Technical details
Chilean Ministry of Public Work

March 2014: project Start
December 2018: project completion

Preliminary Studies, Basic Design and Detailed Design
Chacao, Chile
Suspension bridges

The Chacao suspension bridge, which connects Chiloé Island with mainland Chile by crossing the Chacao Channel, is the longest suspension bridge in Latin America. This project has been launched by the Ministry of Public Work of Chile (MOP) to boost the economical development of the area by facilitating the access to the island.

The Chacao bridge is the world’s longest double suspension bridge with three pylons. The bridge is located near an active fault, and it is designed to resist severe seismic motion.

SYSTRA, along with JV Partner, AAS-Jakobsen, was responsible for the full detailed design of the bridge. SYSTRA led the seismic studies and design, geotechnical engineering, and the design of the steel orthotropic deck, central pylon, suspension cable anchor blocks, and foundations.

The key technical challenges on this project are associated with the geometry of the bridge with two main spans and with the design under the seismic loads and the wind loads. Among others the contract included the determination of basic engineering data such as seismic and wind input data. One of the main challenges was to find an agreement on the design methodology for the concrete pylon under seismic loads as this type of bridge is not covered by the AASHTO code.

Project key figures

  • Total Bridge Length: 2754m
  • Main Bridge Length: 2494m for 4 traffic lanes
  • Main Spans: 1155m and 1055m
  • Width: 23.8m
  • 2,634m steel deck (main span and approach sections) for 4 traffic lanes
  • 3 Concrete pylons of more than 120m in height: 157m, 175m and 200m height founded; on deep foundations

The project in pictures