In common practice, quay walls are engineered to fulfil their services for a minimum lifetime. However, in many cases, quay walls are designed stronger than minimally required, which means that the quay wall could be able to serve its purpose over a longer period or endure higher loads. In general, the optimization of quay wall designs or the assessment of the extension load-bearing capabilities, particularly in existing structures, is substantiated through probabilistic design methodologies.

This study investigates the operation of reliability updating with deformation data to enhance the operational lifespan and load-bearing capacity of existing quay walls. Traditionally, quay walls are designed with predetermined probabilities of failure based on preliminary information gathered through desk studies and on-site investigations. Observations of existing structures provide new information on the actual deformation behaviour. This study acknowledges the conservative assumptions in initial designs, potentially resulting in concealed geotechnical and structural capacities. It introduces a novel approach involving reliability updating using monitoring data from 'smart' quay walls equipped with advanced sensors. These sensors, measuring especially lateral deformations, provide input for the updating process in a Bayesian model.

Application of this methodology is demonstrated through a theoretical and an actual case study, including the Sif quay wall in the Port of Rotterdam (Maasvlakte II).

The theoretical case study validated the methodology. This was done by updating two initial (prior) distributions for the friction angles of two soil layers using the observed maximum deformation for a combination of predefined values of the friction angles. The updated (posterior) distributions converged towards the predefined values and the distributions reduced in variation or became more informed. These findings affirmed the overall operation of the intended method and proved the efficiency and accuracy of the addition of metamodelling. However, the success of the metamodel appeared to strongly rely on appropriate settings for the specific situation.

For the case study of the Sif quay wall, its deformation behaviour was analysed for three different load cases accounting for the effect of excavation, the effect of water level fluctuations and the effect of top loading. The most recent deformation measurements, together with the knowledge of past deformation behaviour, have proved most useful for updating as all aspects contributing to the lateral deformation of the quay were present. In the updating process of the Sif quay wall case study, six stochastic variables were analysed: the strength (friction angles) and stiffness parameters (stiffness moduli) of three influential soil layers. Within the scope of this study, an increase in one or both parameter types means that the structure may have a higher functional capacity than expected, in the form of moment or normal force capacity.

Here, the strength parameters proved more prone to updating than the stiffness parameters and showed a significant increment. The initial parameter uncertainty indicated by the standard deviation was found to have minimal impact, but larger discrepancies between predicted and observed deformations led to more significant updates.
The quay wall at the Sif terminal appeared to have a negligibly small failure probability, even before updating. Therefore, the impact of updating was not measurable in terms of the reliability index, but the outcomes of the limit state function distribution were significantly impacted: their variation was reduced, and the overall distribution moved away from the point of failure.

Regarding cost-effectiveness, the risk mitigation for existing walls after monitoring and reliability updating might be limited. However, the potential for significant steel reduction in new quay wall designs based on updated soil information highlights the value of reliability updating. The approach of this study may lead to more efficient and sustainable quay wall construction practices.

The study also acknowledges limitations in the simplification of the soil model compared to the actual situation and the consideration of one single failure mechanism. Another important factor is the limited level of knowledge on the quay wall deformation conditions, such as loading magnitudes and potential time-dependent effects, compared to the minimized model uncertainties. This aspect should be taken into account when evaluating the results of the update results. Recommendations for further research include:
• To achieve a more realistic representation of quay wall behaviour, it is recommended to incorporate various failure mechanisms, including geotechnical failure, as real-world failures often involve the interplay of multiple mechanisms.
• For a more robust prediction, the model should explore a wider range of stochastic variables, including factors like bed level, water level fluctuations, and top load.
• To enhance the accuracy of the updated parameters, it is recommended to acquire additional measurement data through on-site loading tests or by implementing smart bollards for real-time loading information.
• Investigating the correlation between the stochastic variables is crucial for understanding their combined influence on the model's predictions. This analysis will lead to more accurate results.
• To maximize its practical value, the model should be extended for applications such as berth deepening or designing for increased top loads.

In summary, this research highlights the potential of reliability updating with deformation data, offering more insights into a possible increase of a quay wall's capacity. By understanding a quay wall's reliability, port authorities can optimize its use and extend its service life, reducing environmental impact and bringing economic benefits.

