Three Dimensional Discrete Failures in Long Heterogeneous Slopes

Three Dimensional Discrete Failures in Long Heterogeneous Slopes

Li, Y.
Hicks, M.A.
Vardon, P.J.

2015-10-14

Long slopes with variable material properties have a variety of different failure modes that are affected by the correlation distances of the material properties and the geometry and total length of the slope. This work follows previous research examining the consequences of increasing slope length, in which analyses were limited by the computational capacity. In this work a long slope (500 m) in a clay, characterised by a spatially varying undrained shear strength, was analysed using the random finite element method (RFEM). Random fields, to simulate the spatial distribution of the strength parameters, were generated and mapped onto finite element meshes, that were used in subsequent strength reduction analyses as part of a Monte Carlo simulation. This involved different, but equally likely, random fields to gain a probabilistic description of the distribution of safety factors and failure mechanisms. A hypothetical study of a slope cut in clay, with an intermediate horizontal correlation distance of the strength parameter, was carried out to investigate how the slope failure develops in a heterogeneous soil. In contrast to previous work, this paper emphasises the quantification of discrete failures. Hence a simple procedure has been developed to quantify the number of discrete failures in a long soil slope. It was found that, although multiple failures are possible for very long soil slopes, a single localised failure still has the greatest likelihood, as is more generally observed in practice. Due to the high computational requirements for a probabilistic analysis of such a physically large problem, Grid computing technologies were used to conduct the investigation, meaning that 1 year of computational analysis could be undertaken in a single day.

discrete failure
finite elements
heterogeneity
long slope
reliability

http://resolver.tudelft.nl/uuid:ad5e601b-8f6f-4623-99e1-9faf24076102

https://doi.org/10.3233/978-1-61499-580-7-677

Conference proceedings

conference paper

(c) 2015 The Authors and IOS Press, Creative Commons CC-BY