Quay Wall Research Articles

Development of AI-Based Multisensory System for Monitoring Quay Wall Events

Development of AI-Based Multisensory System for Monitoring Quay Wall Events

Numerical analysis of the effect of vibroflotation in the vicinity of a deep-water quay wall

The paper describes an attempt to include the effect of vibroflotation on the quay wall in the numerical analysis. An axisymmetric FEM model was made, in which the increment of pressure on the steel wall, caused by initiated horizontal displacement, was checked. The stress read off in this way has been implemented in the plane strain model of the quay wall. The results of the internal forces and deformations are presented. The displacements were collated with the geodetic survey

Assessment of Load Test Results on a Sheet Pile Quay Wall: The Potential of 3D Numerical Modeling

Assessment of Load Test Results on a Sheet Pile Quay Wall: The Potential of 3D Numerical Modeling

Innovative application of micro-drilling for the assessment of decay and remaining mechanical properties of historic wooden foundation piles in Amsterdam

The majority of bridges and quay walls in the centre of Amsterdam are supported by 100–300 years-old wooden foundation piles subjected to bacterial decay. Bacterial degradation proceeds at a slow rate, allowing the piles to perform their function for many years, although causing a reduction of their load-carrying capacity over time. In this study, micro-drilling measurements were employed to capture the amount of decay and remaining short-term compressive strength of the historic wooden piles. The applicability of micro-drilling was studied on 60 wooden piles with various decay levels, retrieved after 100–295 years of service life. An algorithm was developed for analysing the micro-drilling signals, aimed at determining the decayed outer layer of the piles’ cross section, and validated with the results of mechanical testing on the piles. The micro-drilling technique is now used on a large scale in Amsterdam, supporting the assessment of the wooden foundation piles in the city.

MT-InSAR Optimisation for Structural Health Monitoring

The implementation of effective and sustainable Structural Health Monitoring (SHM) systems for the evaluation of infrastructure conditions is critical to address the deterioration and damage experienced by structures worldwide. Given the vast number of structures involved, resorting to traditional in-situ visual inspections and data gathering methods is becoming increasingly unfeasible. Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) has recently gained attention as a viable solution for long-term SHM. This remote sensing technique combines multiple satellite radar images to measure changes in the Earth’s surface over time. Unlike conventional techniques, MT-InSAR does not require in-situ installations and offers extensive coverage, enabling observations across diverse location and structures. However, the applicability of MT-InSAR monitoring depends on the relatively unpredictable distribution and location of permanent scatterers (PSs), which are influenced by surface characteristics and vegetation changes. Evaluating the reliability and capacity of MT-InSAR is therefore crucial to enhance its effectiveness in assessing the location and extent of structural damage. In this study, we present an effective approach to determine the optimal number and position of PSs for detecting different structural damage mechanisms. The approach is exemplified through a case study of a quay wall in Amsterdam, with data inputs simulated using the Finite Element Method. The proposed method has the potential to evaluate the feasibility of MT-InSAR for a broader range of scenarios, enabling to detect specific structural conditions.

Evaluating the Geoengineering Performance of a Gravity Multiblock Quay Wall and Jet-Grouting on Marine Clayey Soils along the Korean Coastline

Evaluating the Geoengineering Performance of a Gravity Multiblock Quay Wall and Jet-Grouting on Marine Clayey Soils along the Korean Coastline

Disentangled representation learning with physics-informed variational autoencoder for structural health monitoring

The maintenance and replacement of aging infrastructure is becoming increasingly costly, as a large number of structures is approaching the end of its design lifetime. Labor intensive manual inspection and assessment on a large scale is often infeasible, while data-driven machine learning techniques can fail to identify relevant failure mechanisms and suffer from poor generalization to previously unseen conditions, particularly when data is sparse. We propose a multi-task learning approach based on a physics-informed variational autoencoder that leverages a dictionary of physics-based models to improve the predictive performance when limited data is available. The latent space of the autoencoder is augmented with a set of physics-based latent variables that are interpretable and allow for prior knowledge on the latent variables to be included in the autoencoder formulation. To prevent the data-driven components of the encoder and decoder from overriding the known physics, a regularization method is used to impose physical constraints on the latent space and the generative model prediction. The feasibility of the proposed approach is evaluated on a case study of quay walls in Amsterdam, demonstrating improved performance over purely data-driven methods.

