e-mosty March 2019 Long Span and Multiple Span Bridges | Page 18
VI. CONCLUSION
With a 100-year design life, the Chacao Bridge will
improve quality of life, commerce, and tourism for
the Island of Chiloe and the port city of Puerto
Montt.
Figure 11: Renderings of the bridge Courtesy of MOP Chile
The bridge will replace the ferry service across the
rough channel and shorten the trip to minutes.
Improved access and mobility between the
mainland and the island will encourage an influx of
professionals to live and work in the area, creating
the opportunity for new development.
Ultimately, Chacao Bridge will connect the Island
of Chiloe to Chile’s highway system, uniting the
island community with the rest of the country.
V. STUDIES AND ANALYSES
To ensure the safety and serviceability of the
bridge under these conditions, and adhere to strict
environmental qualifications that protect local
flora and fauna, archeological zones, and
aboriginal communities, the project team
performed global analysis and time-history analysis
in addition to multiple engineering studies.
The Chilean government estimates the advent of
improved commerce will result in a 6 percent
social return on investment in the region.
The Chacao Bridge is an emblematic project, as the
first long-span suspension bridge in Chile.
It represents an opportunity for the exchange of
technological know-how among MOP and the
partners participating in the consortium, and
demonstrates that Chile provides a favourable
business climate for developing large-scale
projects.
The analyses investigated factors influencing
linear, non-linear, static, and dynamic behaviours,
and the studies included bathymetric, geodesic,
geologic, geotechnical, seismic, topographic, and
wind climate investigations.
The bridge is located in a highly seismic region.
One of the largest earthquakes in the world was in
1960 in Valdivia which is located between Talca
and Chiloé Island.
References:
The structural design of Chacao Bridge was guided
by seismic design criteria according to AASHTO
LRFD Bridge Design Specifications (2012), in
conjunction with Chilean Standards (NCh).
PIZARRO, Diego – HUBE, Matías A. – VALENZUELA, Matías
– MÁRQUEZ, Marcelo: Dynamic Characteristics of a
Longitudinally Asymmetrical Multi-Span Suspension
Bridge: The Chacao Bridge. IABSE Conference Paper, 2015
Geneva.
The seismic analysis focused on specific response
criteria for both bedrock and soil behavior. The
effects of wave impacts in the event of a tsunami
also had to be considered. This comprehensive
probabilistic seismic hazard analysis (PSHA)
defined the structural response to seismic activity.
JAKOBSEN, Svein Erik: Design of Chacao Bridge – Lessons
learned. Teknologidagene, Statens Vegvesen, November
2018.
https://www.arup.com/projects/chacao-channel-bridge
https://www.aas-jakobsen.com/projects/chacao/
Quite extensive aerodynamic studies have been
carried out; they are fundamental to guarantee the
stability of the bridge. They are also distinct from
the wind studies, which were just used to
determine the wind parameters for the bridge
design and the aerodynamic studies.
Wind tunnel analysis studied the bridge’s
aerodynamic stability both in parts (deck, towers,
suspension cables) and as a whole.
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