Narrows Bridge

Waikato, New Zealand
Transfield Services

The project

Narrows Bridge crosses the Waikato River between Cambridge and Hamilton. The bridge abutments had become unstable.

The issues

Difficult access by conventional means due to:

  • Weak, sensitive soil and rock
  • Daily river level changes
  • Work to be carried out below the river flood level
Meshed rock above a rusty platform at river water level

Our response

  • Meticulous planning and monitoring.
  • Rapid response when necessary.
  • Excellent collaboration between Avalon and the other parties involved in the project (Transfield, BBO and Earthtec).
  • Use of our highly mobile, lightweight rigs.
  • We installed 150 nails 18 metres deep in the bridge abutments then meshed and shotcreted the abutment slopes.
Avalon team members and heavy drill equipment hanging on a rock face
2 Avalon team members operate a rigged horizontal drill above a river

The outcome

Work successfully completed substantially on schedule, on budget and beyond expectations. Avalon also completed the required preliminary work to the abutment stabilisation which involved securing the abutment slope, a logistical challenge but thanks to our innovative technology one completed at around half the cost of the alternative.

Stabilised and reinforce Narrows river bridge abutment