Determination of earthquake risk situations of buildings with fuzzy logic approach

In this study, the use of the Fuzzy Analytical Hierarchy Process (BAHP) method, created by the integration of fuzzy logic and the Analytic Hierarchy Process (AHP), in determining the earthquake risk status of buildings, and the advantages of this method over traditional methods are emphasized. It has been stated that classical methods may have sharp boundaries and distinct transitions, which may make it difficult to fully address uncertainties and complexity. Fuzzy logic is very effective in expressing uncertainty and blurriness in human judgment. While traditional logic generally uses clear statements such as certain or not, true or false, fuzzy logic expresses ranges of uncertainty and produces a result closer to the human way of thinking. Analytical Hierarchy Process is a multi-criteria decision-making method used to score and prioritize different parameters. This method, when combined with fuzzy logic, allows a more flexible evaluation of the earthquake risk status of buildings. What is important is the applicability and real-life effectiveness of such a method. How useful the results obtained are in practice and how much advantage they provide over traditional methods are of vital importance, especially in risky situations such as earthquakes. Such studies help develop more robust and more appropriate solutions to human needs by showing the advantages and weaknesses of a particular method over others. P25 method is a method used for the earthquake risk assessment of buildings. In this method, 25 parameters are used to determine the earthquake loads of buildings and to perform performance analyses. In this study, the 25 parameters used in the P25 method are grouped into 5 main categories. These main criteria and sub-criteria are as follows: K1 Irregularity Factors in Buildings: Torsional irregularity, floor diaphragm irregularity, structural irregularity, soft/weak storey K2 Structural Correction Factors: Mass irregularity, short column, hanging floor factor, weak column, transverse reinforcement spacing, structural importance category, foundation type, foundation depth K3 Foundation and Soil Factors: Seismic Zone, soil type, soil settlement, soil liquefaction, landslide, soil amplification, topographic effect, groundwater level K4 Material Factors: Corrosion, concrete quality K5 Non-structural Factors: Heavy façade elements, probability of collision, level difference/partial basement In the P25 method, it is seen that irregularity factors in the structure (K1) have an effect of 16.56%, structural factors (K2) have an effect of 33.45%, foundation and soil factors (K3) have an effect of 30.19%, material factors (K4) have an effect of 7.45% and non-structural factors (K5) have an effect of 12.36% on building risk assessment. With the Fuzzy Analytic Hierarchy Process (FAHP) method, it has been determined that the impact levels of these 5 main factors in determining the building risk conditions are 29.22% for irregularity factors in the structure (K1), 34.57% for structural factors (K2), 15.82% for foundation and soil factors (K3), 10.87% for material factors (K4), and 9.52% for non-structural factors (K5) in the study. The FAHP method is a usable method for determining the earthquake risk conditions of buildings and can be further developed with more detailed studies for each sub-factor. This method can help evaluate the earthquake resistance of buildings, identify risky situations, and take necessary precautions. Keywords: Earthquake, Analysis of Buildings, Building Risk Status, Fuzzy Logic