Tall Building Behavior During the 3 March 1985 Chilean Earthquake

On 3 March, 1985, a major earthquake of magnitude Ms=7.8 occurred off the coast of central Chile. The affected area included the most populated area of Chile and the cities of Santiago and Vina del Mar, where many tall buildings exist. The Chilean earthquake of 3 March, 1985, was particularly significant in that the ground motion was well recorded, was of strong motion and long duration, and modern structures performed extremely well (Wyllie 1986). Although the design forces for buildings in Chile are comparable to those in the U.S., the Chilean engineers developed a structural design philosophy that is unlike those in the U.S., Japan, or other regions of high seismicity. Most moderate-rise residential buildings in Chile rely on reinforced concrete structural walls to resist lateral and gravity loading. In general, the walls have moderate amounts of reinforcement without special detailing for producing a ductile structure (Wood 1991 ).

The main objective of this report is to review and evaluate the performance of tall buildings during the 3 March, 1985, Chilean earthquake in order to improve the seismic design of high-rise reinforced concrete buildings, particularly when they have to be built on soft soil.