Port of Rotterdam has the ambition to reduce the footprint for building new quay walls, this is in line with their ambition to reduce the footprint and with national goals to limit global warming. The aim is to use less materials and/or use different design solutions. These reinforced structures are designed in a conventional way and the internal forces are determined by performing a Linear Elastic Analysis. The reinforcement is calculated using the internal forces and is based on the Eurocode 1992 -1-1. The conventional approach includes various assumptions that affect the amount of concrete and steel used, which influences the CO2 footprint, structure reliability, and costs. In order to know the effects of these assumptions, advanced nonlinear calculations are carried out using volume elements

Marine structures are frequently equipped with rubber fender systems, which absorb the berthing en­ergy in order to protect both the marine structure and the berthing vessel. These fender systems absorb the kinetic berthing energy by elastic deflection and the associated reaction fender force introduces a berthing impact load acting on the vessel’s side hull. In guidelines and rules on ship design, recommendations regarding the structural resistance due to external fenders are not present. On the other hand, special requirements state minimal strengthening for tug resistance, which results in marked areas on a vessel’s side hull at which tug contact is allowed. Also for ships equipped with integrated steel fenders in their side hull, also known as beltings, minimal strengthening is required. Since the use of fender systems in ports is common, and all ships require to berth in a port the maximum hull loading due to fender contact is an important factor to take into account from the vessel’s perspective. PIANC WG33 published design recommendations for the maximum allowable hull pressure in kN/m2 for different types of vessels. The size of the fender contact area is in practice determined by dividing the design reaction force by the maximum allowable hull pressure. However, the hull pres­sures in this recommendation are based on the pressure on the keel of a fully laden vessel. Based on this background information, not all values are reliable, since some pressures correspond to a draft of 70 meters. Besides that, the pressure formulation does not contain information on the specific geom­etry of the contact area, i.e. height and width. This thesis systematically analyses the strength of the vessels’ parallel side hull for different failure modes, e.g. yielding in the stiffeners due to excessive bending­ or shear stresses. The structural ge­ometry of various vessel types is represented by various grillages. Two different pressure distributions were considered: a soft contact area, and a rigid contact area, to cover the most extreme behaviour of a fender panel. The results of this study show that the allowable load is largely influenced by the geometry of the contact area. The fender panels designed using the PIANC WG33 fender design are not always opti­mal. Especially for fender panels having large widths, the current guidelines seem to be too optimistic. Consequently, it is necessary to define a maximum width to what extent the current guidelines are allowable. This study shows that a specific allowable force in kN for a specific geometry is preferred over the current guidelines. In this study, a general formulation for the maximum allowable hull loading is proposed. This for­mulation requires the specific structural lay­out of the vessel that encounters the berthing facility. If the specific ship’s particulars are not known, recommendations are provided for different vessel types. These recommendations consist of a new acceptance criterion for each vessel type, which can be used to optimise the geometry of fender panels. The findings of this study can be used in the design of fender systems and the new design criterion has been submitted to the members of PIANC WG211.

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 assessing quay walls, figuring there are thousands of kilometres of quay walls worldwide. Soil-structure analysis (e.g. analysis of quay walls) is however complex and in general requires finite element (FE) models. Conventional reliability methods are mostly incapable of dealing with FE models because they have long (infeasible) calculation times e.g. Monte Carlo, or they cannot deal with the typical noisy and incomplete FE model output e.g. FORM. One way of dealing with these challenges is by using a metamodelling approach, i.e. build up and make use of a response surface on a limited number of model evaluations. One specific application which uses metamodelling is ERRAGA, which is an abbreviation for Efficient and Robust Reliability Analysis for Geotechnical Applications. This thesis investigates the potential of ERRAGA/metamodelling for reliability analysis of quay walls in engineering practice.\medskip

In this thesis ERRAGA is tested on two realistic case studies located in the port of Rotterdam. The first case is called the ‘Sleepbootkade’, a quay constructed from a combi wall with anchors. The second case study is called the HHTP-quay, a combi wall with relieving platform and MV-piles. In the first case focus is placed on getting to understand the details and workings of the ERRAGA method. In the second case focus has been put on the creation of the reliability model and the practical applicability of ERRAGA using the experiences of the first case. Two critical limit states are tested within the case studies: wall failure in bending and geotechnical failure. Especially the limit state geotechnical failure is challenging as relevant output parameters are known to be noisy and/or incomplete.\medskip

The main finding of this thesis is that reliability analysis of quay walls using ERRAGA in combination with a numerical model shows good potential. ERRAGA can generate reliable and accurate results within only hundreds of realizations, hereby overcoming the main drawbacks of existing reliability methods. Main drawback of the ERRAGA method seems to be its inherent complexity and ‘black box’ nature. For the user to employ the full potential of the method some more in depth knowledge and especially the user-defined settings are required. Based on the gained experiences in this thesis some first recommendations are presented for the use and application of ERRAGA in projects.