Self-Bearing Shotcrete in Lieu of Self-Consolidating Concrete for Tunnel Rehabilitation

摘要

Pennsylvania Department of Transportation’s almost 100 year old Liberty Tunnels underwentrnsignificant rehabilitation measures, including the replacement of aging ventilation arch walls. The arch wallsrnact as tunnel shaped jet structures for fresh air supply. The original design foresaw the use of self-consolidatingrnconcrete and formwork for the replacement. The authors developed an alternative concept and subsequentrndesign for a shotcrete arch wall solution in lieu of the self-consolidating concrete foreseen by the contractrndesign. The alternate shotcrete concept provided the contractor with a schedule and cost saving solution underrnthe given tight, two week long, construction window allowed during a complete shutdown of the tunnel.