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...

Evaluating residual dyke resistance using the Random Material Point Method

Due to a lack of large deformation dyke assessment models, primary failure mechanisms, such as inner slope failure, are often used as a proxy to assess the probability of failure of a dyke. However, a dyke continues to fulfil its main function unless, or until, flooding occurs. The Random Material Point Method (RMPM) is used here to investigate...

Influence of Residual Dyke Strength on Dyke Reliability Using the Random Material Point Method

The material point method (MPM) is used to model both rotational and horizontal sliding failure mechanisms of dykes under external (water) loading. To model the different failure mechanisms, an external hydrostatic water pressure has been applied on the canal side of the dyke by applying a newly developed boundary condition. The boundary...

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 ...

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...

Sequential reduction of slope stability uncertainty based on temporal hydraulic measurements via the ensemble Kalman filter

A data assimilation framework, utilising measurements of pore water pressure to sequentially improve the estimation of soil hydraulic parameters and, in turn, the prediction of slope stability, is proposed. Its effectiveness is demonstrated for an idealised numerical example involving the spatial variability of saturated hydraulic...

Technical feasibility of a Dutch radioactive waste repository in Boom Clay: Geomechanical validation

OPERA-PU-TUD321d<br/>Radioactive substances and ionizing radiation are used in medicine, industry, agriculture, re- search, education and electricity production. This generates radioactive waste. In the Netherlands, this waste is collected, treated and stored by COVRA (Centrale Organisatie Voor Radioactief Afval). After interim storage for a...

Technical feasibility of a Dutch radioactive waste repository in Boom Clay: Tunnel crossings

OPERA-PU-TUD321b<br/>Radioactive substances and ionizing radiation are used in medicine, industry, agriculture, re- search, education and electricity production. This generates radioactive waste. In the Neth- erlands, this waste is collected, treated and stored by COVRA (Centrale Organisatie Voor Radioactief Afval). After interim storage for a...

Combined effect of hysteresis and heterogeneity on the stability of an embankment under transient seepage

The stability of most earth embankments is strongly influenced by the water content of the soil. The water content directly influences the suction or pore pressure in the soil, as well as the mass of material, thereby affecting the stress state and strength, and leading to changes in the stability. These aspects are coupled by the so-called soil...

Uncertainty reduction and sampling efficiency in slope designs using 3D conditional random fields

A method of combining 3D Kriging for geotechnical sampling schemes with an existing random field generator is presented and validated. Conditional random fields of soil heterogeneity are then linked with finite elements, within a Monte Carlo framework, to investigate optimum sampling locations and the cost-effective design of a slope. The...

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...

Three Dimensional Discrete Failures in Long Heterogeneous Slopes

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...

A numerical and reliability-based investigation into the technical feasibility of a Dutch radioactive waste repository in Boom Clay

OPERA-PU-TUD311<br/>The Onderzoeks Programma Eindberging Radioactief Afval (OPERA) is the third national research programme for the geological disposal of radioactive waste in the Netherlands, operating during the period 2011 to 2016. This document is the final report of Work Package 3.1, where the principal technical feasibility of the current...