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!
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.
- 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.
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…
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.
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.
Youtube link: https://www.youtube.com/watch?v=dzx3qOZCWIw .
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