Hook Underpass, concrete stiffened steel box beam, bridge replacement, footbridge design and build,

HOOK UNDERPASS

OVERVIEW

OVERVIEW

The pedestrian footbridge crossing over the A3 at the Hook Underpass was due to be replaced to widen the crossing to incorporate upgraded cycle lanes within the area. The existing bridge had to be removed, foundations removed, and new, wider foundations installed, and a newly fabricated bridge installed.

Hook Underpass, concrete stiffened steel box beam, bridge replacement, footbridge design and build,

Closures of the A3 had to be kept to an absolute minimum so one closure was booked for the removal of the exiting bridge and one for the install of the new bridge. Closures could not be organised to remove and replace the existing foundations and the approach roads on and off the roundabout had to remain accessible throughout the works.

THE CHALLENGE

THE SOLUTION

Temporary works were designed by Topbond to allow the demolition of the existing foundations and casting of new foundations in-situ with a minimal footprint and without a risk to traffic below on the A3. RMD Megashores were installed against the existing walls to provide a crash barrier at high level to protect the traffic below. This allowed for most works to be completed on days, avoiding impacting residents with noisy demolition through the night.