The application of flexible and porous concrete structures in training works and scour protection

Concrete armour units such as Xbloc have been applied as armour layer for breakwaters and bank protections for years. These smartly shaped blocks were invented to offer efficient protection at more exposed locations by applying blocks that work together with neighbouring units to withstand high wave loads (Interlocking). Also material use was lowered since steeper slopes could be realized compared to conventional rock structures. Xstream and Xstone can be applied in a large range of applications that are traditionally built with loose rock, pitched rock or smooth block revetments such as: - Bed protection (e.g. offshore wind foundations) - River training works - Detached breakwaters - Quay wall protection in harbours - Revetment structures This abstract elaborates on why flexible and porous structures made of these small-scale [0.2 – 0.6m] concrete armour units are an interesting, low CO2 and eco-friendly alternative for bed protections and river training works.

Decay Of Bow Thruster Induced Near-Bed Flow Velocities At A Vertical Quay Wall: A Field Measurement

During berthing operations vessels use bow thruster(s) to improve their manoeuvrability, making them less dependent on the assistance of tugboats. While manoeuvring, the transversal bow thruster jet can reflect on the quay wall and partially be directed towards the bed. At the intersection between the quay wall and the bed, the jet reflects again leading to a highly turbulent and complex flow field (Figure 1). When the bed is left unprotected scour may occur, which can eventually lead to instability of the quay wall (Roubos et al., 2014). Over the years, the shipping industry has been developing continuously, characterized primarily by the upscaling in size of inland- and sea-going vessels (OECD, 2015; Weenen et al., 2020; Looye, 2021). As a result, vessels have larger draughts, more power and larger thruster diameters leading to higher hydraulic loads on quay walls and bed protections of berthing facilities (Roubos & Verhagen, 2007). To complicate the matter even more, the jet from a transversal bow thruster is confined by the hull of the vessel, the quay wall and the bed. Leading to a complex flow field of the reflected jet and an unknown decay in near-bed flow velocities. Resulting in uncertainties in the design of bed protections, especially in the required width.

Physical Modelling Of Propeller Jet Induced Scour Near Quay Walls

Ship propellers cause high flow velocities near quay walls, jetties, locks and other hydraulic structures which can lead to scour of the bed near these structures and potentially result in instabilities of the construction. Bed protection is commonly applied as a measure to prevent damage and increase the life span of such hydraulic structures. When designing bed protection, the existing guidelines e.g. (PIANC 2015, BAW 2010) may not always result in optimal designs due to simplifications made in jet-flow schematizations and uncertainty of propeller-induced loads. To improve these design guidelines and optimize bed protection, a working group led by CROW and the Dutch Government was formed, and a joint research programme was initiated aiming at developing knowledge on propeller jet-induced scour by combining field measurements (Tukker 2021), scale model tests (Deltares 2023), and numerical modelling. The objective of the presentation during the Coastlab24 conference is to provide an overview of the various measurement techniques applied in the present research.

Analysis of Covered Pile on Multi-row Pile Quay

The multi-row pile quay wall is an innovative permanent structure comprising multiple piles, relieving slabs, flood control walls, and backfill sand. Although it additionally serves as a functional wharf, the research on multi-row pile quay walls remains insufficient. Considering the Changxing harbor Pool as a case study, this research develops a multi-row pile quay wall structure using the three-dimensional finite element software PLAXIS 3D. We investigated the effects of covered piles, pile row spacing, spacing between covered piles, and the stiffness of the front pile on the internal force and deformation of the structure. The findings indicated that the presence of the covered piles results in minimal overall displacement of the multi-row pile quay wall and reduces the bending moment in the front pile. Considering the site conditions and project costs, the sensitivity of different parameters to the retaining effect was evaluated in the order of the stiffness of the front pile > pile row spacing > spacing between the covered piles. Building on this, an optimized design scheme is proposed to reduce the bending moment in the front pile by 50% compared to the original scheme, thereby offering valuable insights for future engineering projects.

New Inscriptions from Aizanoi

New Inscriptions from Aizanoi

Near real-time nautical depth mapping via horizontal optical fibers and distributed acoustic sensing

Safe navigation in ports and waterways subjected to siltation requires nautical depth monitoring. For this purpose, surveying vessels equipped with a zero-offset echo sounder and intrusive point measurements are frequently used. Because these measurements depend on the availability of a surveying vessel and require access to quay walls, such as at the container terminals in seaports, the temporal resolution is limited. Especially at these locations, a high temporal resolution monitoring system could allow for a higher occupancy rate. We propose to use Distributed Acoustic Sensing to monitor the nautical depth using fiber-optical cables. We install five horizontal fibers at different heights between two points and continuously record along the complete installation. Analysing the continuous recordings, we show that horizontal fibers can be used to monitor the water-mud interface depth with a vertical resolution around six mm. Multiple passive sources, like vessel movements and water currents, are used to estimate the water-mud interface.

