Bridge across the Chacao Channel

Photo: COWI

​COWI-ICUATRO Joint Venture is carrying out the feasibility study and prepares tender documents for the construction of the Chacao Channel Bridge in Chile.

When completed the bridge will form an important link of the Chilean infrastructure, connecting the mainland with the Chiloé Island some 1,000 km south of Santiago. Replacing
today’s car ferries with a dual carriageway fixed link, the bridge will enhance future development in the sparsely populated southern regions of Chile.

At the proposed crossing, the channel is 2.4 km wide and 60 to 80 metres deep except for a tiny shoal, Roca Remolinos, in the middle of the strait. This situation requires cablesupported bridges with towers standing on the embankments and on the shoal.

The more likely solution is a continuous two-span suspension bridge with one A-framed central tower. The area is seismically highly active. The Valdiva earthquake of May 22, 1960 (8.5 on the Richter scale) is the world’s largest ever recorded earthquake and had its epicentre just a few hundred kilometres away from the bridge site. Even if suspension
bridges are fairly resistant to earthquakes, the seismic activity of the region is one of the major challenges for the project to meet.

The bridge design is verified by 3D computer based time history analyses of the seismic design events. Wind forces and aeroelastic stability of the structure are derived from computerised flow simulations and eventually verified by wind tunnel tests.

LAST UPDATED: 23.02.2017