Client: DOWNER UTILITIES AUSTRALIA
Project Value: $4.6 M
Pipeline : 3.5km
Duration: 8 Months
Key Components: Road Construction, Plant Hire, Pipeline Construction, Drainage, Bulk Earthworks.
The Chichester Trunk Gravity Main (CTGM) is an 85km pipeline that moves water from Chichester Dam to the Lower Hunter, including several townships adjacent
to the pipeline route. The CTGM currently operates to supply approximately 80ML/daily, which represents an estimated 38% of the average demand within Hunter Water distribution network.
Works completed by EIRE Constructions included the installation of a 3.5km segment of DN1200 mild steel-cement lined trunk main to the CTGM, a portion of the overall 7.7km long project scope. Weighing more than 6 tons and totaling 13.4m in length, each pipe section was installed into a 1.5m wide x 3.5m deep trench. Ground condition was poor and susceptible to the highly volatile wet weather conditions which presented a few challenges for EIRE throughout the project from trenching to welding.
Working in collaboration with the client and designers, EIRE Constructions developed several solutions to overcome challenges presented. One of which included raising invert levels of the pipeline where possible. This reduced the depth of excavation needed to install the pipeline and overcame obstacles presented by the trying ground conditions. This drastically improved overall safety outcomes by removing the need for shoring boxes in some locations and resulted in a cost reduction for the client.
An effective, risk mitigation-based approach to program management and innovative works scheduling enabled EIRE Constructions to accelerate works traditionally susceptible to delay due to wet weather events. This, coupled with the adaptation and implementation
of certain plant assets, enabled project works to be completed safely, on time, and to the client’s satisfaction.