Today the team set off early from Manta and headed to Bahía de Caráquez to spend the morning with the Ecuadorian Army Corps of Engineers. The ‘Los Caras’ bridge connects San Vincente in the east to Bahía de Caráquez in the west. The bridge is the longest in Ecuador and is critical for connections to the coastal areas of Canoa, San Vincente, Jama and Perdenales from the South. The bridge deck is base isolated using triple pendulum dampers at each pier. The designer of the bridge joined us and told us about the design of the structure and its performance in the earthquake. The bridge performed very well, with some localised soil movement meaning that the capacity of the seismic isolators was exceeded in only one location. This will be replaced and some soil strengthening works will be built around that specific pier.
During the design and construction of the bridge, there was a lot of politics in play, with the army managing to reduce the overall project cost, and thus justifying a 3% increase in spend to include the seismic isolation system. It is a good job they did!
The team spent about an hour in a military boat organised by Major Querembas and Colonel Ramos to inspect the bridge from the water.
We also travelled to some sites of damage within Bahía with examples of poor construction were evident in failed columns with insufficient cover and hence completely corroded rebar.
Finally the team travelled to the hospital which appears to be very damaged, however the it is mostly non-structural damage, with only very minor structural damage to the structural RC frame and shear walls observed. There also appears to have been some differential settlements beneath the ground floor slab. Following the 1998 earthquake the hospital was retrofitted to improve seismic capacity and the new damage from the most recent earthquake has exposed the steel jacketing, see below:
Tomorrow the geotechnical team will travel to San Insidra to survey some large landslides, whereas the structures and the social science team will spend time in Canoa, Jama, and arrive in Pedenales ready for the next days work.
eefitmission.wordpress.com 