Geotechnical engineering judgment in reliability analysis of slope stability

摘要

Traditional geotechnical engineers acknowledge that they deal with an uncertain world. They also worry that engineering judgment might fade away if one puts emphasis on risk analysis. Reliability theory provides a framework for establishing appropriate factors of safety and leads to a better awareness of the relative importance of parameters. Our concern is to contribute to the understanding of limit equilibrium slope stability analysis by means of reliability theory. A first study is undertaken in order to investigate the effect of variation of the correlation coefficient between cohesion c' and friction Φ' on the Hasofer-Lind reliability index β_(HL). In a second study multiple correlated shear strength parameters (c',Φ') as well as autocorrelated are considered. The effect of correlation, autocorrelation and coefficient of variation of random variables on reliability index and probability of failure is made clear. Ignoring autocorrelation proves to be conservative.