| The use of probability analysis is an important tool in geotechnical engineering to evaluate the uncertainties related to parameters and modeling. With the advances in software and the use of Monte Carlo, the ease of performing probabilistic analysis should be considered in design, especially for critical structures that may cause significant and catastrophic losses. This purpose of this research is to provide a practical, real-life case study to assist practicing geotechnical engineers in applying probabilistic slope stability modeling. The case study location incorporates the earthen levees of reach Lake Pontchartrain and Vicinity (LPV) 146 in St. Bernard, Louisiana, prior to the 2010 construction. Literature research was first conducted on the lessons learned and history of risk analysis within the federal government, uncertainties of geotechnical engineering, statistical methods for evaluating geotechnical parameters, and probability models for slope stability. The study evaluates parameter and spatial variation for probability analysis of slope stability using First Order Second Moment with Taylor Series expansion and Monte Carlo methods. Slope stability performance is based on Spencer's method using SLOPE/W. Parameter and spatial variation considerations include statistical analysis and data trends of unit weight, shear strength ratio and shear strength as well as scale of fluctuation and how these impact the probabilistic slope stability analysis. The results of the study are also compared with those generated from the risk analysis performed by the Interagency Performance Evaluation Task Force. |
