Captains Flat Dam Load Monitoring

Project Overview

Fortec carried out the monitoring of the anchors, originally installed as part of the dam wall strengthening in 1992, as part of the periodic monitoring carried out every 10 years as per Dam safety requirements.

Captains Flat Dam is a 17m high concrete gravity dam on the Molonglo River located approximately 50 kilometres from Queanbeyan. The dam wall was strengthened in 1992 with the installation of 19 post tensioned anchors of up to 19 strands.

Monitoring of the anchors was required to verify the residual force in the anchors as part of periodic monitoring which is carried out every 10years as per Dam safety requirements.

Fast Facts

  • CLIENTQueanbeyan-Palerang Regional Council
  • LOCATIONCaptains Flat, NSW

Scope of Works

Fortec tested 19 permanent anchors:

  • 2 x 9 strands
  • 2 x 14 strands
  • 15 x 19 strands

The monitoring methodology was conducted using a custom fabricated load cell consisting of a hollow bottom cylinder, base plate, 5 number 100T hydraulic cylinders, a top plate and a hollow bottom cylinder. The load cell used was calibrated in a NATA accredited facility. The system utilised the existing client supplied stool, anchor coupler, pull rod and lock nut.

Highlights

  • First Dam Monitoring Project on the East Coast.
  • All works were self-performed by Fortec
  • Upgrading the corrosion protection system by providing a HDPE pipe wrapped with Denso tape & filled with Denso void filler.