This project aimed to understand the key aspects of the behavior observed in shear wall buildings that underwent seismic damage during the February 27th, Chile earthquake. About 2% of the more than 2000 buildings of 9 stories or more that compose the building inventory suffered a type of failure that had no precedent in the earthquake literature. The novelty of this behavior made us propose this research that is composed of three main methodology approaches. The first one was based on collecting all possible field information of the observed behavior, and based on simple statistical correlations between the building properties and the observed response, derive conclusions about patterns that could be used to identify those structures with a larger vulnerability. The second approach was to tackle the problem by generating a deeper understanding using experimental analysis on a group of 9 walls in ½ geometric scale that represented the as-built conditions of these walls. The goal for this experimental campaign was to reproduce the brittle behavior observed in practice, and starting from there, derive design guidelines and conclusions to improve the observed behavior. And the third approach, was to develop a new capacity to improve the design of these elements and buildings in general by attempting reliable analytical modeling of the cyclic behavior of the walls and resistant planes using currently available inelastic modeling and analysis tools, developing others, and proposing improvements in the behavior by incorporating energy dissipation elements and techniques to reduce the inelastic demand on these shear walls.

This very ambitious and comprehensive project has led to a rather large scientific/technical productivity and a very important knowledge-base that would enable all of us continue learning about these very important structures and their unexpected earthquake behavior. All the goals of the project were achieved. But more important than that is the fact that the project has led to results that may help the engineering profession immediately, and at the same time, allow researchers to start several new very promising lines of research that could be complementary and needed to address comprehensibly this very critical behavior of shear wall buildings, the most common structures used in Chile. The bad news of this research is that to the best of our knowledge, the observed behavior was very brittle, which contradicts completely one of the fundamental principles and strongest design assumptions of the current design codes, which are based on a hypothetical important dissipation capacity of these structures. Consequently, it is urgent that in light of these and other researcher results, our country develops a very comprehensive review of the existing building stock and provide recommendations to the owners of the true fragility of these structures, and eventually propose a retrofit strategy for some of these structures. Perhaps the strongest conclusion of this study is that it is wise to be better safe than sorry, and produce a correct diagnose of the situation of many existing buildings.

In academic terms, this research has led to very significant products. In terms of students, 18 researchers worked in this project: 1 undergraduate thesis, 13 master students (11 finished and 2 are in progress), and 4 Ph.D. students (1 finished, and 3 other in progress). Regarding publications, 12 journal publications were presented, 4 already published, and 8 others sent for review. Furthermore, one patent (in review) also originated from the work of one of the Ph.D. students, and seven international conference papers have also been presented. Another important academic result is that the project enabled us to develop very important international connections and fruitful relationships with professors from U.C. Berkeley, UCLA, Johns Hopkins, MIT, and ETH Zurich.

Apart from its academic impact, the project has (and will) generated other very positive and promising consequences in the society. For instance, the productive exchange of three of our researchers to the leading research groups at the USGS and Johns Hopkins University, the clearinghouse of shear wall building data open to any researcher, the outreach seminars and talks that have been given nationally and internationally about this topic, the input generated to other very relevant research initiatives such as CIGIDEN (Fondap), the pioneering seed fund project MISTI with MIT, the patent, and the possibility to influence a new public policy to evaluate all midrise and high-rise residential buildings in Chile.