Maritime ports are key components of global logistics networks, with steel quay walls providing berthing capacity and operational continuity. Their long-term structural performance is governed by corrosion driven by interactions between salinity, hydrodynamics, microbiological activity, and climatic conditions. Given that across Europe, many twentieth-century structures have exceeded their design life, reassessment of safety and residual capacity is essential. Conventional assessments typically use deterministic, uniform corrosion profiles based on simplified environmental classifications. In practice, however, field data show that corrosion is spatially variable, has short correlation lengths, and involves co-existing uniform and localised mechanisms. The scarcity of long-term, spatially detailed measurements has limited of site-specific deterioration models to be validated and included in design codes. This study analyses corrosion in steel quay walls at the Port of Rotterdam using ultrasonic thickness measurements and laboratory surface-morphology data. The database quantifies mean wall-thickness loss and spatial variability, enabling systematic comparison with design prescriptions. To interpret the observed variability, the study develops a stochastic corrosion representation based on random-fields, allowing explicit incorporation of spatial heterogeneity into structural assessments. The outcomes highlight the limitations of uniform corrosion assumptions and provide a basis for improved reliability evaluations and lifecycle-management strategies for ageing port infrastructure.

Ground anchors are crucial components in various construction and engineering applications. They play a critical role in retaining structures and, therefore, design guidelines have established the necessity of comprehensive testing campaigns to derive the anchors characteristic resistance. The latter is a specified percentile within a presumed statistical distribution. In principle, a limited number of investigation tests cannot be used to estimate the characteristic values. To overcome this limitation, in a simplified way, the design codes suggest reducing the resistance found in experimental results by a factor to estimate the anchor characteristic resistance to be used in the design. In this paper, the authors propose a new approach for interpreting ground anchor test results and determining the statistical distribution of ground anchor resistance. The approach is based on the use of Bayesian updating, formulated as a structural reliability problem, and on the definition of a simplified phenomenological model relating the imposed load and the measured anchor (creep) displacements. This distribution can be used to determine a “proven” anchor characteristic resistance, which can then be used to update the anchor design.

Propellers of ships generate high velocities adjacent to quay walls, jetties and locks. Generally, a bottom protection is installed in order to prevent instability due to scour. Although design guidance exist, propeller-induced loads are far from fully understood and have predominantly been derived on the basis of model tests. The validation of the existing design methods is lacking, especially for specific types of bow thrusters. In this research, field measurements of flow velocities induced by a 4-channel bow thruster system against a vertical quay wall have been performed. Test results showed a flow characterized by low mean velocities and large fluctuations, with the extent of reflected flow limited to few meters from the quay wall and inflow beneath the suction points playing a role.

With the preparation and development of PIANC WG 211, it is evident that clear design recommendations for vessel berthing velocities need to be derived, since this is one of the most critical parameters in fender-system design. This paper discusses recommendations on how to determine the characteristic berthing velocities for the design of fenders systems, with and without the use of field observations. Furthermore, the proposed characteristic berthing velocities have been compared with the guidelines of PIANC WG 33, PIANC WG 145, the German EAU 2012, and the Spanish ROM. Based on the findings of these investigations, some historically embedded hypotheses will need to be reconsidered. The key findings of this study are considered useful for the design of fender systems for new berthing facilities and for the assessment of existing marine structures.

Design of fender systems consists of two distinct steps: selection of an appropriate fender based on berthing energy demands from the berthing vessel and design of the supporting structure based on the reaction force imposed by the fender on the structure. Both steps include load or safety factors to increase the level of safety. The factor applied to the selection of fenders has up until now been referred to as an "abnormal berthing factor," with relatively vague recommendations for suggested values for use, usually between 1.25 and 2.0. British Standards (BS 6349-4:2014) has recently chosen to refer to this value as an "energy factor" instead of the previously used abnormal berthing factor. Codes and standards for design of most structures are often based on methods involving what is often referred to as load factors, partial load factors, or resistance factors. As an example, Load and Resistance Factor Design (LRFD) in the US applies load factors to the different loads acting on a structure, and resistance factors to the capacities provided by the structural elements. Similarly, the Eurocode, OCDI, and British Standards use the partial factor method where the effect of the characteristic action, which can be a specified load or imposed deflection, multiplied by the load factor must not exceed the design resistance, i.e., characteristic resistance divided by the partial factors for materials. Although their applications are seemingly simple, these methodologies are based on substantial statistical work, including extensive collection of statistical data, a careful analysis of the data, and appropriate selections of safety levels and acceptable probabilities of failure. This paper explores how utilizing statistical data from berthing velocities, fender manufacturer data, and other adjustment factors were used to establish suggested partial energy factors for selection of fenders. This is what previously has been described as the abnormal berthing factor. By utilizing this method, energy factors can be recommended based on several factors, such as anticipated vessel traffic, type of terminal, type of fender system, or whether the analysis is done for new or existing structures. The suggested factors will provide much clearer guidance than what is currently given in the current fender design guidelines from PIANC WG33 and will be the basis for recommendations on energy factors in the upcoming document from WG211.

