This thesis presents a prestressed and modular design for relieving platforms in deep-sea quay walls that reduces concrete usage, thereby lowering carbon emissions, and enabling future upgrades.

About 37% of the world’s CO2 emissions come from the built environment, making it a significant contributor. To address these issues the Port of Rotterdam has set sustainability goals, which include becoming climate neutral by the year 2050 and reducing CO2 emissions from material consumption by 25% by the year 2030. This thesis has contributed to these goals by designing and optimizing a modular prestressed relieving platform for deep-sea quay walls, that has reduced material usage and carbon emissions. The focus lied on the relieving platform floor, creating a flexible and upgradable quay wall structure. The application of post-tensioning has been investigated in the design of the relieving platform. Several different prestressing variants have been designed, parameterized and later optimized. In addition a parametric cross-section optimization has been performed by creating an opening around the neutral axis, that further reduced the concrete usage in the floor. A final design of the relieving platform floor using a total prestressing tendon area of 4.500 mm2 per meter resulted in a minimum cross-section height of 890 mm and an embodied carbon reduction of 20%.

A prefabricated, modular solution has been designed that enables the upgrade of a quay wall structure by allowing for the relieving platform floor to be added at a later stage. The building sequence has been designed with a focus on efficiency. The modular design benefited from the weight reduction of 50% that resulted from the application of prestressing. Three main connections have been designed, for which several solutions have been proposed, namely: the module-to-module connection, the module-to-wall connection and the module-to-foundation pile connection. Particular attention is given to the placement of the prestressing anchor on the water side of the relieving platform, for which two alternative solutions have been proposed.

The findings of this thesis show that prestressing can play an important role in creating
lightweight, lower-carbon and modular relieving platforms for deep-sea quay walls. It has
allowed for a significant material reduction, crack control and weight reduction, facilitating
the prefabrication of the floor. This design offers a flexible, upgradeable and lightweight
alternative to traditional the relieving platform design.