An evaluation method of open-pit slope stability based on Poset theory

To achieve an objective and reasonable judgment on slope stability, the partially ordered set (Poset) theory is applied to the slope stability evaluation against the engineering background of an open pit slope. From the four aspects of rock mass structural characteristics, slope morphology, environment conditions and engineering conditions, 24 typical evaluation indices such as cohesion, internal friction angle, elastic modulus and Poisson’s ratio are selected. Based on the Poset theory, a Poset evaluation model is established. According to the slope stability evaluation indices and the risk grade classification criteria, the slope stability risk grade is divided into four grades: stable (Grade I), generally stable (Grade II), slightly stable (Grade III) and unstable (Grade IV). The index data are normalized and the weight ranking information is used. Implicit weighting is carried out by means of accumulation. The comparison relation matrix, the Hasse matrix and the Hasse diagram are constructed for each factor layer and comprehensive index layer, respectively. This method was utilized to evaluate the risk grade of an engineering example, determine the slope risk grade, and compare with the actual situation. The results show that the slope to be evaluated is generally stable (Grade II) under the comprehensive evaluation indices of various factors, and the assessed stability condition is consistent with the actual situation. These verify the rationality and applicability of the proposed method and provide a new insight for accurately identifying the stability condition of open-pit slopes.