Quantitative evaluation of geological structure complexity based on AHP-entropy weight coupling method

The complexity of the geological structure of the mine field will not only affect the reasonable layout of the working face, but also cause geological disasters such as mine water damage when the abnormal geological structures such as faults have water conductivity. In order to make a scientific and accurate quantitative evaluation of the structural complexity of the well field, the Shaliang well field in Miaohagu mining area of the Jurassic coalfield in northern Shaanxi was taken as the research object. On the basis of fully understanding the geological conditions of the mine field, combined with the development of well field structure revealed by existing drilling data and geophysical data in the study area, the three main controlling factors, fault fractal dimension value, fault strength index and fault density, were used to quantitatively evaluate the complexity of geological structure in Shaliang minefield. Analytic hierarchy process (AHP) has a strong subjectivity in weight assignment, which affects the accuracy of the research results to a certain extent. Entropy weight method is an objective weighting assignment method, which overcomes the disadvantage of strong subjectivity. Therefore, in this study, the weights of the main controlling factors of geological structure complexity were comprehensively obtained by using the coupling method of analytic hierarchy process and entropy method, and the quantitative evaluation model of mine structural complexity was established and the proposed quantitative evaluation model was used to quantitatively evaluate the structural complexity in the study area. On this basis, according to the proposed quantitative evaluation model, the complexity within the scope of Shaliang minefield is divided into four grades, including complex structural area, relatively complex structural area, medium structural area and simple structural area. It provides a new theoretical method for quantitative evaluation of geological structural complexity. The research results provide a new method for quantitative evaluation of geological structural complexity. The purpose of this paper is to provide some guidance for the efficient and safe production of the mine.