Large post-liquefaction deformation of sand: Mechanisms and modeling considering water absorption in shearing and seismic wave conditions

Large deformation of sand due to soil liquefaction is a major cause for seismic damage. In this study, the mechanisms and modeling of large post-liquefaction deformation of sand considering the significant influence of water absorption in shearing and seismic wave conditions. Assessment of case histories from past earthquakes and review of existing studies highlight the importance of the two factors. Based on the micro and macro scale mechanisms for post-liquefaction shear deformation, the mechanism for water absorption in shearing after initial liquefaction is revealed. This is aided by novel designed constant water-absorption-rate shear tests. Water absorption in shearing can be classified into three types, including partial water absorption, complete water absorption, and compulsory water absorption. Under the influence of water absorption in shearing, even a strongly dilative sand under naturally drained conditions could experience instability and large shear deformation. The mechanism for amplification of post-liquefaction deformation under surface wave load is also explained via element tests and theoretical analysis. This shows that surface wave–shear wave coupling can induce asymmetrical force and resistance in sand, resulting in asymmetrical accumulation of deformation, which is amplified by liquefaction. A constitutive model, referred to as CycLiq, is formulated to capture the large deformation of sand considering water absorption in shearing and seismic wave conditions, along with its numerical implementation algorithm. The model is comprehensively calibrated based on various types of element tests and validated against centrifuge shaking table tests in the liquefaction experiments and analysis projects (LEAP). The model, along with various numerical analysis methods, is adopted in the successful simulation of water absorption in shearing and Rayleigh wave-shear wave coupling induced large liquefaction deformation. Furthermore, the model is applied to high-performance simulation for large-scale soil-structure interaction in liquefiable ground, including underground structures, dams, quay walls, and offshore wind turbines.

Relationship between peak ground acceleration and damages indices for steel sheet pile quay wall in Bejaia-Algeria

Purpose The purpose of this paper is the dynamic analysis and seismic damage assessment of steel sheet pile quay wall with inelastic behavior underground motions using several accelerograms. Design/methodology/approach Finite element analysis is conducted using the Plaxis 2D software to generate the numerical model of quay wall. The extension of berth 25 at the port of Bejaia, located in northeastern Algeria, represents a case study. Incremental dynamic analyses are carried out to examine variation of the main response parameters under seismic excitations with increasing Peak ground acceleration (PGA) levels. Two global damage indices based on the safety factor and bending moment are introduced to assess the relationship between PGA and the damage levels. Findings The results obtained indicate that the sheet pile quay wall can safely withstand seismic loads up to PGAs of 0.35 g and that above 0.45 g, care should be taken with the risk of reaching the ultimate moment capacity of the steel sheet pile. However, for PGAs greater than 0.5 g, it was clearly demonstrated that the excessive deformations with material are likely to occur in the soil layers and in the structural elements. Originality/value The main contribution of the present work is a new double seismic damage index for a steel sheet pile supported quay wharf. The numerical modeling is first validated in the static case. Then, the results obtained by performing several incremental dynamic analyses are exploited to evaluate the degradation of the soil safety factor and the seismic capacity of the pile sheet wall. Computed values of the proposed damage indices of the considered quay wharf are a practical helping tool for decision-making regarding the seismic safety of the structure.

Sustainable urban logistics: A case study of waterway integration in Amsterdam

This paper tackles the growing challenges in urban logistics by presenting an optimal distribution network that integrates urban waterways and last-mile delivery, tailored for cities boasting extensive waterway networks. We examine Amsterdam's city center as a case study, prompted by the strain on quay walls, congestion, and emissions, urging a reevaluation of its urban logistics design. We formulate the problem as a two-echelon location routing problem with time windows and introduce a hybrid solution approach for effective resolution. Our algorithm consistently outperforms existing methods, with a superior solution quality, demonstrating its effectiveness across established and newly developed benchmark instances. In our case study, we evaluate the benefits of transitioning from a roadway-centric to a waterway-based system, showcasing significant cost savings (approximately 28 %), reductions in vehicle weight (approximately 43 %), and minimized travel distances (approximately 80 %) within the city center. The integration of electric vehicles enhances environmental sustainability, resulting in a total daily emission reduction of 43.46 kg. Our study underscores the untapped potential of inland waterways in easing urban logistics challenges. Inspired by Amsterdam's experience, global cities can adopt innovative approaches for sustainable logistics, providing valuable insights for managers striving to enhance efficiency, cut costs, and promote sustainable transportation practices.

