Visual Rating Method for Seismic Vulnerability Assessment of Unreinforced Masonry Buildings

Abstract The Visual Rating Method (VRM) offers a cost-effective and rapid means of assessing the seismic vulnerability of unreinforced masonry (URM) structures, aiding in timely decision-making for retrofitting or demolition. Its simplicity and reliance on visual observations make it accessible for initial screening, helping prioritize interventions and raise public awareness about seismic risks associated with URM buildings. This research addresses the pressing need for enhancing the seismic resilience of vulnerable buildings in earthquake prone areas, focusing on URM buildings. The study introduces a systematic visual screening method as an essential initial step in the comprehensive seismic evaluation of URM buildings. A Visual Rating (VR) approach is developed, considering the specific construction materials and practices associated with URM buildings. This method aids in establishing a priority list for identifying URM buildings that require in-depth seismic assessments. By assessing the seismic capacity of each load-bearing masonry wall at different levels within a building, a visual rating index is generated. Various critical factors, including building type, number of stories, aspect ratio, slenderness ratio of walls, opening dimensions, irregularities, pounding effect, construction age, and the physical condition of URM buildings, are meticulously considered within this developed method. To validate the efficacy of the approach, existing guidelines are considered and detailed seismic evaluations are conducted on multiple URM buildings to compare seismic index respect to visual rating index. The analytical results demonstrate that this method can serve as an efficient and pragmatic tool for expeditiously assessing a large inventory of masonry buildings in seismic-prone regions. It assists in prioritizing URM buildings for subsequent, detailed seismic evaluations while optimizing the allocation of limited resources.