outburst. A matter-element model for prediction was established based on five matter-elements, which included gas pressure, types of coal damage, coal rigidity, initial speed of methane diffusion and in-situ stress. Each index weight was given fairly and quickly through the improved analytic hierarchy process, which need not carry on consistency checks, so accuracy of assessment can be improved.

Application of dynamic set-pair analysis in coal and gas outburst prediction

Analyzed the factors which affected the coal and gas outburst, then established the corresponding indicator system. Built a dynamic set-pair analysis prediction model which combined of Markov model and set-pair analysis model, and then it applied to coal and gas outburst prediction. Finally, compared the prediction results with the actual results. As provided a reference to the coalmine in safety decision-making. The research results indicate that there are four districts in high dangerous level, two districts in middle level and one district in low level, which consistent with the actual situation; the dynamic set-pair analysis model has a good effect in predicting coal and gas outburst. Especially in the continuous time intervals, according to the data of mined exploration and the connection degree analysis, we can deduce the dangerous levels of unexplored districts from the historical data. In different districts, the relevant indicators can be adjusted accordingly, so as to enhance the accuracy of the prediction.

Concept of prediction of rock and gas outburst : Cyrul, T Int J Geotech Geol EngngV10, N1, March 1992, P1–17

Concept of prediction of rock and gas outburst : Cyrul, T Int J Geotech Geol EngngV10, N1, March 1992, P1–17

A concept of prediction of rock and gas outbursts

The paper presents the prediction and modelling of rock and gas outbursts, since these are good examples of multivariable hazards in rock masses. A critical evaluation of outburst modelling is discussed and the need for system modelling of complex natural hazards is pointed out. The concept of an outburst as an event in a random field is presented. Within this conceptual framework a non-physical approach to outburst prediction, making use of measured data, is demonstrated. The approach uses the cause-effect ‘black box’ scheme to study relations between the causes and effects of outbursts. The system is assumed to be described by relations of a monotonic type, between causes and effects of outbursts. These assumptions are verified using data from the Lower Silesian Coal Basin (Poland).

Coal metamorphism and prediction of gas outburst in Nangtong coalfield, Sichuan province : Huang Kexing; Tan Yongjie Proc International Symposium on Modern Mining Technology, Taian, October 1988P470–481. Publ. Taian: Shandong Institute of Mining and Technology, 1988

Coal metamorphism and prediction of gas outburst in Nangtong coalfield, Sichuan province : Huang Kexing; Tan Yongjie Proc International Symposium on Modern Mining Technology, Taian, October 1988P470–481. Publ. Taian: Shandong Institute of Mining and Technology, 1988

The relationship between acoustic emission and permeability of rock under stress

The results of research into an assessment of the applicability of high-frequency acoustic emission techniques to the prediction of gas outbursts are reported. Simultaneous measurements of acoustic emission and permeability under triaxial compression have been conducted on outburst-prone sandstone. The results show that the changes in acoustic emission activity and permeability occur together at the dilatancy stage. This relationship was considered theoretically. The agreement between the theoretical and experimental results shows that the high-frequency acoustic emission method is very promising for predicting gas outbursts. The high-frequency acoustic emission measurements in the field, at Polish collieries, have been successfully interpreted in terms of permeability changes.

1. Rock mechanics activities in Japan

This paper provides a review of the rock mechanics activities in Japan. After a short history of the development of rock mechanics geotechnical features of the geology and industrial activities relating to rock mechanics are indicated. In terms of the geotechnical features in mines and construction sites of important projects, recent research activities in several research institutes are briefly reviewed. The present state of rock mechanics education in departments of mining and civil engineering at the universities is given, and it is suggested that the interaction between various related special fields should be promoted more actively. The features and results of rock mechanics research activities in the field of mining and civil engineering during the last 5 years are classified into eight areas and described briefly. Many research activities in mining have been conducted for prediction and prevention of rock bursts and/or gas outbursts, while the most important developments and research activities in civil engineering have been accomplished in the field of tunnelling, that is, the effect of rock bolts and sprayed concrete as tunnel support have been evaluated by various field measurement techniques, and some design methods for tunnel support have been proposed. New fields in the application of rock mechanics are being developed and some new research projects are being actively conducted.

831138 New method of prediction of gas and rock out-bursts at the stage of current prediction (in Polish) : Przegel Gorn, V37, N12, Dec 1981, P574–585

831138 New method of prediction of gas and rock out-bursts at the stage of current prediction (in Polish) : Przegel Gorn, V37, N12, Dec 1981, P574–585

New method of local prediction of gas and rock outbursts (in Polish) : Gil, M; Swidzinski, A Przegl Gorn, V37, N9, Sept 1981, P494–502

New method of local prediction of gas and rock outbursts (in Polish) : Gil, M; Swidzinski, A Przegl Gorn, V37, N9, Sept 1981, P494–502