"...When you run so fast to get somewhere,
you miss half the fun of getting there..."
(David L. Weatherford - "Slow Dance")

Tuesday, 15 December 2020

Durrës Earthquake – 2019

A strong earthquake shook Albania early morning, just before 4 a.m. local time, on November 26th, 2019, killing 51 people, injuring over 3000ones, and collapsing many buildings. It was the strongest earthquake which hit Albania in more than 40 years, its deadliest earthquake in 99 years, and the world's deadliest earthquake in 2019. The earthquake had a magnitude of 6.4 Mww, according to the ANSS Comprehensive Catalog, with the epicenter located about 30 kilometers from Tirana to the Northwest. The seismologists said that the rupture plane had a dip of 23° to the east-northeast at a depth of about 16.5 km, and a displacement on this thrust fault of 0.55 m over a rupture with dimensions 22 km x 13 km. 

As the response spectra shows (in the following movie), there was a high frequency content of the seismic waves, with high values of ground accelerations, and an unexpected strong vertical motion! Consequently, the stiff buildings (low rise masonry ones – up to 4…5 floors - or RC prefab structures) were mostly damaged, but because of high levels of vertical ground accelerations, quite all weak RC columns were severely buckled, and large horizontal displacements were developed. In many cases it’s a real wonder that the buildings didn’t totally collapsed! 

The damages was mostly in the large port city of Durrës, and the villages of Kodër-Thumanë, Kavajë, Vorë, Shijak, Golem and Marikaj, which are near the epicentre of the earthquake.The European Union and countries in the region offered immediate assistance to Albania, and deployed a civil protection team to help the authorities coordinate the response and assess the damage. 

Romania sent military equipments, a team with a total of 52 IGSU firefighters, and SMURD doctors, nurses, and rescue materials, including search and rescue dogs. The State Inspectorate in Civil Engineering of Romania sent also a team of 15 quality inspectors for a fast post-seismic damage evaluation of more than 300 buildings in only 5 days. Following the rapid investigations carried out, the following situations were identified: 

- 195 buildings with slight degradations, usually of non-structural elements (partition or external walls), as well as small damages of some structural elements, but without risk of evolution towards the possible loss of local or general stability; 
- 27 buildings with significant damages of their resistance structures; 
- 64 buildings with severly damaged for which it was recommended a technical detailed investigation to decide if strengthening solutions could be applied, or if an immediate demolition in order to prevent other collateral risks is required. 

Among around 300 targets investigated, 166 buildings were considered uninhabitable. The evaluations revealed two main distinct situations: 

- buildings of classic solid brick masonry carried out during the communist regime (before 1990) totally non-recommended for areas with high frequency content of earthquakes, usually made as non infill walls (without perimetral reinforced concrete beams/pillars), where specific diagonal damages and severe fractures were observed, with or without risk of local or general loss of stability; 
- new buildings built between 1990-1998 or modified buildings (sometimes with 2 up to 4 floors above the initial ones!), mostly reinforced concrete frames, with severe damages as a result of improper design, including, in some cases, concrete and reinforcements of an extremely poor quality. 

Everyone agrees that only one life is a tragedy, but after such a terrific event to count only 51 deaths is quite a unexpected surprise! Yes, too many buildings are uninhabitable or fully structurally destroyed, but even if the structures were not properly designed, thousands of lives were saved, and this important detail is often ignored by too many blabbermouths. 

Overall, by the professional point of view, it was a fabulous experience. We expected to find somehow “classic” damages and building collapses, as we already saw after many other earthquakes, but what we discovered here confirmed theoretical hypothesis hard to be accepted even by specialists: that very low quality bricks could “work” as shock absorbers. After a total collapse of the infill walls, the dynamic characteristics of the “remained” RC frame structure has a sudden “jump outside” the response spectra, the building doesn’t collapse even it’s severely damaged, but all the lives are saved. It’s the old concept of an adaptive structure, a bit risky (if the idea has been considered in the initial design), but smart (or lucky?) and safe. Consequently, this earthquake gave us a strong reason to extend the research, and to make new experimental structural models. And we were convinced that we knew them all… 

Throughout the mission we enjoyed the direct support of the Romanian Embassy in Tirana, by His Excellency, Ambassador Dr. Mircea Perpelea, as well as the embassy staff, as well as the representative of the Parliament of Albania, Mr. Taulant Balla and of the local Albanian public authorities, directly by the mayors of the localities or by their representatives. We were also very pleased to meet many Albanians speaking a fluent Romanian language, and that they happily remembered their student years in Iaşi, and they were so proud of it: Mr. Taulant Balla and Mr. Saimir Kaçbufi studied law at “Al. I. Cuza” University of Iaşi, and Mr. Klodjan Xhexhi studied architecture at the “G.M. Cantacuzino” Faculty of Architecture of Iaşi, respectively. We were also well impressed by the accompanying staff and of the local coordinators professionalism: very young and good civil engineers, who made a great job doing a fast and correct evaluation of the most important buildings (hospitals, schools, kindergardens etc.) in less than 24 hours after the earthquake shook the region. 

By the way! Speaking of accompanying staff… One of our colleagues had a sudden medical issue, and we took him immediately at the emergency care unit of a local hospital. After a quick investigation, the doctor sent him in a small room to wait another specialist. Of course that he was not the only one patient in the emergency room, but one guy of the accompanying staff for building investigation was really worried. Because he felt somehow responsible (without any reason at all!) for what’s happened with our colleague, he hardly tried on the corridors to bring as quick as possible “the best doctor”. In all this time he spoke in very fluent Romanian, but with a strong Moldavian accent, and he continuously blamed “ the system” and the “unlucky moment” with the most exotic Romanian vocabulary. We didn’t had time to ask him when and where did he learned so many details of our language, but even if the situation was not so pinky, in the first half an hour we were very amused by his efforts. Although after a while our colleague has recovered, the Albanian guy seemed to be quite panicked, and it took a bit to calm him down, abandoning somehow our patient. Finally, everything was OK, and late in night, when we parted, the Albanian guy said: “I’m going to the church to say a pray for him!” It was really a touching moment. 

And two more things… 

As probably many people know, in Albania many households receive water only for a few hours every day. For this reason, the water is temporary stored in underground reservoirs, or in steel tanks placed on all buildings. That’s why wasting the water is at least an indecent gesture. 

We investigated also 13 schools and kindergartens, only two in a city, the other 11 ones were in small villages. All of them had toilets inside the building, with running water, even if it’s strongly restricted. This is a lesson which could not be learned by Romanian authorities after three decades of democracy! Yes, no matter how hard it hurts, everyone needs to know, because it's intolerable!

After the short meeting with Mrs. Belinda Balluku, the Albanian Minister of Infrastructure and Energy, and Mr. Luigi Di Maio, the Italian Minister of Foreign Affairs, when I crossed the small city square toward to coordination center I saw three boys between 10 and 12 years old playing a game. I remembered that exactly three bar chocolates remained in my backpack. I took them out and I gave one to each child. The last boy didn’t want to take it, and he said to me: “You already gave me one yesterday!”. And I replied: “For what you said, you deserve one more!” That is the definition of hope, and of a genuine future.

P.S. – This PowerPoint slide show was done in December 2019, and I strongly hoped since then that I will have a chance for a public presentation, but because this pandemics seems to be endless, I decided to publish it here as a short movie. And I still hope that it is not useless.

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