Predictive equations for drift ratio and damage assessment of RC shear walls using surface crack patterns

The purpose of this paper is to quantify the extent of damage of rectangular reinforced concrete shear walls after an earthquake using surface crack patterns. One of the most important tasks after an earthquake is to assess the safety and classify the performance level of buildings. This assessment is usually performed by visual inspection that is prone to significant errors. In this research, an extensive database on the images of damaged rectangular reinforced concrete shear walls is collected from the literature. This database includes more than 200 images from experimental quasi-static cyclic tests. Using the concept of fractal geometry, several probabilistic models are developed by extracting and regenerating the surface crack patterns of the collected walls. These models can estimate the peak drift ratio that the structure has experienced. The peak drift ratio predicted by the proposed models of this paper can be used to calculate the probability of exceedance of different damage states using existing fragility models. Furthermore, new fragility models are directly developed using the images of the damaged walls of the collected database. The proposed fragility curves calculate the probability of exceedance of damage states using the crack pattern of the damaged shear walls and consequently provide an estimation of the loss, repair cost, and repair time of the walls.