# A Hybrid ANN-GA Model for an Automated Rapid Vulnerability Assessment of Existing RC Buildings
## 2 Rapid Visual Screening Technique  
Conducting detailed and advanced finite element (FE) analyses to evaluate dynamic responses and seismic risk conditions of the large building stock in a vast area has a substantial computational burden and is very time-consuming. Therefore, applying a rapid, reliable, and efficient approach for a seismic vulnerability assessment of building stock, determining risk priorities, and filtering out buildings with high-risk levels for further analyses is vital for seismic risk mitigation and post-disaster crisis management plans [66]. To overcome these problems, Rapid Visual Screening (RVS), a preliminary survey to observe and record structural parameters, evaluate damage grades of buildings, and prioritize them for further comprehensive analyses, has proven to be a successful means [67; 68; 69; 70]. A performance score is assigned to a building through the survey outside or partially inside the building. Although there are many different methods, the main logic is based on obtaining the final score by taking into account the parameters that affect the seismic behaviour of the structure. Various approaches can be applied to analyse the data obtained from an RVS method for further risk prioritization and damage level classifications. A detailed review of different AI and SC techniques that have been used in the literature to conduct an RVS and damage classification of existing buildings can be found in [23]. Within the scope of this study, the 2013 Turkish Rapid Evaluation method has been taken into consideration as a rapid evaluation method for RC buildings [71]. The parametersconsidered in this research, which can be used for existing 1-7 stories RC buildings, are given below:  
* Number of stories
* Type of structural system
* Current status and apparent quality
* Soft story/weak story
* Vertical irregularity
* Heavy overhangs
* Irregularity/torsion effect in plan
* Short column effect
* Adjacent/pounding effect
* Hill/slope effect
* Seismicity of the region and local soil class  
The structural system type is one of the parameters in this research. The type of structural system directly affects the behaviour of a building under a seismic event. The inclusion of RC shear walls increases the earthquake resistance significantly compared to the pure RC frame. This study considers two types of commonly used RC structures, namely RC frame (RCF) and RC frame + shear wall (RCFW). The structural system score (YSP) is obtained depending on the structural system type of the building, and takes into account the total number of stories. There is no contribution when it is RCF, and the YSP value is taken as zero in this case. However, if it is RCFW, a positive YSP is added depending on the total number of stories. The basic logic here is based on the positive contribution of the RC shear walls to the seismic behaviour of the building. The types of structural systems considered are given in Figure 1. In order to determine whether there are RC shear walls in any building, a decision is made by entering the building and making observations. If it cannot be determined exactly whether RC shear walls exist in the building, the structural system should be considered RCF. The number of stories is the sum of all stories, including the foundation [71]. Studies conducted after previous earthquakes revealed that the damage to a building had a linear relationship with the number of stories [72]. The part with the most significant number of stories is considered in gradual structures. Figure 2 shows how to calculate the number of stories in the rapid assessment method considered in this study. Figure 1: Structural system type (**A**) RC Frame (RCF) and (**B**) RC Frame with Shear Walls (RCFW). Figure 2: Determination of the number of stories (ns). The strength of the materials that make up the building directly affects its seismic performance. The performance of workmanship and material quality during and after the construction process reveals the quality of the building [73; 74; 75].