Performance of structures in İzmir after the Samos island earthquake

Abstract

The October 30, 2020 Earthquake caused unexpectedly significant damage in İzmir considering its distance to the city. This paper evaluates the recorded ground motions, summarizes the performance of structures affected from the earthquake with emphasis on the reasons of damage. A detailed damage assessment was carried out by the Earthquake Engineering Research Center of Middle East Technical University to compile data on the damage of RC and masonry buildings. It was observed that majority of the damage was concentrated in the Bayraklı district due to its peculiar soil properties where many 7–10 story mid-rise RC buildings suffered heavy damage and collapse. The level of amplified ground motions combined with deficiencies of apparently non-code compliant buildings exacerbated the damage. The main reasons of damage were mainly attributed to the presence of soft stories, lack of proper detailing, poor construction quality, presence of heavy overhangs, and hence significant lack of code-compliance in essence. The influence of infill walls on seismic performance of deficient and inadequate buildings was clearly seen in this earthquake. This paper also discusses seismic code requirements in effect and their influence on the observed building performance. The recorded ground motions were compared with the code spectra to evaluate the performance of the buildings. The code response spectra were found to be well above the recorded ground motion spectra at the sites where significant damage was observed.

Response Spectra-Based Post-Earthquake Rapid Structural Damage Estimation Approach Aided with Remote Sensing Data: 2020 Samos Earthquake

“…Without building inventory data or calculations, the collapsed and severely damaged reinforced concrete buildings' (7-10 floors) period range was considered between 0.60 and 1.50 s in some reports and papers published after the earthquake [2,37,44], assuming that the building damages correlated with the second and third peaks of station #3513's elastic response spectra (Figure 7). However, in this study, the building heights were calculated by implementing Equation ( 5) over the satellite images using remote sensing techniques.…”

“…The majority of the damages were located in the Bayrakli region because of amplified ground motion, despite the long distance from the source [1] The presence of soft stories, lack of proper detailing, poor construction quality, the presence of heavy overhangs, and lack of code compliance were attributed as the primary causes of damage. The earthquake also demonstrated the effect of infill walls on the seismic performance of deficient and inadequate buildings [2].…”

Emergency response, intervention, and societal recovery in Greece and Turkey after the 30th October 2020, MW = 7.0, Samos (Aegean Sea) earthquake

“…Their efforts continued uninterruptedly for 6 days, until November 4, 2020, mostly focusinmg on the 17 collapsed to heavily damaged buildings. It is noted that 12 of the buildings suffered an immediate collapse (Yakut et al 2021a , b ) and SAR teams successfully recovered 107 alive residents (Fig. 4 b–f) as officially announced by AFAD.…”

“…As of 20 November 2020, it was reported by Yakut et al ( 2021a , b ), 8037 buildings suffered different levels of damage (from minor to severe) in İzmir. More precisely, 666 of them were reported to be severely damaged, collapsed, or classified as to be urgently demolished which corresponds to nearly 1.2% of the buildings in İzmir.…”

Elasto-acoustic modelling and simulation for the seismic response of structures: The case of the Tahtalı dam in the 2020 İzmir earthquake

“…The mainshock was well recorded by the broadband seismic networks of Greece and Turkey, and 35 records are located within 100 km distance from the epicenter [22,23,27,63,88]. Between October 31st and November 6th a group of engineers assembled by the İzmir Regional Directorate of State Hydraulic Works (DSI) and a reconnaissance team from METU visited dam sites to document the performance of earth-fill and rock-fill dams shaken by the event.…”