Sydney's Cross City Tunnel Adopts New Reinforcing Solutions

摘要

Have you ever tried to build a concrete slab upside down? Start with a surface six to seven metres above your head. Then hang the loose reinforcing steel and bar chairs below this surface. Finally suspend the formwork below the reinforcement and pump concrete into the space between the formwork and overhead surface, remembering that air trapped against the overhead surface needs to be removed. Sound difficult? Well that is how a concrete lined tunnel is placed. The Baulderstone Hornibrook Bilfinger Berger Joint Venture (BHBB JV) approached Smorgon Steel Reinforcing for an easier way of placing the tunnel reinforcement at the Cross City Tunnel. The solution provided by Smorgon Steel Reinforcing was simple; two cages of reinforcing steel, fabricated off-site, to create an arch across the roof of the tunnel.