Schematization uncertainties in the macrostability safety assessment: Case study for primary dikes in the Alblasserwaard

The current macrostability safety assessment for primary river dike trajectories in the Netherlands is applied to approach the failure probability of a dike during high water events. However, in the current schematization process that is described in the Wettelijk Beoordelings Instrumentarium (WBI) to assess the macrostability, aleatory and...

Spatial variability in dike stability assessments

The safety of the Dutch dikes depends on various failure mechanisms. Macro stability, a geotechnical failure mechanism, is highly affected by differences in soil strength because the sliding plane propagates through areas of least resistance. The variations in soil properties in space, also known as spatial<br/>variability, are caused by...

Reliability Based Design Optimization on Quay Walls by re-calculating partial factors

In the years to come, the Netherlands will face a substantial challenge as over 1,500 kilometers of aging quay walls and sheet pile walls approach the end of their technical lifespan. Infrastructure managers anticipate that the necessary replacements will necessitate investments amounting to billions of euros. Moreover, this task carries a...

Characterization of undrained shear strength in Dutch sites using Hierarchical Bayesian Modelling

This thesis discusses the characterization of the undrained shear strength, S_u from the net cone resistance, q_net of clay in Dutch sites using Hierarchical Bayesian Modelling (HBM). The performance of the HBM is compared with the current practice methods of the site characterization which propose either the use of only site–specific...

Schematization of shear strength: The influence of the schematization of the shear strength on the macro-stability safety assessment

The Water Authority Rivierenland is responsible for periodically assessing the safety of the dike trajectories in the Alblasserwaard region. In 2012, the safety assessment for inner slope macro-stability was performed based on stress dependent design values for the shear strength, based on the cell test<br/>collection of the Water Authority. The...

Implementation of spatial variability in PLAXIS

As a consequence of the difficulty to obtain complete direct information about the subsurface, and the importance of heterogeneity of soil properties in geotechnical design, a desire exists in the geotechnical community for a smarter use of the available data in common practice. The objective of this thesis is to provide a potential solution for...

Reliability-based updating of anchor capacity

This research focuses on reliability-based, Bayesian updating of grout anchors’ bearing capacity. Firstly, grouted anchors are commonly used in practice, even though large uncertainties surround their bearing capacity. Secondly, every anchor must be tested on their working load for quality assurance. Because of the combination of those two...

Probabilistic classification of soils based on Local Average Subdivision method and CPT data

A random field generator based on Local Average Subdivision (LAS) method is proposed in this study in order to achieve probabilistic soil classification and quantify the uncertainty of the generated most probable geological cross section. CPT data and Robertson’s soil classification chart (1990) are adopted to classify the soil. The sole...

A Reliability-Based Design Optimization Method for Geotechnical Engineering Problem Based On Active-Learning Kriging Metamodeling

Using an expensive-to-evaluate numerical model, such as a finite element method (FEM) model, is deemed unavoidable in solving modern geotechnical engineering problems. At the same time, the application of reliability analysis in dealing with uncertainties (e.g. soil properties) is increasing rapidly. This could pose a time-wise problem for an...

Probabilistic identification of soil stratigraphy using CPT data

The deterministic approach for interpreting CPT soil profiles poses the serious limitation of not taking data uncertainty into account. Therefore, a Bayesian model was developed by Wang et al. (2013) that, for a given CPT profile, determines the most probable number of soil layers and most probable soil layer thicknesses by simulating and...

Reliability Benchmarking of Eurocode 7 Design Examples: CIE5050-09: Additional Thesis Project 2021

The application of reliability analysis in geotechnical engineering is relatively new compared to the other sections of civil engineering such as structural engineering and hydraulic engineering. However, due to its increases use in recent years, reliability analysis is planned to be included extensively in the upcoming Eurocode 7 (EN 1997)....

Reliability Studies of Slope Stability: Effect of various approaches to derive distributions of soil properties in reliability studies of slope stability

In the past few decades, the use of Bayes' theorem in geotechnical engineering has increased significantly. A good amount of work is done on implementing this theorem for improving the knowledge on soil properties, identification of soil strata, and quantifying different uncertainties involved in predicting soil properties. However, the results...

Reliability analysis of quay walls using metamodelling

Reliability analysis is a rational method for dealing with uncertainties. It is increasingly used for the design and assessment of (civil) structures. Reliability analysis, possibly in combination with performance data, allows for instance to update (extend) the lifetime of existing quay wall structures. This gives economic advantages when...

Assessment of macro-instability using SHANSEP in RFEM: The application of SHANSEP in combination with RFEM for safety assessment of dikes.

The Dutch Water board revised their guidelines for the safety assessment of dikes in 2017. A major change for the assessment of macro-stability is the use of the SHANSEP method to estimate the strength of impermeable cohesive layers. The failure probabilities are estimated with a deterministic analysis using limit equilibrium methods. The use of...

Probabilistic analysis of slope stability in spatially variable soils using Monte Carlo simulation

Soil properties are spatially variable due to the natural deposition process. Because of this inherent spatial variability, a slope can actually fail along any potential slip surface. A single value of Factor of safety cannot account for this variation dominated the slope stability problem. Probabilistic analysis considering the spatial...

The effects of anisotropy and heterogeneity in the piping sensitive layer

Levees are earthen structures that are designed to protect land from flooding and are commonly composed of impervious soils and built on sandy foundations. They are sensitive to an erosion process that is known as piping. After several years of investigation into piping, Sellmeijer proposed design rules by curve fitting results of a numerical...

Assessment of the probability distribution of the phreatic surface in a regional flood defence: Finite element computation for a better understanding of the influence of precipitation on the phreatic surface

A large part of the Netherlands consists of polder area. Therefore the inhabitants have to rely on the Dutch flood defence system to protect them against floods. A vast network of drainage canals ensures that the seepage water and the precipitation water is transported from the polders toward the outside water. There are several mechanisms which...