The assessment of service-proven quay walls subject to corrosion-induced degradation is inherently a time-dependent reliability problem. Two major challenges are the modelling of corrosion and taking into account the decrease of epistemic uncertainty throughout the quay wall's service life. The main objective of this study is to examine the probability of failure, despite successful past performance, when the quay wall is subject to corrosion and randomly imposed variable loads. The development of the annual failure rate is modelled using crude Monte Carlo and by performing a first-order system reliability analysis. The annual failure rates found for service-proven quay walls vary over time. For those with successful service histories and subject to low corrosion rates, the highest reliability indices are observed in the first year of the service life, whereas with higher corrosion rates the final year prevails. In general, it seems more practical to evaluate reliability on an annual basis rather than over longer time periods, since the latter will introduce an iterative procedure to determine the wall's remaining lifetime. The key findings of this study can be crucial for the lifetime extension of existing quay walls, and presumably also for other service-proven geotechnical structures subject to corrosion.

While reliability methods have already been widely adopted in civil engineering, the efficiency and robustness of finite element-based reliability assessments of quay walls are still fairly low. In this paper, the reliability indices of structural and geotechnical failure modes of two real-life quay walls are determined by coupling probabilistic methods with finite element models, taking into account a large number of stochastic variables. The reliability indices found are within the range of the targets suggested in the design codes presently in use. Nevertheless, neglecting model uncertainty and correlations between stochastic variables leads to an underestimation of the probability of failure. In addition, low sensitivity factors are found for time-independent variables, such as material properties and model uncertainty. Furthermore, the results are used to reflect on the partial factors used in the original design. Important variables, such as the angle of internal friction, are subjected to a sensitivity analysis in order to illuminate their influence on the reliability index. Port authorities and terminal operators might be able to use the findings of this paper to derive more insight into the reliability of their structures and to optimise their service life and functionality, for example by deepening berths or increasing operational loads.

This paper present several cases in the Port of Rotterdam where both in the design and construction phase several different did not marched as expected. These cases are interesting for both the design as well the construction phase of a project. People will make mistakes however the mistakes describes in this paper have to be judged in time as not always everything was understood during the design and construction and the people of that time still these huge structures.

Structures, such as quay walls, have to meet a particular level of safety. Consequently, in the Eurocode standards, three reliability classes are distinguished, each corresponding to a target reliability index and set of partial factors. In this study, more insight is acquired into the relationship between the quay wall's construction costs and the associated reliability index β. It appeared that the marginal costs of safety investments of quay walls are fairly low and in the same order of magnitude of the uncertainty of the estimate of the construction costs. Hence, it seems that the current reliability classes, as defined in the Eurocode standards, are non-efficient for quay walls. In addition, this study investigates the influence of the partial factors and three failure mechanisms on the construction costs and the reliability index. It was concluded that for the considered cases, the soil's angle of internal friction strongly influences the construction costs and the β of the quay wall. Furthermore, it follows that economic optimisation in the probabilistic design of quay walls is possible by increasing the target reliability index of the failure mechanism 'insufficient passive soil resistance' and decrease the target reliability index of 'yielding of sheet pile profile'.

General frameworks for reliability differentiation have evolved over time and are mainly developed for buildings. However, recommendations for the safety of existing quay walls are lacking. In this study, target reliability indices for assessing existing quay walls were derived by economic optimisation and by evaluating the requirements concerning human safety. In quay-wall design, some dominant stochastic design variables are largely time-independent, such as soil and material properties. The influence of time-independent variables on the evolution of the probability of failure was taken into consideration, since this affects the present value of future failure costs and the associated target reliability indices. The target reliability indices obtained for existing quay walls depend on the consequences of failure and the remaining lifetime. If the failure modes of a quay wall are governed by time-independent design parameters and the quay wall has already survived the early service period, the residual probability of failure is lower for an existing quay wall compared to a new structure. Hence, this should be considered in the determination of target reliability indices. The method to evaluate quay-wall reliability over time can also be used to assess other civil and geotechnical structures.

General frameworks for reliability differentiation have evolved over time and are mainly developed for new buildings. However, recommendations for existing quay walls are lacking. In this study target reliability indices for assessing existing quay walls were derived by economic optimisation and by evaluating the Life Quality Index criterion (LQI). In quay wall design, some dominant stochastic design variables are largely time-independent, such as soil and material properties. The influence of time-independent variables on the development of the probability of failure was taken into consideration in this study, because this affects the present value of future failure costs and the associated target reliability indices. The reliability indices obtained in accordance with the LQI acceptance criterion were a little lower than the target reliability indices derived by economic optimization. The target reliability indices obtained for existing quay walls depend on the consequences of failure and the remaining service life. If failure modes of a quay wall are largely time-invariant and already survived the first period of the service life, the residual probability of failure is lower for an existing quay wall compared to a new quay wall. Hence, this should be considered in the determination of target reliability indices. The method of approach to assess the development of reliability over time can also be used for evaluating target reliability indices of other civil and geotechnical structures.