ارزیابی ساختمان پس از زلزله با استفاده از منطق فازی Post-earthquake assessment of buildings damage using fuzzy logic

1. Introduction Earthquakes are one of the most natural destructive phenomena. They have repeatedly caused considerable losses and casualties in many parts around the world [1]. The frequent occurrence of earthquakes and their consequences in terms of losses got the attention of public authorities of many countries, leading to the development and regularly update their seismic design code to better enhance the performance of buildings during earthquakes. However, numerous buildings have been built with obsolete seismic codes or even without applying any seismic codes and these buildings are mostly more vulnerable to earthquakes and experience more damage. After an earthquake, experts are deployed for post-earthquake damage survey to assess the incurred damage. One of the main objectives of the assessment tasks is the evaluation and the classification of buildings into different categories with respect to their damage levels. Many damaged buildings are sensitive and hazardous, especially when an aftershock ground shaking occurs. The unsafe buildings must be marked to be evacuated and restricted from occupancy. This classification helps to decide which buildings are safe to occupy, which need more detailed evaluations for reparation and retrofitting purposes, and which are condemned to demolition. Affected and potentially damaged buildings are usually classified using global damage levels. Global levels are determined according to the observed damage on each of the buildings’ components. These components are generally divided into two main categories, i.e. “Structural components” (columns, beams, walls, slabs, etc.) and “Nonstructural components” (staircases, separation walls, facade, balconies, etc.). The structural components are the most important part, from the mechanical point of view, as they provide the bearing capacity to the horizontal and vertical loads which refer directly to the stability and the safety of the building. The lack of resistance in these components increases the potential collapse of the building. On the other hand, non-structural components are not less important, since severe damage in these components refers sometimes to the fact that the building’s seismic capacity is decreased. Furthermore, the non-structural components ensure the usability of the building and their cost represents the majority of the building’s worth [2–4]. Multiple other hazards like soil condition around the building are also involved during the assessment procedures in different guidelines [2,5].