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Devil’s Gate refurbishment
In 2016, divers and sonar scanning identified some significant erosion of the concrete lined plunge pool below the spillway of Devils Gate Dam which is submerged all year round. The repair is one of the most critical event to be done as the Devils Gate Power Station is due to a major refurbishment in 2018.
Devil’s Gate refurbishment
Devil’s Gate refurbishment
Dam erosion repairs
In 2016, divers and sonar scanning identified some significant erosion of the concrete-lined plunge pool below the spillway of Devils Gate Dam, which is submerged all year round. The repair is one of the most critical events to be done as the Devil's Gate Power Station is due to a major refurbishment in 2018.
The erosion was properly exposed in March 2017 when the plunge pool was drained for the 1st time since the diversion tunnel closure in 1969. Once the damage had been fully assessed, a fast-paced programme of rectification works commenced, which consisted of high-strength reinforced concrete overlays over the whole area of damage. The repair methodology was developed and implemented BridgePro Engineering team.
Technical details:
Key challenges of the project are included:
- Construction barges were used to cart trucks and equipment in and out of the dam site
- Provide a truck access to plunge pool by building a secondary coffer dam
- Repair work was carried out during the daytime while the power station was returned to service at each night, 6 days/week.
- Draining water out of the pool every day to ensure the safe working area.
- Complicated lining shapes at the bottom of the pool where more than 350 m3 of specialised concrete was laid in 8 sections/panels.
- New 600mm depth concrete lining was anchored to rock 4m depth and bonded to existing concrete with special bonding agent
Relevance to B3, R2 pre-qualification categories:
- Construction using coffer dams (B4)
- Large / Significant concrete pours (B4)
- Complex foundations (rock drilling)
- Complex geometry
