Reliability updating for lateral failure of historic quay walls

The historic canal walls of Amsterdam, stretching 200 km in total, are constructed as a masonry wall on a timber deck supported by vertical timber piles. Understanding the resistance against lateral failure of these quays has been challenging due to uncertainties in their working principles, geometry, soil and structural properties. This...

Calibration of Partial Factors for Basal Reinforced Piled Embankments

In the Netherlands, the design guideline for basal reinforced piled embankments has been revised (CUR226:2015) adopting a new analytical design model (The Concentric Arches (CA) model, Van Eekelen et al., 2013; 2015). The CA model provides geosynthetic reinforcement (GR) strains which were compared with laboratory and in situ measurements (Van...

Developments in Levee Reliability and Flood Risk Analysis in the Netherlands

This paper presents and overview of advances in flood risk and levee reliability analysis in the Netherlands. It is described how new safety standards – in the form of a target failure probability – have been derived on the basis of nationwide flood risk assessments which taken into account both economic risk and risk to life. The process for...

Value of information in retrofitting of flood defenses

Dikes and levees play a crucial role in flood protection. The main causes of levee failures are of geotechnical nature; geotechnical failure modes are also the main contributors to the probability of failure of flood defences due to the typically large uncertainties in ground conditions. Hence, information on ground conditions and soil...

Flood risk and economically optimal safety targets for coastal flood defense systems

A front defense can improve the reliability of a rear defense in a coastal flood defense system. The influence of this interdependency on the accompanying economically optimal safety targets of both front and rear defense is investigated. The results preliminary suggest that the optimal safety level of a coastal flood defense system can only be...

Briefing: Lessons learned from failures of flood defences

Failure of flood defences during extreme events can lead to enormous damage and loss of life. This paper presents lessons learned from investigations of flood events over recent years, including the 2005 flooding in New Orleans, USA, caused by hurricane Katrina. Based on these findings, new developments in the field of research, design and...

Value of information in levee monitoring and inspection (poster)

Probabilistic design of relief wells systems as piping mitigation measure

Nowadays there is an on-going discussion about piping safety for dikes in the Netherlands. Relief wells represent an attractive solution as mitigation measure against piping, saving hinterland space. Nevertheless, they have been disregarded due to the uncertainties in its performance over its life cycle. The aim of this contribution is to...

On reducing piping uncertainties: A Bayesian decision approach

Dikes and levees play a crucial role in flood protection in deltaic areas such as the Netherlands. Internal erosion piping or under-seepage is a major cause of levee failures and a main contributor to the probability of failure of river levees due to the large (mostly geotechnical) uncertainties. The present thesis investigates how geotechnical...

Floods in Germany

Re-assessing reliability based on survived loads

The reliability of flood defenses is often dictated by large uncertainties in the hydraulic loading and the structural resistance. Additional information decreases uncertainty, however, acquiring it is often costly. One source of information, even though in many cases readily available, is hardly used – survived loads. This article shows how...

Safety standards of flood defenses

Current design codes like the Eurocode use safety or reliability classes to assign target reliabilities to different types of structures or structural members according to the potential consequences of failure. That, in essence, is a risk-based criterion. A wide range of structures is designed with such codes, and distinction is made between...

Calibration of piping assessment models in the Netherlands

New insights into the failure mechanism piping (under-seepage) regarding the physical process as well as reliability aspects have led to a revision of the Dutch design and safety assessment rules for dikes. This paper describes how the required factor of safety for piping is derived from a top level requirements formulated in terms of an...

A Factor of Safety for Geotechnical Characterization

Updating piping probabilities with survived historical loads

Piping, also called under-seepage, is an internal erosion mechanism, which can cause the failure of dikes or other flood defence structures. The uncertainty in the resistance of a flood defence against piping is usually large, causing high probabilities of failure for this mechanism. A considerable part of this uncertainty is of epistemic nature...

Reliability analysis of a hydraulic fill with respect to liquefaction and breaching

A recently reclaimed site in the Port of Rotterdam will serve as location and foundation of an LNG terminal. LNG (Liquefied Natural Gas) is recognized as hazardous material and underlies strict safety requirements. As part of the safety assessment of the entire installation, a specific analysis had to be carried out concerning the geotechnical...

River System Behaviour Effects on Flood Risk

A risk-based safety approach is indispensable to support decision-making on flood protection strategies and measures. Hitherto the effects of river system behaviour on flood risk have usually been neglected. River system behaviour refers to the fact that the flood risk (or safety) of a particular area may depend on the safety of other adjoining...

Reliability of Sheet Pile Walls And The Influence of Corrosion: Structural Reliability Analysis with Finite Elements

The Finite Element Method is well accepted in design practice nowadays. It can be used for modeling complex structures and systems. The constitutive models are improving, which enables us to make more accurate predictions of the real world behavior. On the other hand, especially in the field of geotechnical engineering, the uncertainties in the...