The influence of spatial variation on the design of foundations of immersed tunnels: Advanced probabilistic analysis

Immersed tunnels are positive buoyant structures during installation and negative buoyant after installation. A tunnel is composed of sequential immersed elements that are coupled to each other in joints. Tunnel elements consist of segments which are compressed to each other by longitudinal post-tensioning. After immersion the tunnel is...

Managing Knowledge for Future-proof Tunnels in the Netherlands

Determining the scope of (structural) renovation of aging tunnels is a complicated task and modular renovation is becoming increasingly necessary. The COB Tunnel Programme aims at developing the knowledge necessary to renovate these tunnels in a modular fashion, to reduce hindrance as much as possible. Part of this program is the development of...

Re-use of immersed tunnels: An innovative method for recovering, regenerating and reusing immersed tunnels by temporarily re-floating

Immersed tunnels, located in waterways, could be a limiting factor in the dredging in waterways. This dredging is required since cargo vessels draught increased the past decades. In this thesis a new method is defined for temporarily, effectively, re-floating immersed tunnels. With this method extra risks arise, for these risks’ measures are...

Ship collision on temporary structures: Combi-walls under collision loading

When designing a construction pit adjacent to a navigation channel, the event of a ship colliding with the structure is something to take into account in the design of the pit. However, several aspects regarding ship collisions, i.e. the probability of occurrence of a collision, the magnitude of the collision force and the influence on the...

Probabilistic analysis of immersed tunnel settlement using CPT and MASW

Settlement data of the Kiltunnel and the Heinenoordtunnel show that immersed tunnels in the Netherlands have been experiencing much larger settlement than expected when designing the tunnels causing cracks in the concrete and leakages in the joints. Settlements of 8 - 70 mm have been measured at the Kiltunnel and of 7 - 30 mm at the...

Insufficiency of immersion joints in existing immersed tunnels: Case study on functioning of Gina-seal and Omega-seal in the Kil Tunnel

In 2009 and 2010, two leakages through immersion joints occurred in the First Coen Tunnel near Amsterdam. From the study on t-he cause of these leakages, it followed that there was a potential problem for existing immersed tunnels: failure of the temporary Gina-seal combined with corrosion on the clamping structure of the definitive Omega-seal....

Impact of spatial variability of subsoil stiffness on immersed tunnels

Due to increased traffic density, there is a tendency to construct larger immersed tunnels with larger tunnel elements both in transversal and longitudinal direction resulting in a more critical design of the joints. Especially for those tunnels with relatively soft foundation and high siltation, there is no mature experience for reference. This...

Dynamic Stability of Tunnel Elements During Immersion and Transportation

Immersed tunnel elements are prefabricated in the construction yard and then transported to the construction site to be integrated into the tunnel. During the transportation and immersion, the floating tunnel element is connected via cables to the immersion barges/pontoons. In this study, the hydrodynamical behavior of a floating tunnel element...

Investigation on Stress Increase of Sand Inside Immersed Tunnel Joint Gap

Watertightness and leakage prevention is crucial in every tunnel joint design. Immersed tunnels have been utilizing the Gina-Omega gasket solution since the 1960s to prevent leakage from occurring. However, after almost 50 years of service life, leakages were detected in the immersion joints, which leads to an investigation into the source of...

Steel–Concrete–Steel Sandwich Immersed Tunnels For Large Spans

Traditional reinforced concrete tunnels show limits regarding large spans in the transverse direction. There was a lack of knowledge whether the steel-concrete-steel (SCS) sandwich tunnel can be a solution for tunnels with extreme large spans. Research was needed to understand the structural response of a large span SCS tunnel to the load...