Buildings need not have us quaking, but some are built on shaky ground
To the question, «What is seismic protection?» Carydis replied: «When the building doesn’t collapse in a strong earthquake.» How great is the cost of seismic protection of a house? It’s relatively small. It corresponds to 5 percent, at most, of the total cost of construction. While if a building suffers damage, the cost of repairs can reach 100 percent of the value of a house or even cost us our lives. In the past, they used to say that concrete was a trustworthy material. Concrete is a modern material that can be cast into any shape you want. Therein lies the great challenge, the great responsibility and the great trap. It is a myth that old buildings are not safe. Quite the contrary. All buildings are safe when they are correctly designed, well built and properly maintained. Running for the roof What should we do if we find ourselves inside the house during an earthquake? We need to have chosen beforehand a safe place inside the house, and immediately afterward to climb up to the roof and not try to hit the pavement straightaway. There should be a law that enjoins emergency exits to have an opening to the roof. The rooftop should not be a place locked up by the topmost dweller of a block of flats. If this had been the case, we wouldn’t have had 42 fatalities in Thessaloniki in 1978, when the exit of a block of flats was blocked, trapping the residents. The apartment block did not collapse immediately. What are the weaknesses of the Greek construction industry? From the point of view of studies, we are excellent; Greek engineers do their job very well. But they depend on the seismic regulations in force at the time, and on the way they’re implemented. If the regulations do not have correct specifications which follow local developments, or they are not observed, it’s not the fault of the engineers, who moreover are not paid for supervision. It’s the construction phase that is beset by problems, because the owner might not choose the best builder, the materials might not be ideal. There is a tendency to make false economies. But for me the post-construction period, when additions and alterations are made, is very important. An extra story added, a wall being taken away could prove fatal. It’s very important how you maintain a building. Many of the buildings damaged by earthquakes today have not been repaired properly. In the 1999 earthquake, the competent bodies did not do their level best to get the best results. The building should not be returned to its pre-earthquake state; its seismic coefficients need to be reinforced, so that if an earthquake recurs, we don’t have the same results, or worse. Despite this, many of the studies submitted in order to obtain state funding for repairs were rejected because they provided for reinforcement – that is, they cost more. A study should have been decoupled from the amount of state subsidies. Subsidies could then have been granted on the basis of the damage that took place, regardless of how the building would be repaired and reinforced. Reinforcement should be an imperative, and not bound by the level of state subsidies, which is legitimately subject to financial considerations. It’s an important issue that will come up again in the coming years.
