Proceedings of the 2 nd Croatian Conference on Earthquake Engineering - 2CroCEE Zagreb, Croatia - March 22 to 24, 2023 Copyright © 2023 CroCEE DOI: https://doi.org/10.5592/CO/2CroCEE.2023.106 MOST AFFECTED TYPOLOGIES FROM THE 26 NOVEMBER 2019 EARTHQUAKE Markel Baballëku (1) , Rikard Luka (2) , Klajdi Shaholli (3) (1) Civil Engineering Faculty, Polytechnic University of Tirana, Albania; e-mail: markel.baballeku@fin.edu.al (2) Civil Engineering Faculty, Polytechnic University of Tirana, Albania; e-mail: rikard.luka@fin.edu.al (3) Civil Engineering Faculty, Polytechnic University of Tirana, Albania; E-mail: klajdi.shaholli@fin.edu.al Abstract Assessing and finding the causes of damages in buildings belonging to construction typologies severely damaged as a result of the 26 November 2019 earthquake is of significant importance. Not only to better understand the causes of severe damage and the measures that should be taken specifically for these buildings, but also for planning the necessary interventions in these typified buildings typologies not only in the damaged areas but also in non-affected areas. This paper aims to carefully analyse some of the most severely damaged buildings by the earthquake, which have been associated with human casualties. Three construction typologies are considered in this paper, where two of them are design and build before the ‘90s as a typified buildings implemented in different cities, and the third one is a modification of typified RC building, constructed mainly after the ‘90s. One of the buildings build before the 90s is a masonry structure, while the others are reinforced concrete structure. Through damage and collapse mechanism assessment as well as using results of non-linear analysis, the paper attempts to highlight the primary causes of severe damage, compliance with building codes and the necessary measures that are recommended to reduce the vulnerability of these buildings Keywords: construction typology, brittle failure, soft story, shear resistance, nonlinear analysis, vulnerability 1 Introduction According to IGJEO on November 26, 2019, 03:54 local time, a Mw 6.4 earthquake occurred 16 km north of Durrës and about 35km from Tirana, in the western region of Albania, at a depth of 38 km. The event was preceded by an Mw 5.6 earthquake with approximately same epicentre which occurred on September 21, 2019, causing considerable damage, mainly non-structural, and affected roughly the same area as the November 2019 earthquake (26Nov ADE); (RPI-Nov.26, 2020). The 2019 earthquakes were recorded by several IGJEO stations and the data are provided online (IGEO, 2019). Unfortunately, the Durrës station (most important one close to the epicentre), recorded only the first 15 seconds of the main shock due to a technical issue (Duni L, Theodoulidis N, 2019). Some of the elastic response spectra, from Sept. 21 and Nov. 26, 2019 earthquakes records are presented in Fig. 1. The recorded PGA values were 0.114g and 0.194g in the Durrës station for the Sep.21 and Nov.26, 2019 earthquakes, respectively. In contrary, Sep.21, 2019 Earthquake produced higher PGA value in Tirana (0.183g) than Durrës (0.116g). The Nov.26, 2019 earthquake induced high seismic demands in flexible buildings in Durrës and Sep.21, 2019 earthquake induced high seismic demands in stiff buildings in Tirana. It should be noted that the Durrës station is located in very weak soil conditions (IGEO reported vs,30 = 202 m/s). Very close to that station (50m away), the measurements shows vs,30 less than 170 m/s and shear wave velocity decrease with depth Fig. 2, so, soil category can be classified as S1 according to the EN 1998-1:2004. The seismic event caused 51 fatalities, more than 913 injuries and up to 17,000 people were displaced. The total effect of the disaster in the three regions Durrës, Tirana and Lezha amounts to 985.1 million EUR, of which 70% belongs to housing sector. It was estimated that 18% of all housing units in the affected area required either reconstruction or rehabilitation (PDNA-A, 2020). Fatalities have been concentrated in two municipalities, Durrës and Thumana (an administrative unit of Kruja). In addition to the earthquake magnitude, the vicinity to the epicentre and the soil conditions, the fatalities happened in these areas are also closely related to the typified buildings that have suffered heavy damages and collapse from the seismic event. 868