Variability Analysis of Undrained Shear Strength for Reliability-Based Design

Description of the spatial variation of compositional and mechanical soil parameters is often paramount in site characterization of geotechnical design and analysis. The values of the parameters themselves largely depend on in-situ state factors which are related to spatial locations. Also, for large-scale engineering projects such as earth dams or highways, it is generally expected that heterogeneous site characteristics will be revealed by investigations at spatially distant locations. Currently, most Reliability-Based Design methods are based on the second-moment statistics (mean and variance). However, they are unable to adequately describe the spatial variation of soil properties. In this paper, spatial correlation analysis is developed to evaluate the undrained shear strength profile at a location in Warrensburg in Missouri, where undisturbed samples were taken from Shelby tubes and undrained shear strengths were determined through the unconsolidated undrained triaxial hear strength (UU) tests.