March 4 marks the 47th anniversary of one of the most devastating earthquakes in Romania's history. Approximately 35,000 homes collapsed across the country, and over 1,500 people died, most of them in Bucharest.
The earthquake of 1977 killed over 1500 people PHOTO archive The truth
In the years since the 7.4 magnitude earthquake, various myths have emerged about how to act in the event of an earthquake, but especially about buildings built after 1977 being much more resistant than anything from the period before the tragedy.
The Association of Civil Engineers and Structural Designers debunks the five most common myths when it comes to earthquakes.
“A structural design engineer is someone who makes sure we have strong and safe buildings so people can live and work in them safely.
They use math and science to make buildings resistant to various external factors, from high winds to earthquakes. A safer home means a home that is well thought out and calculated“, it is stated in a press release of the association.
Five myths about the earthquake
Here are five of the most common earthquake myths and what experts say about them.
If you stay under the beam you will be safe – False!
It was applicable to old buildings when the slabs were wooden, now they are concrete, and the beams will warp and crack first. Modern structures are designed by engineers so that the energy induced by the seismic action is distributed as evenly as possible in as many small points of the construction as possible. The goal is not to crack something major, but to have small things to repair as easily as possible at various points of the constructions.
He's been through many earthquakes, he'll be fine in the next one – False!
A structure after a major seismic action is equivalent to a structure with degradations (minor or major), which may affect to a lesser or greater extent the original designed resistance.
My building is earthquake reinforced concrete has no cracks – False!
As a rule, buildings are designed in such a way that they will have some degradation in the event of a high-intensity earthquake, regardless of the structural system…even reinforced concrete ones will suffer damage. Depending on the intensity of the seismic movements, degradations may occur, which will be manifested by cracking / cracking of structural elements in critical sections.
My building is strong, it doesn't move in an earthquake – False!
Under the effect of an earthquake, all buildings in the area of influence of the epicenter will vibrate, resting on the ground, which in turn vibrates (the source of the earthquake is the earth's crust). The buildings are designed to move during an earthquake so that they are neither very rigid, because a sudden rupture can occur, but also not very flexible because then the non-structural elements (plasterboard walls, masonry walls, windows, the part of ceilings etc). Only buildings equipped with seismic isolators are capable of ameliorating ground motions, which the occupants of the building will perceive as weaker.
(New) buildings are designed to withstand a high intensity earthquake without damage – False!
Such a construction would not be effective because it would have an extremely high cost. And then one accepts a smaller repair that occurs over a longer time frame than designing a 100% crack-proof house.
What structural engineers recommend
Experts say that building surveying and maintenance should be done periodically, usually at 1-5 year intervals, depending on the age, type and condition of the building. Including for new buildings, the follow-up over time has a continuous character, in accordance with the technical regulations in force.
At the same time, there are various normative tools that support the ranking of seismic vulnerability of buildings, including rapid assessment methods, as well as budgets for strengthening. Unfortunately, however, the ratio between energetically rehabilitated buildings (encased) and seismically reinforced buildings is 100 enveloped buildings to one consolidated one.
The first two recommendations of a structural engineer for a citizen concerned with prevention would be to carry out with the help of specialists, a seismic assessment of the home so that they have an idea of its safety level and to make an evacuation plan in case emergency, based on information from approved sources.
