Temporary access ramp to minimise disruption

Finding ways to minimise disruption during construction within a live hospital saw our team devise an innovative temporary works solution.

The Auckland District Health Board A40 Central Plant and Tunnel project is situated within one of the busiest parts of the Auckland Hospital campus. Without mitigation, our construction traffic would need to travel through public access areas and past sensitive medical facilities.

Recognising the potential disruption, during the tender phase our team developed an alternative route and access for construction traffic involving a temporary, elevated access ramp. The ramp is designed to carry construction traffic away from sensitive buildings and to allow members of the public to pass safely underneath.

The ramp is approximately 36 m long with a 17% slope. The steel superstructure will be supported by 12 unreinforced concrete piles encased in 450mm diameter steel casings, designed to enable installation within agreed noise and vibration limits.

Some major challenges our team overcame during the design of the ramp included:

  • Minimising the ramp angle to ensure suitability for construction vehicles,
  • Working within allowable surcharge loads on existing permanent structures, such as a retaining wall and the existing service tunnel,
  • Ensuring no clashes between temporary piles and the existing / new underground utilities, and
  • Maintaining safe access for members of the public during ramp construction.

For added cost and sustainability benefits, some of the concrete and steel members will be reused from Old Mangere Bridge Project and other temporary works currently in storage.

This innovative solution is now in detailed design, being prepared for Building Consent exemption and construction.