DSC_0321.JPGGFWAust were appointed to stop the water ingress entering the completed pipejacked tunnel and shafts.

 

 

 

 

DSC_0311.JPGThe underground cable tunnel beginning in Campbell Road,  running  below  Burrows  Road,  and  finishing  at  the  Energy  Australia / Transgrid  Substation  in Alexandria was constructed by Abergeldie.
The  project  features  an  launching  shaft,  an  87m  long  pipe-jacked  tunnel  and  a  receiving  pit. The tunnel was constructed by an EPB TBM through waterlogged sand, The shafts were constructed by secant piling.
On completion of the shaft and tunnel construction GFWAust were appointed to stop the water ingress.
The secant piles were leaking at the intersection between soft and hard piles and at the intersection with the shaft floor slab. Water ingress was at a rate of about 20 litres/minute. GFWAust sealed the leaks with water stopping mortar and injection of polyurethane.


Bernie.jpgGround water in the tunnel was ingressing at the tunnel eye where the tunnel entered the shaft through the secant piled wall. GFWAust injected polyurethane near the portal to stop the leak before injecting a precision non-shrink grout to form a permanent seal.
Water ingress was stopped allowing Abergeldie to complete the concreting works.