In October 2021, BC Hydro reached a major milestone on the Site C project with the completion of the project’s roller-compacted-concrete program.
Since the program began in 2017, crews have placed a total of 1.68 million cubic metres of roller-compacted concrete in three large buttresses, or foundations, that support the powerhouse, spillways and the dam abutment.
The three buttresses are a key component of the Site C project’s design. Combined, the buttresses measure approximately 800 metres long and up to 70 metres wide and will ensure the stability of the dam structures, including in the unlikely event of a major earthquake.
After BC Hydro’s Revelstoke Dam, the Site C buttresses form the second-largest concrete structure in B.C., and the largest roller-compacted concrete dam structure in Canada.
Roller-compacted concrete has many properties similar to conventional concrete, but is constructed with a placement method that makes it well suited for large-scale dam construction. This concrete was manufactured on-site and then transported by trucks to the buttresses.
The powerhouse buttress was completed in 2018, the upper spillway buttress in fall 2019, and the dam and core buttress in October 2021.
Quick facts:
- There are four roller-compacted concrete dams in Canada, with the Site C structure being the largest by volume.
- BC Hydro’s Revelstoke Dam is the largest conventional concrete structure in B.C., with a total volume of 2.2 million cubic metres.
- The three Site C roller-compacted concrete buttresses contain a total of 1.68 million cubic metres:
- dam and core buttress: 450,000 cubic metres (completed 2021)
- spillway buttress: 650,000 cubic metres (completed 2019)
- powerhouse buttress: 650,000 cubic metres (completed 2018)
- The total volume of the Site C buttress is six times the volume of concrete used to build the Burj Khalifa in Dubai, the tallest building in the world.
- Learn more about Site C dam safety measures
- Video - Site C: 2 million cubic metres of concrete is a lot of stability