Single traffic lane steel tube for low cost road tunnel construction

摘要

The tunnel sections are prefabricated round tubes (3), preferably steel, and up to 40m in length. The tube diameter is as small as possible, allowing adequate clearance for a single traffic lane carrying a maximum size of vehicle. The sections are connected with flexible watertight couplings, and laid in parallel according to the number of lanes required. The tubes are provided with brackets (12) for anti-buoyancy rods or cables (11) for connecting to deep ground anchors (9,10) before the completed tunnel is pumped out. The roadway (4) is concreted (20) and includes drainage (21) and additional longitudinal tunnel reinforcement if necessary. Lighting and other services are housed in the void segments (19).