Behavior of Instrumented Base-Isolated Structures during the 27 February 2010 Chile Earthquake

Several buildings and bridges with base isolation were in the area struck by the 27 February 2010, Mw 8.8 Maule earthquake. A building and two bridges that were instrumented with networks of accelerometers registered the quake; these records are analyzed here. Results of this kind are very valuable because a strong motion earthquake of large magnitude occurs only from time to time, and these rather new types of structures had not been exposed to such severe action. The isolated building is a four-story reinforced concrete and confined masonry structure located in the city of Santiago. The bridges are: (a) a 368m long continuous bridge located in Viña del Mar and (b) one section of a Santiago metropolitan train viaduct. Results show important reductions in horizontal accelerations, especially at the roof level of the building (to nearly 20% of the twin fixed-base case), and in the longitudinal direction of the bridges.