Since most of the existing port infrastructure needs to be upgraded or replaced in the coming decades, the Port of Rotterdam Authority invests in sustainable and future proof design solutions. Together with their partners, they aim to reduce the port’s CO₂ emissions by 50% in 2030 and intend to achieve a zero carbon footprint by 2050. The effective use of new and existing materials is crucial to reach these goals. However, the actual capacity of port infrastructure is generally not precisely known, given that no failures have been observed in practice and the existing berthing facilities are performing very well. In order to derive insight into the reserve capacity of these structures, unique full-scale field tests have been conducted on flexible dolphins, foundation piles and anchor piles. This paper presents the technical, commercial and environmental results of recent pile load tests performed in the port of Rotterdam. The tests have led to a significant reduction of CO2 emissions associated with manufacturing and installing foundations, as well as reducing installation risks. Furthermore, a higher reliability level was obtained using less materials. This paper shows that in spite of the cost of performing full-scale field tests, the verification of the actual capacity of foundation piles is crucial to improve the carbon footprint of port infrastructure.
... Read more

A newly developed line-style sand pluviator has been calibrated to prepare repeatable sand specimens of specific statuses of compactness and homogeneity for laboratory tests. Sand is falling via a bottom slot of a fixed hopper, and by moving the sample container under the slot, the container is evenly filled with sand. The pluviator is designed with high flexibility: The falling height of sand, the hopper’s opening width and the relative moving speed between the hopper and the sample box can be easily adjusted. By changing these control factors, sand specimens of a wide range of densities can be prepared. A series of specimen preparation was performed using the coarse Merwede River sand. Performance of the pluviator was systematically evaluated by exploring the alteration of achievable density, as well as checking the homogeneity and fabric of the prepared samples by CT scanning. It was found that the density of prepared coarse sand samples has monotonic correlations with none of the three control factors. Furthermore, CT scanning results suggested that the prepared samples exhibited excellent homogeneity in the horizontal direction but periodical alteration of density in the vertical direction. Based on these calibration test results, a preliminary hypothesis is proposed to describe the general working principles of this type of pluviators a priori, illustrating the mechanisms dominating the non-monotonic correlations between control factors and the relative density as well as the vertically prevalent heterogeneity of specimens. Accordingly, practical recommendations are made in a unified framework in order to lessen the load of similar calibration work. ... Read more

This paper describes axial load tests on three full-scale driven precast piles in the Netherlands. The piles were founded in dense to very dense river-deposited sands, a soil that is widespread across the Dutch North Sea sector. The deposit is characterised by cone penetration test (CPT) tip resistances of up to 90 MPa and offers a detailed insight into pile response in realistic offshore conditions. Each test pile was incrementally loaded to failure under compression, while fibre optic sensors measured the changing deformation of the pile. The analysis and interpretation of the load test data focussed on how the three slender piles behaved at large shaft and base resistances. Notably, the piles mobilised base and shaft resistances greater than currently prescribed limiting resistances in design standards, thereby highlighting some overconservatism present when designing piles in dense sand. ... Read more

Large areas of the Netherlands are dominated by deep, soft soil deposits, posing a challenge to engineers with respect to the design of axially loaded foundations. The design of these foundations is primarily based on methods which use cone penetration test (CPT) parameters, such as that outlined in the Dutch national standard NEN 9997-1. A recent update to this standard included revised reduction factors for the pile base resistance. However, it is believed that this update is overly conservative in certain design situations, leading to increasing cost, environmental impact and difficulty of installation. As a result, a national research project was initiated to enhance the understanding of pile-soil interaction effects and their influence on pile design methods. As part of this project, a series of large-scale field tests on fully instrumented piles in dense sand has been executed and are being analysed with a view to refining the national standards and contribute to the existing knowledgebase on piles worldwide. This paper shall provide an overview of two pile test sites that have been developed as part of the programme, along with the design of the testing programme and an overview of the results. ... Read more