The proposed long wall underground mining at West Cliff colliery in Appin, NSW will result in general subsidence across the area. The predicted increase in stresses on two natural transmission pipelines and one ethane pipeline at the Mallaty Creek crossing required mitigation works to avoid overstressing of the pipelines resulting in possible ruptures and disrupting natural gas supply to most areas of NSW. GHD provided engineering solutions consisting of decoupling the buried pipelines from the ground to relieve the increase in stress and reduce potential damage to the pipelines.
Firm Name: GHD Pty Ltd
Client: Alinta
Project Owner: Alinta