Colombia is a mountainous country located in the active seismic area called the Pacific Ring of Fire. Added to this is the convergence of three tectonic plates (Nazca, Caribbean and South American plates), which movement produces several types of geological faults that can influence the frequency and intensity of earthquakes, depending on the region of the national territory on which it is located.
Even though Colombian people are not used to earthquakes and the topic is disregarded, the vulnerability concerning seisms is very high. Particularly, in the Aburrá Valley it does not take a strong earthquake for there to be considerable damage, hence the need to be prepared.
This is why four years ago the School of Engineering of Universidad EAFIT, through the department of Civil Engineering, was contacted by the Global Earthquake Model (GEM) foundation, a non-profit organization that works to improve resilience to seisms around the world.
Ana Beatriz Acevedo Jaramillo, PhD in Seismic Risk Reduction and professor at Universidad EAFIT, was invited to take part in the South America Risk Assessment project (SARA) as a national expert. The seismic risk along the region was measured in the project, which allowed in determining both human (injured or dead people) and financial losses after an earthquake.
The task of the researcher was the development of two models: a presentation model that helps identify the amount of buildings in the city, their construction features and the amount of people living there. A vulnerability model for the most common type of houses, that allows the identification of the possible damage of these structures in case of an earthquake.
The professor Juan Diego Jaramillo Fernández and, at that time, the student of the Master’s in Engineering, Fernando Alexis Osorio Vergara, also made up part of the project. The study showed that more than half of the housing in Medellin is not built to resist earthquakes. They are houses built out of bricks which are placed one over the other without iron in the walls, no columns and no beams, even though this type of construction is banned in the country.
The importance of this project lies in its capacity to calculate the possible losses produced by earthquakes in the region. Thus besides the knowledge of the infrastructure outline, it is necessary to calculate how such structures work in Latin America.
Since an important amount of the houses in the region is sui generis, as is the case of the most common type of houses in Medellin, professor Juan Diego Jaramillo states that in order to analyze the capacity of these houses in Medellin, it is necessary to complement the current local information with that of other countries that have similar houses. This is the objective on which the EAFIT team has been working.
Local Model
The Universidad EAFIT team, with the SARA project, created a presentation model for making large-scale measurements in seismic risk studies, specifically for the Department of Antioquia and in more detail for Medellin, Bogota and Cali.
The Medellin model was optimized as recommended by Daniela González González, a student of the Master´s in Engineering, who is currently a PhD student of the Engineering program. More surveys were conducted and Bogota and Cali models were improved afterwards.
The SARA project was completed in 2015, but EAFIT researchers continued working with GEM foundation. A cooperation agreement was then signed between EAFIT and GEM in 2017, and in May of that year a Seminar-Workshop on the assessment of seismic risk and its implications for decision-making was conducted.
Upon completion of his Master’s degree in engineering, Fernando Alexis Osorio, a current PhD engineering student at EAFIT, decided to focus his thesis on the study of the seismic vulnerability of the non-reinforced masonry infrastructure that represents 60 percent of the housing at Valle de Aburrá.
Through lab tests, the doctoral student has been applying loads to non-reinforced masonry walls to study their behavior with lateral loads. The objective is to obtain data to create models, measure, and understand the behavior of the structures of these types of constructions which have very low capacity to withstand seismic loads.
These tests make up part of the activities of an association agreement between EAFIT and the Metropolitan Area of Valle de Aburrá. Since the vulnerability of non-reinforced masonry housing is a problem in the region, it was decided to complement the trials of the doctoral student with wall trials on the vibrating table, which makes it possible to apply accelerations on the base of the wall.
José Fernando Baena Urrea, onther student of the Master´s of Engineering, supervised the trials on the table. All the experimental trials are done in the Seismic Lab at EAFIT, one of the most complete and advanced labs of the country.
To estimate the level of the seismic risk, three components are taken into account: threat (if it shakes or not), presentation (who and what are there) and vulnerability (capacity of the structures). For this task, researchers focused on vulnerability since the objective is the study of the structure behavior, states professor Ana Beatriz Acevedo.
Through the line of research professor Ana Beatriz Acevedo leads, it is expected that they find solutions to reduce, in the best possible way, the consequences of a possible earthquake. It is also an expectation that leaders and people in general understand the importance of prevention and meeting the construction requirements, for both taking care of the heritage and most importantly, to save lives.
Further information for journalists
Alejandro Gómez Valencia
EAFIT Information and Press Area
Telephone: 574 2619500 ext. 9931
Email: jgomez97@eafit.edu.co