STRUCTURAL DAMAGES OF 1974 AND 1992 EARTHQUAKES
The intensity of this earthquake was relatively small. Mainly the old buildings suffered from this tremor. The damaged buildings were generally located on “soft” soils.
There were about 150,000 buildings of different sort in Izmir. The population of the city at those years was about 600,000. According to the official report of the Governor’s office, within the Centrum, 25 buildings received heavy, 14 buildings received moderate damages.
But at Karsiyaka when about 175,000 used to live, there were 43 buildings, which received moderate damages. The reinforced concrete with ribbed floors showed higher percentage of damages. Since this region is located on alluvium soil strata, there were considerable settlements observed.
There were diagonal cracks at the walls of houses of Alsancak district where there were quite number of semi-masonry two story houses constructed at 19 century. Izmir State Hospital constructed at 1880’s received minor damages.
Among the reinforced concrete buildings, only one, which was located at Karsiyaka, showed serious damages: A six-story reinforced concrete apartment building (Akkum Apt, located on the main street parallel to the sea at Karsiyaka District). The plan dimensions of this apartment of six stories were 25 by 30 meters. It was constructed in 1963. The damages occurred at the first floor columns.
The concrete strength was less than 10 MPa. The ties of the columns were not sufficient. This building has been repaired and retrofitted.
The upper section of the historical clock tower has been toppled down and the clock has stopped.
At the other masonry buildings around the city, there were cracks observed. One garden wall was destructed, but since the earthquake occurred at nighttime, no human casualties observed.
Some historical mosques have suffered from the earthquake. The minaret of an old mosque showed damages. The rest of the damages were cracks at the structural walls.
The earthquake occurred on 6th of November. The damaged buildings, which take place in those statistics, were the buildings, which were notified by their owners and investigated and classified by the staff of Izmir Office of the Ministry of Public Works and Settlement.
The damage classification was mainly based on the visual inspection and experience of the inspector and divided into five levels: starting with no damage, followed by slight damage, moderate damage, heavy damage and finally full collapse. No damage level meant absolutely any damage at all. Moderate damage included the cases where there is cracking of the infill walls but no damage in the structural frame, whereas cracking or yielding of the columns and cracking of the load bearing walls of masonry structures were classified as heavy damage.
For this earthquake, a negligible damage was reported for the city of Izmir including only a few moderate damage cases. On the other hand majority of heavy damage and collapse cases were concentrated in the villages to the southwest if city of Izmir. It is also worth to mention that out of three totally collapsed buildings, two were reinforced concrete and one was a masonry construction.
Data source (Country report)
1. Name: Behiye Fugen SELVITOPU
2. Organization: Director of the Construction Dept, Izmir Metropolitan Municipality
3. Course: 1998 Sm
4. Title: