ABSTRACT
ABSTRACT: As part of the E39 fjord crossing project The Norwegian Public Roads Administration (NPRA) performs a feasibility study for crossing the 5 km wide Bjørnafjord. One of three alternatives for the crossing is a multi-span suspension bridge on floating foundations. The suspension bridge consists of three main spans at 1385 meters each. The superstructure is supported by two land based pylons and two floaters midfjord. The design of the floaters are based on known tension leg platform (TLP) technology from the offshore industry that has proven to be an effective concept for floating constructions at large water depths. The fjord has a depth of up to 550 m, and the seabed is dominated by marine clay in the anchor areas. These conditions are ideal for a TLP solution with anchors combining gravitational and suction abilities. The main concerns for a multispan suspension bridge of this type are addressed to dynamic response induced by environmental loads, such as wind, wave and current, and the ability to withstand accidental loads, such as ship collision. Initial analyses of the TLP concept have shown it is a feasible alternative for crossing the Bjørnafjord, and that the structure should cope with the load conditions for the site.
