The Failure Probability of a Slope

The Failure Probability of a Slope

Pragosa, J.E.M.

Vrijling, J.K. (mentor)
van Baars, S. (mentor)
Jongejan, R. (mentor)

Civil Engineering and Geosciences

2005-07

There is about 18000 km of dikes in The Netherlands. Their use is to prevent the lowlands, where the inhabitants live, from flooding. Flooding is a typical high-consequence low-probability event. To study the failure probability of a dike, one of the numerical methods available, derived from the Level III probabilistic methods, is the so-called Monte Carlo simulation (MCs). The Finite Element Method (FEM) program PLAXIS is widely used to study dike stability. This dike stability can be quantified by means of the Safety Factor (SF). However, estimating the failure probability of a dike with PLAXIS is at present not possible and even if the MCs will be installed, the calculation will be time consuming. In order to overcome this problem, an easy and quick method is needed to estimate the failure probability of a dike. This project uses a study case described by a circular slip failure surface of a dike with three independent layers. Each layer is defined by its undrained shear strength with a normal distribution function. Besides MCs, an analytical solution for the SF of a slope, which is a linear combination of the soil strength for a fixed slip circle, was developed. The project compares the failure probability value obtained by both the MCs and the analytical solution. Finally, using the analytical solution, the failure probability estimation of a slope is presented by a quick and easy procedure to use with FEM.

http://resolver.tudelft.nl/uuid:c59e4024-d4ee-4a3e-b544-a03e18599c3f

TU Delft, Faculty of Civil Engineering and Geosciences, Hydraulic Engineering

Student theses

master thesis

(c) 2005 J.E.M. Pragosa