Effect of uncertainties in geometry, inter-layer boundary and shear strength properties on the probabilistic stability of a 3D embankment slope

This paper investigates the influence of three forms of uncertainty on the probabilistic stability of an idealised 3D embankment slope. These are: 1D spatial variability in the external geometry of the slope along its length, 2D spatial variability in the depth of the boundary between the embankment material and the foundation layer, and 3D...

On worst-case correlation length in probabilistic 3D bearing capacity assessments

Correlation length or scale of fluctuation (SOF) is often used as a primary parameter in defining the spatial correlation characteristics of varying soil properties. However, geotechnical site investigations are rather limited so that proper determination of correlation length is not always possible. The concept of a worst-case correlation...

Uncertainty Tracking and Geotechnical Reliability Updating Using Bayesian Networks

Bayesian networks are proposed as a tool to integrate reliability and influential variables relating to the slope stability of an idealized embankment. The site investigation (extent) and slope geometry, as well as the material properties and their spatial variability, are considered within a Bayesian network. The random finite element method ...

Modified Semi-Analytical Method for 3D Slope Reliability

An improved method for the reliability analysis of 3D slopes has been proposed based on the semi-analytical method of Vanmarcke (1977). Comparing the predicted responses of an idealised 3D slope obtained by the more general, albeit computationally intensive, random finite element method (RFEM), and the original semi-analytical method showed that...

Observations and Considerations Regarding Estimating Horizontal Scales of Fluctuation around Linear Infrastructure

Measuring soil variability has many challenges. One of the challenges is soil deformation, which can change the spatial correlation structure arising from the original geological processes. In particular, this is important in the assessment of existing structures. In this paper, the effect of existing structures on the horizontal spatial...

On characteristic values and the reliability-based assessment of dykes

A case study involving the assessment and re-design of an existing dyke, founded on a layered soil, has compared deterministic analysis based on 5-percentile property values and a reliability-based random finite element analysis consistent with the requirements of Eurocode 7. The results show that a consideration of the spatial nature of soil...

Reduction of slope stability uncertainty based on hydraulic measurement via inverse analysis

The determination of slope stability for existing slopes is challenging, partly due to the spatial variability of soils. Reliability-based design can incorporate uncertainties and yield probabilities of slope failure. Field measurements can be utilised to constrain probabilistic analyses, thereby reducing uncertainties and generally reducing...

Probabilistic Analysis of Velocity Distribution under Earth Embankments for Piping Investigation

Piping has been attributed as a major cause of dam and embankment failures. Current national prediction models to predict piping use the hydraulic gradient between the upstream and downstream water levels as an indicator. They are deterministic and take no account of preferential pathways. However, piping usually initiates from a discrete...