Sakhalin-1 GBS
One of three seabed‑fixed concrete gravity‑based structures designed for this earthquake‑prone Arctic region, Sakhalin‑1 was engineered to withstand Arctic ice loads, extreme cold and major earthquakes simultaneously. This required unique solutions, including high‑durability concrete and seismic isolation between the substructure and the topsides.
Extreme weather and earthquakes
- Location: Offshore Sakhalin Island, Russia
- Project period: 2008–2011
- Client / Operator: ExxonMobil
- Structure type: Concrete gravity-based structure (GBS)
Engineering design and construction of a concrete gravity‑based structure founded on the seabed in Arctic offshore waters. The structure was designed to withstand extreme environmental conditions and earthquakes of up to magnitude 9.0, incorporating a seismic isolation layer between the GBS substructure and the topsides.
- Water depth: 35 m
- Concrete volume: 52,000 m³
- Reinforcement: 20,000 tonnes (400 kg/m³)
- Tension cables: 1,500 tonnes
- GBS dimensions: 135 × 100 m, height 55 m
- Designed for Arctic offshore and high seismic activity
- Concrete selected for robustness and long-term durability over steel
- Proven GBS solution for extreme environments