Numerical seismic performance assessment and fragility analysis for gravity-type wharves considering the influence of soil liquefaction

The gravity-type wharf is generally more vulnerable during earthquakes due to its massive gravity quay wall, especially when located in a liquefiable area. Therefore, this study aims to develop numerical analysis procedure for its seismic performance assessment and fragility analysis considering the influence of soil liquefaction. Firstly, the quantitative damage criteria for gravity-type wharves were introduced and verified by case histories. Then, the finite element (FE) modeling of a gravity quay wall founded on liquefiable ground for seismic response analysis using PLAXIS 2D was suggested. Utilizing this modeling, the earthquake-induced damage cases of two gravity-type wharves in two ports in Taiwan were simulated for validation. The seismic performance of both wharves was further assessed by comparing the analyzed response under design earthquake with the damage criteria. Finally, the procedure of seismic fragility analysis based on massive numerical analysis was proposed. Actual earthquake records were scaled to various seismic intensity levels to serve as input motions. Thus, the relationships between the seismic intensity and the damage probability of a gravity-type wharf corresponding to different damage levels, namely, the fragility curves, can be accordingly obtained. These results benefit the seismic performance design and rapid estimation of possible seismic damage of port facilities.

Subgrade Reaction Characteristics to the Anchor Pile of a Sheet Pile Quay Wall

The Conventional Design Method (CDM) for anchored sheet pile quay walls cannot accurately calculate the anchor pile deformation, partly because it does not properly consider the subgrade reaction. This study aims to clarify the subgrade reaction characteristics of the anchor pile using finite element analysis. The CDM assumes that passive failure occurs at the front of the anchor pile. On the contrary, this study shows that the active failure region generated from the back of the sheet pile wall expands to the periphery of the anchor pile and the passive failure region is not generated at its front. Thus, the subgrade reaction to the anchor pile is found to be smaller than the CDM assumption. The CDM also neglects the subgrade reaction in parts shallower than the tie-rod mounting height in the pile front. This study clarifies that the subgrade reaction in this part greatly contributes to the deformation resistance of the pile. Consequently, the subgrade reaction in the shallower range than the tie-rod mounting height is greater than or equal to that in the deeper range. Furthermore, the subgrade reaction has a lower upper limit when acting on the anchor pile than when acting on a horizontally stratified ground, and the difference between these limits widens as the reference earthquake strengthens.

Experimental and numerical studies on behavior of upgraded caisson-type quay wall under earthquake loading

Upgrading the caisson-type quay wall could be conducted by strengthening the rubble mound beneath the front caisson toe. Subsequently, the rubble in front of the wall is removed to increase the front water depth. This study assessed the dynamic response of the upgraded quay wall under earthquake loading and compared it to the existing case using a centrifuge test and numerical study. The tests were performed in a dry condition under six consecutive input waves with increasing magnitude. The results indicated that the upgrade significantly reduced the displacements of the quay wall. The deformation trend of the caisson also changed from overturning to slipping. A numerical study of the upgraded case was conducted using the PLAXIS 2D program in the dry condition to validate the model. In addition, the simulation in water was performed to realize the difference between the models with and without water. The numerical results were in good agreement with the experimental model. The deformed mode of the quay wall in the dry condition did not differ from that in water. However, the horizontal displacement of the quay wall in water was higher than in the dry condition, whereas the vertical component was slightly lower.

Wave motion in a narrow gap coupling with the roll motion of a vessel next to an offshore terminal

Concerning the scenario of a vessel operating alongside an offshore terminal, the vessel being the floating body and the offshore terminal bottom-mounted. The closeness of the two bodies leads to the formation of a long narrow gap, within which the large amplification of the water-surface elevation could occur. The coupling effect between the roll motion of the vessel and the water-surface motion within the gap is primarily concerned. Under the assumption that the quay wall of the terminal is infinitely long and fully reflective, the imaging principle and a modified Green's function have been developed to investigate such an effect. Numerical models are developed based on the two proposed approaches, respectively, in conjunction with a higher-order boundary element method. For a small gap width, the p = 1 resonant mode of water-surface motion in the gap can apparently enhance the roll motion of the vessel. The radiation wave owing to the enhanced roll motion can in turn disturb the water-surface motion, increasing the frequency of the dominant peak while decreasing its amplitude. As the gap width increases, the water-surface elevation around the resonant frequency of roll motion gets more and more noticeable, gradually becoming the dominant peak. The effect of the mooring stiffness is also discussed, revealing the existence of a ꞌnon-resonance regionꞌ where no resonance occurs in this specific frequency region. It is also noted that the resonant water-surface motion of p = 1 mode can cause a remarkable amplification of the negative horizontal mean wave drift force, pushing the vessel away from the terminal.