Client: Wellington Water

Consultant: WSP

Head Contractor: Juno Civil Ltd

A local reservoir in need of emergency structural repair and strengthening was the first recipient of the BBR VT CMW technology in the Wellington region.  The CMW hardware (as shown) was used as the anchorage of choice for 100m long tendons.  Two sets of anchorages were placed around the circumference of the reservoir, positioned approximately 180 degrees from each other – making a total of 4 of the BBR VT CMW 206 anchorages. 

 The tendon was made up of 4 x 15.2mm greased and sheathed strands, which were placed onto small saddles installed at 2m centres around the circumference of the reservoir.  Once the strands had been installed the anchorages were fitted up into position and made ready to stress. 

Tensioning of the strands was carried out from one anchorage only and the tensioning was completed in two stages.  A 10% UTS load was applied as a first stage of tension.  After further remedial work to the reservoir was complete the final 50% UTS load was then applied to the strands.  

Due to the economical size of the anchorage, angled nose cones were required to accommodate the mono-strand jacks.  Two jacks were used in unison so that two strands could be tensioned simultaneously and to keep the anchorage in balance during tensioning.  

After all strands were tensioned to load the excess strand tails were cropped back and corrosion protection was applied to the strands and wedges.