Seismic-resistant Architecture:
Examples of Damages to Buildings
By Alexander Varela
The practice of architecture changes constantly throughout time. Technology allows us to create spaces for men that are each time more efficient but it doesn’t sustain by itself. The architect’s criteria are determining to develop an adequate project.
The existence of earthquake-resistant buildings is proof of this statement. Even though technology development in seismic research has grown to the point of being able to detect a seismic event’s origin once it happens, it’s not possible (as of 2020) to prevent when or how it's going to impact.
Therefore, (based on the study of previous seismic events, knowledge of the ground’s conditions, and the existing technology to evaluate the behavior of a building when facing seismic loads) it is possible to approach an architetural project in a way that responds in the best possible way to an earthquake.
We have to consider factors such as form, proportion, space configuration, materials, and structural systems. This is what we know as earthquake-resistant design.
For the most part, not knowing the right strategies is the biggest cause of a poor earthquake-resistant design. It is possible as well that the architect is aware of seismic design criteria, but ignores or dismisses them by prioritizing other factors such as the project’s operability and aesthetics.
We can say all of this assuming that the mistake lies in the design and not in situations such as corruption or lack of management during construction. In any case, there is a substantial increment of risk of damage to the building, and worst yet, of the possible loss of human life.
The non-existent or poor application of seismic design criteria is evident, especially, in Latin America.
Background in Latin America: Nicaragua's Earthquake in 1972
Nicaragua’s Earthquake in 1972 is one of the most important seismic events in 20th century Latin America. It is evident here that the design caused a less-than-efficient behavior for most buildings, several of them belonging to the health and welfare types, which are essential during this kind of situation.
Among the main causes for collapse are:
☑ A short column effect (generated due to changes of stiffness on certain areas of the column, such as windows being on the upper part);
☑ Building using inappropriate materials (most buildings back then were made using taquezal, which is a mix of mud, wood, and stone);
☑ Weak ground floor (ground floors are usually free, and upper levels are much more rigid and heavy);
☑ Bad structural configuration (buildings with good structural configuration stood standing, and buildings with not-so-great configuration collapsed or showed irreparable damage);
☑ Excessive weight on slabs and roofs (which besides being subdued to intense vertical and horizontal movements, are too heavy in proportion to the structure that supports them);
Considering that this event happened over 50 years ago, it's possible to give the benefit of the doubt and think that all this unaccurate design criteria happened because of ignorance in the field of seismic behavior.
However, as time goes by and these patterns keep happening, we cannot believe this as mere ignorance anymore. Other factors come to play here, such as irresponsibility or lack of consideration for the building’s safety, and therefore it’s users.
This can be seen in more recent buildings in Venezuela, where many of these design errors keep happening. And this is taking into consideration that it is planned architecture, designed by professionals and approved by government entities.
Seismic-resistant Architecture A Challenge in Venezuela
It is understandable to overlook some details due to clashes with other design goals, such as function and spatial perception.
Unfortunately, these are not small details but large-scale issues that impact negatively on the building’s seismic behavior and create risks to the user: excessive torsion configurations, weak ground floors, non-structural materials that add excessive stiffness and weight to the structure, abrupt changes in volume, irregular plants, among many others.
And all of this is only regarding planned architecture; the story is even worse among spontaneous urban developments.
Whenever a slum is seen in any part of the country, with spontaneous and high-risk growth, usually the first thing that comes to mind is: How can they build in such an irresponsible way?
And there’s an answer for that: No architect with the most basic knowledge, common sense, and scruples would offer to build on such a context.
We can presume that most spontaneous construction is made by workers, that are not aware of the risks in building this way, and whose names do not appear on tangible construction documents, and therefore are hard to receive any criminal or civil liability.
Based on the above, it's safe to say that bringing seismic design criteria into Venezuelan architecture is, in general, deficient at best, and non-existent at worst. The big question is: Why? And there are not one but several factors, among them:
Governance
On top of the previous issues, we have to add poor supervision from government entities to Venezuelan construction, especially on the topic of seismic resistance.
It’s helpful to remind that the current seismic-resistant buildings norm is over 20 years old. Since then, knowledge of structural calculus and design went forward around the globe.
If these advances were to be applied to the current norm, it would be possible to project design more efficient buildings in the field of seismic resistance.
Obsolescence
The current economic and political state leads to the use of obsolete materials and construction techniques, not allowing professionals or workers to be constantly up-to-date and improving their construction methods through time.
This causes damage, especially to technologies such as seismic isolation and power energy dissipation systems.
This also stops contemporary materials from being imported or produced in the country, which usually have better seismic behavior.
Culture
when compared to other countries in the area, such as Chile, Venezuelan culture is extremely poor when it comes to the influence that seismicity has (or should have) on their lifestyle.
Even though most of the country is a seismic zone, it’s usual to find people not knowing what to do in the middle of a seismic event. Of course, this reflects on the architecture field, showing low interest in ensuring the building’s safety in these scenarios.
Teaching of Architecture in Venezuela
Taking a look at the presence of earthquake-resistant architecture or design as part of the syllabi of the biggest universities in the country, it's not hard to notice how poor it is.
Most national universities include it as part of other classes (such as structures) or as an elective class, but not as a mandatory class.
Considering seismicity across the Venezuelan territory, the importance that universities give to preparing architects for this subject is well below expected.
Presence of “Seismic-resistant Architecture” as a class in the program of some Venezuelan Universities. Source: Author
Changing the construction methods in a country demands a great effort because it implies:
☑ Reforming substantially the architecture school program;
☑ Investing in the import and production of technology and materials;
☑ Updating design and construction regulations;
☑ Changing Venezuelan’s mentality and education;
To the Venezuelan Architecture student, it's hard to incorporate automatically seismic-resistant criteria to their projects.
They are either not included in a relevant way inside the academic structure; or it’s not important to the Venezuelan’s general culture. On top of this, there is a low variety of materials on the market and labor with obsolete knowledge.
Therefore, it's up to the student’s own interest (and its teachers) to achieve projects with optimal design and create spaces that are aesthetically attractive, functional and, above everything else, safe for human use.
