Research on Slope Stability Evaluation Based on Improved Set Pair Analysis Method: A Case of Tonglvshan Open‐Pit Mine

Abstract

In this paper, combined with fuzzy analytic hierarchy process (FAHP), information entropy theory, and set pair analysis (SPA) theory, an improved set pair analysis model (EFAHP-SPA) for open-pit mine slope stability evaluation based on entropy method and FAHP is proposed. Taking the east-side slope of Tonglvshan north open-pit mine in Daye as an example, the proposed method is verified. First, an open-pit mine slope stability evaluation index system with 14 indicators in 4 categories, namely the topography and geomorphology, geological structure, hydrogeology, and other factors, have been constructed. Second, the objective weight and subjective weight of each evaluation index are calculated by entropy and fuzzy analytic hierarchy process, and then the comprehensive weight of the evaluation index is estimated based on subjective weight and objective weight. Afterward, the single-index connection degree between the evaluation index and the evaluation standard of the secondary subsystem is evaluated considering the improved set pair analysis theory, and the comprehensive connection degree of the system is obtained by combining it with the comprehensive weight of each evaluation index. Finally, the confidence criterion is established to discern the risk grade of slope stability in the east-side slope of the north open pit in Daye Tonglvshan mine. Moreover, case studies and comparisons of the proposed model with fuzzy comprehensive evaluation method and Entropy-SPA model were performed to confirm the validity and reliability. The results show that the evaluation results of the proposed EFAHP-SPA model are consistent with the actual situation of open-pit mines and the evaluation results of entropy-SPA model and are somewhat different from those of fuzzy comprehensive evaluation method. It indicates that the proposed EFAHP-SPA evaluation model can objectively evaluate the slope stability of the open-pit mine.

An Improved Unascertained Measure-Set Pair Analysis Model Based on Fuzzy AHP and Entropy for Landslide Susceptibility Zonation Mapping

“…SPA theory, proposed by Zhao Keqin [32], is a systematic analysis method used to deal with the "determination-uncertainty problem". The core idea is to regard the certainty and uncertainty of the problem studied as a whole system, using the identity degree and contrary degree to describe the certainty of the system, using the discrepancy degree to describe the uncertainty of the system and to quantitatively describe the relationship between the certainty and uncertainty of the system from the three aspects of similarities and differences [35,36].…”

“…The slope top elevation of the stope is 30-50 m, the lowest elevation of the pit bottom (southern open-pit) is −175 m and the slope angle of the stope is 46-56.5 • . Highway 3 runs between the eastern slope of the North Open Pit Mine and the ancient copper Mine Site Museum [35,45]. latitude 30°04′21″-30°05′46″, the mining area is approximately 5.61 km .…”

“…The slope top elevation of the stope is 30-50 m, the lowest elevation of the pit bottom (southern open-pit) is −175 m and the slope angle of the stope is 46-56.5°. Highway 3 runs between the eastern slope of the North Open Pit Mine and the ancient copper Mine Site Museum [35,45]. Located in the south bank of the middle and lower reaches of the Yangtze River, the study area is a typical subtropical continental monsoon climate, characterized by cold winters and hot summers, four distinct seasons, abundant rainfall and annual average rainfall of 1382.6 mm.…”

“…The area is rich in mineral resources, complex geological structure, a large number of copper, iron, gold and other metallic mineral resources and limestone, lapis lazuli, marble and other non-metallic mineral resources. It is an important part of the middle and lower reaches of the Yangtze River metallogenic belt [35,45].…”

“…However, due to the complexity of different regional geological environments, the existing landslide susceptibility evaluation lacks unified criteria for the selection of LCF [9,49]. In order to obtain a relatively reasonable LCF, the LCF can be determined according to the engineering geological characteristics and scale of the study area, expert knowledge reserve or experience, scientific and technological literature review [14,35,50] and data availability. Based on the above criteria, on the premise of ensuring the objectivity and accuracy of the selected evaluation factors, this study preliminarily selected 10 evaluation index factors in the four categories of topography, geological conditions, hydrological environment and human engineering activities by combining the field geological survey and literature review.…”