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. 1/2019