Roleystone DN760 Pipeline Replacement Stage 2

A unique challenge in the connection to existing pipework was the technique in the welded joint interface with the original locking bar pipe. The lead filled locking bar joint requires experience and attention to detail during welding, to avoid destroying the seal of the existing pipe.

At three horizontal to one vertical, the slope of the Butcher Road hill is a significant challenge to safety traverse on foot, let alone in a vehicle or machine. The selection of excavator and more importantly the operator is key to safety in construction. DM Civil has the depth of experienced operators and the project and construction managers to ensure that the operator with sufficient skill and experience was selected for this task. This depth of ability is a crucial factor in the selection DM Civil for high risk construction projects.

The Canning River crossing at the bottom of the slope from Butcher Road presented a challenge, both in preventing siltation from the cleared and stripped bare earth surface along the pipeline route, as well as preserving the river bed. Protection from siltation was achieved by forming herringbone runouts down the slope and placing filter material in combination with retention of the lower vegetation. Preservation of the river bed and banks was achieved by constructing a complete pedestrian bridge.   

Deep crossings designed for Butcher Road and Soldiers Road were problematic when excavation revealed unweathered solid granite. With blasting ruled out as an option, both crossings were redesigned with constructability advice provided by DM Civil to provide workable solutions. A reconfiguration of the Soldiers Road interconnections to the pumping station was also required to be redesigned with the help of the DM Civil engineering team.

Overall Benefit

The project faced many challenges including preservation of the Canning River, working on extremely steep slopes and segregation of livestock from construction work zones. DM Civil was commended by the client for delivering the project without incident or complaint despite design challenges and a winter weather suspension.