Stays made of expressive and optimized steel plates
The bridge is a hybrid of typologies: double metal beams combined with a suspended system that forms a mixed structure, which is at the same time expressive and optimized. In the longitudinal direction, the longitudinal beams express the flow of force: they carry the loads from the main span of the bridge to the supports, where the pylons deflect these forces towards the ground. At the connection between the anchor beam and the deck, the horizontal component of these forces is taken up by the concrete deck in the longitudinal direction. In the middle of the span, the section of the profile becomes more compact and works in bending. The position of the deck varies in the height of the composite beam in order to remain constantly in compression: both where the bending moments are negative (on support) and positive (in span). This ideal division of roles – the steel in tension and the deck in compression – stiffens the complete structure and avoids cracking of the deck, reducing future maintenance.
The fluid shape of the metal plates is purely driven by their static requirements: smooth changes in stiffness ensure that there are no large stress spikes to easily meet fatigue strength requirements. At the rear of the bridge, the selfweight of the approach deck as well as that of the foundations take up the permanent uplift loads. The groups of micropiles take up the useful loads of the bridge and add stiffening to the structure. Pendulum columns connect the deck to the foundations, which allows the bridge to expand horizontally while transferring small uplift forces to the foundations.
