Highway tunnels constructed of concrete enclosed by a double-wall tubular composite structure are shown to be economically feasible and merit serious attention by planners of advanced transportation methods that must contend with water crossings. Modern techniques for mechanically coupling and sealing tubular composite structures are shown to now enable composite materials to compete with welded steel joints in strength and long-term service. Engineering properties and commercial applications of the new class of twined-strand unidirected composite materials are presented along with cost and performance comparisons between composites and identical pipe and tank structures made of steel. A detailed engineering solution to the problem of providing an affordable fixed transportation link between Europe and Africa across the Strait of Gibraltar is presented. This example shows how structural composites can be used with concrete to fabricate the type of highway tunnel envisioned as an inevitable adjunct to conventional approaches used to solve current and future transportation problems.
Abstract