On the design of bank revetments at inland waterways subjected to ship-induced water level drawdown: A probabilistic infinite slope analysis

To protect embankments along German inland waterways against local slope sliding failure caused by ship-induced water level drawdown, they are mainly secured by bank revetments. Often, large embankment sections are designed on the basis of a limited number of field and laboratory tests. Thus, uncertainties arise with regard to the mechanical and...

Numerical investigation of liquefaction susceptibility of sands considering fabric effects

Natural soil deposits may possess a highly anisotropic nature. The fabric anisotropy of soils which is induced during the soil formation process can lead to severe variation in field scale responses. Although the influence of fabric on the response of sands is well known and several advanced constitutive models have been developed to account for...

Periodic random fields to perform site response and liquefaction susceptibility analysis

Free-field site response analysis is a standard technique used to predict soil deposit dynamic response and liquefaction susceptibility. Such analyses are typically carried out by implementing periodic boundaries to guarantee the same speed of the dynamic waves travelling across them. However, when using random fields to consider the impact of...

Predicting subsurface classification in 2D from cone penetration test data

Uncertainty is inevitable in the characterisation of a geotechnical site, especially due to the inherently heterogeneous nature of the ground. In this paper, a method for characterising a subsurface with limited cone penetration test (CPT) data is proposed. The method is based on integrating predictions of CPT parameters with a probabilistic...

Machine learning for prediction of undrained shear strength from cone penetration test data

This research focuses on investigating the relative performance of a range of machine learning algorithms, namely the artificial neural network, support vector machine, Gaussian process regression, random forest, and XGBoost, for predicting the undrained shear strength from cone penetration test data. This is to assess how machine learning could...

Predicting subsurface stratigraphy using an improved Coupled Markov Chain method

Geological uncertainty can significantly influence the computed response of a geotechnical structure. For example, ignoring the presence of a weak soil layer embedded within a stronger layer and assuming a deterministic stratigraphic boundary can significantly underestimate the probability of failure. In this paper, the coupled Markov chain...

Liquefaction Assessment and Soil Spatial Variation

Soil liquefaction is investigated considering a saturated soil deposit and by implementing standard techniques of random field theory to distribute initial void ratio values and assess liquefaction risk. The soil domain is represented in a 2-dimensional (2D) random finite element model for the dynamic analysis of coupled behavior. Multiple...

Reliability-Based Partial Factors Considering Spatial Variability of Strength Parameters

The stability of six regional dyke cross-sections in the Netherlands was re-assessed using the random finite element method (RFEM), which explicitly accounts for the spatial variability of strength parameters. The RFEM assessments of the cross-sections were shown to result in significantly narrower response distributions than those obtained...

Comparison of 1D and 2D liquefaction assessment methods considering soil spatial variability

1D soil column techniques are widely used to evaluate the potential of liquefaction in a system of soil layers. This approach generally leads to large inaccuracies since (1) soil layers are hardly homogeneous and perfectly horizontal and (2) horizontal effects are neglected. To demonstrate the limitation of 1D strategies and the need for 2D...

Metamodelling for geotechnical reliability analysis with noisy and incomplete models

A kriging-based metamodelling approach for analysing the structural reliability of a sheetpile wall in a dyke is formulated. This specific problem is characterised by high target reliabilities ((Formula presented.)) in combination with a noisy and incomplete numerical model response. Starting from the original formulation of active learning...

On the reliability assessment of a controlled dyke failure

A reliability-based analysis framework, accounting for uncertainty arising from the spatial variability of soil properties, has been validated for the controlled, well-instrumented slope failure of an historic dyke in the Netherlands. Using soil property statistics derived from the results of laboratory and cone penetration test (CPT) data for...

On characteristic values for calculating factors of safety for dyke stability

Various simplified approaches are used to calculate the characteristic values of shear strength properties, which have then been used in deterministic stability analyses of a dyke cross-section. The calculated factors of safety are compared with the 5-percentile ‘system response’ of the dyke cross-section, calculated using the more exhaustive...

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...

Probability-dependent failure modes of slopes and cuts in heterogeneous cohesive soils

Improbable slope failure is addressed in the framework of reliability analysis of slopes in heterogeneous cohesive soils, as the small subset of realisations that fail without additional measures to trigger failure. The mode of these slope failures, located at the weak tail of the reliability curve, is demonstrated to differ significantly...

Efficient subset simulation for evaluating the modes of improbable slope failure

For analyzing low probability slope failures, a modified version of subset simulation, based on performance-based subset selection rather than the usual probability-based subset selection, is combined with the random finite element method. The application to an idealized slope is used to study the efficiency and consistency of the proposed...

Investigating the Influence of Conditional Simulation on Small-Probability Failure Events Using Subset Simulation

Spatial variation of soil strength parameters is a dominating uncertainty in slope stability analysis. This uncertainty can be accounted for in a stochastic description, based on a global geostatistical characterization of the soil strength parameters, which leads to a wide range of possible slope responses, of which only a small proportion...