Risk based decision making in highway slope geometry design

摘要

Soil uncertainties should be considered in the safety and economic evaluation of geotechnical structures. The impact of uncertainties in risk assessment help engineer in deciding a safer and economically feasible design of geotechnical structures. This paper studies the effect of red clay soil strength uncertainties on the highway excavated slope geometry designs. Different slope geometries are considered: slope angles of 27, 34, 45 and 63 degrees and slope heights of 5 m, 10 m and 15 m. The probabilistic analysis of slope stability is conducted using SLOPE/W to obtain the probability of failure, as well as the failed soil mass volume. The resulting probabilities are used in the quantitative decision making analysis on slope geometries. The Expected Monetary Value (EMV) derived from the construction costs, the repair costs, as well as the highway closure losses for different Levels of Service, is used in the analysis. The decision-making analysis results provide an overview of how the consequences of slope failures determining the decisions made. The consequences of slope failure indicate the design should lean on the gentle slope.