1、Fuzzy evaluation on geological conditions of coal seam in ChinaZhang Dongsheng, Zhang Xianchen & Yan XuefengChina University of Mining & Technology, Xuzhou, Jiangsu, P. R. ChinaDszhang123Abstract The geological conditions of coal seam are evaluated quantitatively by using fuzzy method and from point
2、view of coal mining. According to the evaluation results, decision-making on mining techniques, mining programming and design, production management can be carried out effectively. The latest developments in China are introduced. The evaluation contents, the structure and index system of evaluation
3、factors, the membership functions and weights of evaluation factor, evaluation model and reliability are stated in detail. The effective application of fuzzy evaluation in the prediction of coal face output is introduced emphatically. Fuzzy evaluationon geological conditions of coal seam is the basi
4、c work that ensures a mine run efficiently, safely and steadily . Keywords:Fuzzy evaluation; geological conditions; evaluation 1 INTRDUCTION To exploit the coal resource rationally means that the mining technical level and the relevant technical decisions are suitable for the characteristic and diff
5、erence of coal geological conditions. If the evaluation is far below or above the actual geological conditions, it is unfavorable to make the most of the coal natural superiority and easy to make false technical decisions. So, it is very important to improve mining effects and economic benefits that
6、 the geological conditions are evaluated appropriately and the corresponding measures are taken. 2 CONTENTS OF FUZZY EVALUATION Based on the coal mining experience and rules summarized by widely investigation, the evaluation on geological conditions of coal seam should be taken by not only studying
7、the influence of main factors to the selection of coal mining technology and mining effects, but also constructing a comprehensive supported by National Natural Science Foundation of China（NSFC） (50374065)，NSFC for extinguished scholars (50225414) evaluation model with multi-levels and multi-factors
8、 by the use of mining theory, fuzzy mathematics andAnalytic Hierarchy Process (called AHP for short), etc. In addition, the evaluation reliability should be considered in the application of evaluation results. So, the complete contents of fuzzy evaluation should include: (1) Investigating the experi
9、ence and material of geological conditions, coal mining technology, technical effects, and safety state of face extraction in typical mining district. (2) Determining the structure of evaluation factors and the index system of geological factors, the membership functions and the weights of evaluatio
10、n factors, and establishing the fuzzy evaluation model by summarizing the influence of geological factors to coal mining technology and using the methods of fuzzy mathematics, etc. K(3) Dividing the coal seam into many smaller blocks ij (i is coal seam number, j is block number.)Kijaccording to geol
11、ogical reports, and making pre-mining evaluation of the blocks to get the pre-mining evaluation value Pij. K(4) Making the second evaluation of typical blocks ij having been mined to get the evaluation valuePPij Pij according to the geological report and supplementary geological material after minin
12、g, is more suitable to practice. R = P(5) Analyzing the reliability of pre-mining evaluation, P( R is reliability index of the pre-mining evaluation K ), R 1. (6) Making evaluation on the blocks, based on the Pij and the Rij , the evaluation value of the blocks is:P0 = P Ri(7) Modifying the evaluati
13、on model or making a new evaluation according to its application and actual requirement. 3 STRUCTURE AND INDEX SYSTEM OF EVALUATION FACTORS The structure of evaluation factors reflects the connotation of evaluation. Its establishment should consider not only the general and specific difficult geolog
14、ical conditions, but also the principles of systematicness, feasibility and simplicity for the evaluation factors and indices obtained easily. Fuzzy evaluation on geological conditions of gently inclined or inclined coal seam in China consists of the evaluations for the general geological conditions
15、 and for the specific difficult geological conditions. The evaluation for the general geological conditions includes seven factors of geological structure, thickness of coal seam, stability of coal seam, pitch of coal seam, roof and floor of coal seam, hardness of coal seam and block dimension. The
16、evaluation for the specific difficult geological conditions includes the other four factors of gas geology, hydrogeology, coal spontaneous combustion and the others besides the seven factors mentioned above. Furthermore, the geological structure contains three basic factors of fault, fold and magma. The stability of coal seam contains three basic factors of minability of coal seam, variability of coal seam and band coefficient. The roof
