This paper describes the effects of uncertainty inherent to the choice of hydraulic load and soil parameters on the geotechnical revetment design. As for the practitioner, the effect of uncertainties on the required armour layer thickness is studied. Uncertainties inherent to revetment design mainly result from the load and resistance parameters employed in the design. At present, design loads are obtained from empirical equations and worst-case 'design vessel passages'. Characteristic soil parameters are defined on the basis of a limited number of field and laboratory tests. Thus, uncertainties arise with regard to the choice of characteristic values. In order to investigate the effects of parameter uncertainty on the revetment design, distributions and correlations of loads are assessed using vessel passages observed in the field. In ensuing uncertainty analyses it is found that at present available data does not allow approximating loads by means of probability functions, whereas for the soil parameters the results indicate that the minima of the soil parameters govern the design. However, it is also found that when considering more than one soil parameter as random variable, a less conservative design can be achieved as with the individual minima. As a conclusion, recommendations regarding parameter choice and design procedure are provided.

The German Federal Waterways and Shipping Administration (WSV) maintains about 7235 km of waterways whose shores are mainly secured by loose or grouted armor stones. To enable the WSV to make optimal use of its resources, taking into account boundary conditions such as economic efficiency and nature protection requirements, an extension of the current German design concept towards maintenance is required. In this paper a "classical" reliability analysis is conducted to investigate the probability of armor stone displacements along German inland waterways. Subsequently, it is proposed to use the obtained probabilities of armor stone displacement in Markov chain simulations to relate the former to the number of ship passages and time. Eventually, this may allow estimating maintenance intervals in regard to actual traffic density. The methodology is illustrated with traffic observations along four artificial inland waterways in Germany. The results are discussed in relation to the consequences for embankment maintenance and applicability in practice.

This article presents an interdisciplinary methodology that provides decision makers with key figures on the reliability of ageing structures in transport infrastructures. The methodology is closely connected to ongoing discussions about proactive and sustainable maintenance strategies under increasing economic and ecological pressures. Since the infrastructures of the main modes of transport in Germany, that is, roads, railways and waterways, pose similar challenges to the responsible governmental authorities and administrations, the development of the methodology presented in this article is embedded in the research programme 'BMVI Network of Experts'. Under the premises of the research programme, the methodology provides a step-by-step approach to creating a profound knowledge base which is required for the reliability assessment of ageing infrastructures. The methodology aims at generating meaningful key figures about the structural condition of an assessed asset for a risk-informed maintenance strategy. The examples of a condition assessment procedure based on a fuzzy criticality recommendation and a screening tool for ranking a large number of structures using operative reliability indices illustrate how the interdisciplinary methodology allows the development of user-friendly tools to support and facilitate the management of infrastructure maintenance in the responsible governmental entities.

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Der zukünftige Eurocode 7 wird ausdrücklich die Nutzung zuverlässigkeitsbasierter Methoden in der geotechnischen Planung und Bemessung erlauben. In Deutschland gibt es bisher kaum Erfahrung in der praktischen Anwendung derartiger Verfahren und entsprechend sind die Vorbehalte gegenüber diesen Methoden oft groß. Der neue DGGT‐Arbeitskreis (AK) 2.15 „Zuverlässigkeitsbasierte Methoden in der Geotechnik“ hat sich zum Ziel gesetzt, durch praxisorientierte Anleitungen und Empfehlungen sowie begleitende Aus‐ und Weiterbildungsangebote den praktischen Zugang zu diesen Verfahren zu unterstützen. Ziel ist es, Möglichkeiten und Grenzen zu verdeutlichen sowie vor allem ihre Potenziale zu erschließen. In dem vorliegenden Beitrag werden allgemeine Grundlagen und die zukünftigen Arbeitsfelder des AK 2.15 vorgestellt. Ausgehend von der Einführung relevanter Fachbegriffe wird zunächst die Einbettung zuverlässigkeitsbasierter Verfahren in den aktuellen Normungs‐ und Regelungskontext aufgezeigt. Anschließend werden anhand des Lebenszyklus eines geotechnischen Bauwerks die Unsicherheiten in den geotechnischen Prognosen und Bewertungen beschrieben. Daran anknüpfend wird aufgezeigt, an welchen Stellen zuverlässigkeitsbasierte Methoden als mögliches Werkzeug sinnvoll genutzt werden können, um Ingenieur:innen, Bauherr:innen und Prüfer:innen in Nachweis‐ und Entscheidungsprozessen zu unterstützen. Zu den sich daraus ableitenden Arbeitsthemen werden durch den AK 2.15 zukünftig Empfehlungen erarbeitet und sukzessive veröffentlicht.