Feasibility study of fuzzy method in slope stability analysis of earth dams with respect to the uncertainty of geotechnical parameters

The stability of earth dams is assessed through safety factors, indicating stability if they exceed one. Due to soil property uncertainties, fuzzy logic tools seem suitable for slope stability analysis. Uncertainties in parameters like unit weight, cohesion, and internal friction angle can be encompassed by fuzzy set theory. This study employs fuzzy set theory to analyze slope stability factor of safety, considering the varied materials and soils in earth dams. Information and parameters were gathered, and slopes were modeled using Slide (v. 6) software. Shear strength parameters and safety factors were categorized based on results and expert opinions, defining ranges for each. MATLAB software applied fuzzy logic rules to relate inputs (unit weight, cohesion, friction angle) to the output, factor of safety. Comparing results from probabilistic and fuzzy methods revealed close numerical alignment. The fuzzy method, with adaptable rules accommodating different conditions, yielded quicker and more accurate safety assessments, assuming specific data inputs. Overall, the fuzzy approach offers flexibility, facilitating quicker and more accurate determinations of safety factors, albeit requiring specific data assumptions.