“Seismic reconstruction is not an exact science”

The cross :You are in Kahramanmaras, a city in eastern Turkey, hard hit by the earthquake. What situation do you see?

Patrick Coulombel : Overall, the Turks take charge. The rescuers gave way to the diggers to begin the clearing. Their logic is first to make the roads accessible. In the city center of Kahramanmaras, the main arteries are blocked by collapsed buildings. Residents come to look for goods or documents belonging to them, but also the remains of those who are still in the rubble…

According to some reports, the health situation seems quite alarming. Does it seem under control to you?

P. C. : The State is mobilized, significant resources are deployed. I did not notice any major problems, the aid is organized in a country which has organized infrastructures. International NGOs are not there yet. It’s a bit spartan, it lacks toilets, but people aren’t starving in the streets.

You should know that we are in a very particular political context: elections will take place next May and some towns are run by opposition parties. The information given is sometimes to be taken in the conditional.

11,000 buildings have collapsed, according to the government. But in a significant number of them, perhaps 20 or 30% (we have no certainty about this figure), the ground floor has been crushed by the floors above, the residents therefore being able to get out of the building without losing your life.

What feedback from the field do you get from the Turkish architects you work with?

I don’t want to speak for them, because the context is delicate. As soon as you mark any opposition, it can become very complicated very quickly. Corruption at all levels is denounced, on the sly, whether for the granting of land or the awarding of building permits.

Critics are numerous in Turkey on the lack of compliance of buildings with anti-seismic standards…

P. C. : The age of the buildings is an important point here. In the old city of Kahramanmaras, where I am, the minaret of the mosque has fallen, but the rest of the building, which is 500 years old, is intact! As there have already been earthquakes in the past, these old wooden and stone constructions have been reinforced. It is an instructive example of how buildings that remain standing should be restored. There are no seismic regulations adapted to the heritage. We can learn from it, but the constructive habits are not the same.

Of course, new buildings have collapsed, but this is, in my opinion, at the margin. The victims did not die, for the most part, in new buildings, that is not true! Those who perished were in buildings in the hypercentre, relatively tall, built in the 1960s or 1970s. They were not built according to seismic regulations, since these are more recent. As I speak to you, I am in front of ruins with heaps of scrap metal: all the steels used are smooth. However, they have been banned in construction for a long time, because they adhere less to the concrete.

How to rebuild, in which places and according to standards adapted to the damage observed?

P. C. : The reconstruction must be seismic and be done according to the rules of the art. Because, when you build quickly and hard, it costs less than going through a phase of temporary shelters that end up being permanent, as in Haiti with plywood huts.

Generally, lessons are learned in the years following a major earthquake like this to enact standards more suited to the context. Depending on the type of soil, the building is not subject to the same constraints due to seismic wave amplification phenomena. The ground can also sometimes liquefy and subside under a building. There are so many parameters that it’s not an exact science. How to explain for example that, out of three buildings built at the same time by the same contractor, two fall and not the third?

These are real worries. The Turks are going to have to do seismic reinforcement everywhere because they don’t want that to happen again. However, even in countries like Turkey, we do not necessarily do this work because it is very expensive. This is also the case in L’Aquila, in Italy, or in Nice where, despite the seismic risk prevention plan, the number of condominiums to have launched these projects should not be high…

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