CCNZ / HIREPOOL CONSTRUCTION EXCELLENCE AWARDS 2015
Back to the future
with historic Christchurch bridge repair Generations of people have enjoyed crossing over and punting under Christchurch’s historic Armagh Street Bridge. Thanks to Downer New Zealand’s sterling repair work, the bridge can now be enjoyed for many more years to come.
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CATEGORY
PROJECT: Armagh Street Bridge Repairs, Christchurch CONTRACTOR: Downer New Zealand
8 Civil Contractors NZ in association with Contractor magazine
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feature of the Christchurch cityscape since 1883, the arched Armagh Street Bridge suffered terrible damage in February 2011’s earthquake. Sadly, it was rendered impassable to pedestrians and vehicle traffic, including Christchurch’s famous tramway. Most significantly, the earthquake caused yawning cracks on the brick ‘soffit’ (underside) of the bridge, as well as on its ‘extrados’ (outside arch). Approaches to the bridge and original cast iron balustrades also sustained damage. Enter the bridge’s white knight – Downer New Zealand. Ably overseen by site engineer Tom Harding-Ilott, all repair works were undertaken by the Downer team under the Stronger Christchurch Infrastructure Rebuild Team (SCIRT) alliance. Downer and a bevy of subcontractors got stuck into the repairs in March 2014. Core structural repairs saw a sophisticated method of crack stitching and cross pinning used. This involved the drilling of 12mm stainless steel threaded rods into the brick at a 45 degree angle. And 6mm stainless steel bars were installed in the bridge’s mortar joints to tie new brickwork into old. Rounding out the crack repairs was a specially blended, injected mixture of cementitious grout. The work was not without its challenges. Chief among these
