The conceptual design of a roadway SFT in Baja California, Mexico

The Submerged Floating Tunnel (SFT) is an innovative water crossing solution under development. It is considered convenient against conventional structures for wide and deep water crossings. SFT is environmentally friendly, as it is submerged, and cheap over long distances thanks to modularity. No SFT has been constructed yet, however many feasibility studies have been proposed worldwide. The improvement of offshore and tunnel engineering provides important tools for making SFT a reality in a near future. This paper describes the conceptual design of a SFT for crossing the Gulf of California linking the mainland of the northwest of Mexico to the Baja California peninsula. This represents a great challenge due to the severe environmental and territorial conditions, with distance longer than 100km and sea depth up to 3km. Together with structural and environmental design issues, leading to the selection of the location of the SFT, the cross section types, the anchorage and foundation systems, the access structures are defined also through a focus on the specific structural safety measures and safety equipment required for the tunnel service.