Decision System Of Coal Mining Roadway Support Design Based On CBR

Rational selection of supporting parameters of coal mining roadway is one of important factors influencing the normal performing of coal mining workface, also is one of the important safeguards of safety in coal mine production. As influencing factors of choosing coal mining roadway supporting parameters are uncertain and complex, and some parameter values are more difficult to obtain, it is not satisfactory and effective to choose the support parameters by common methods such as theoretical calculation, numerical simulation, and similar material simulation. In recent years, with the rapid development of computer technology, many researchers of universities and institutes continuously try to apply expert system and decision support system to roadway support design and have acquired many achievements, which improve efficiency and effect. But with some shortcomings in traditional rule reasoning mechanism, such as bottleneck of knowledge acquisition, difficult in updating and maintenance of rule base, poor flexibility and adaptability and so on, these achievements have not been put into wide application.Therefore, this paper studies the coal mine roadway supporting decision-making system based on case-based reasoning, to overcome such difficulties as in traditional surrounding rock classification and rule acquisition, and to offer a new way to establish coal mining roadway support intelligent decision system. The study also expands the application fields of case-based reasoning technology.From the basic principle of case-based reasoning, this paper explores case representation, case retrieval, calculation method of case similarity, how to determinate the attribute weights of case, case modification technology, case learning and maintenance, based upon those explorations, combining the characteristics of coal mining roadway support parameter selection, the coal roadway supporting decision-making system based on case-based reasoning model has been established. On the basis of collecting numerous mining roadway support cases with parameters of their surrounding rock, employing the statistical analysis method, this paper analyzes the physical and distributional law of mechanical parameters of coal roadway surrounding rock and the relationship between the parameters. Results show general laws of the mining roadway surrounding rock parameters are as follows:(1) the poisson's ratio, density of the surrounding rock and the internal friction angle show a better standard normal distribution;(2) the compressive strength of surrounding rock has obvious positive correlations to tensile strength cohesion and density, but has weaker correlations to elastic modulus, poisson's ratio, internal friction angle;(3) elastic modulus of mudstone and siltstone increase with the gradual increase in buried depth, while the poisson's ratio shows the tendency of decreasing with the increase in buried depth. And according to the specific condition of lack of roadway surrounding rock parameters, the algorithm of parameter selection of surrounding rock is proposed based on similarity of rock feature description text and correlation of rock parameters, moreover, surrounding rock parameters database system for coal mining roadway is constructed.Finally, using object-oriented programming language and SQL Server2000database, coal mining roadway supporting decision system based on CBR has been developed, which can function properly in mining roadway support parameters selection, data analysis of mine ground pressure monitoring and so on; Further, despite the inadequate cases, the mining roadway support parameters selection engineering tested in the decision system still get the satisfactory results.