Seismic vulnerability and risk assessment of confined masonry dwellings in Guatemala city

When conducting a seismic risk analysis of buildings in earthquake-prone areas, it is important to consider the structural characteristics that affect their seismic performance. These are dependent on construction and design practices. This paper aims to incorporate such features in the assessment of confined masonry dwellings located in Guatemala City. These buildings are often non-engineered and built with artisanal materials whose quality is uncertified. Also, building regulations are frequently disregarded in Guatemalan housing construction. The goal of this study is to evaluate the possible consequences of earthquakes on confined masonry dwellings in Guatemala City by computing their seismic vulnerability, in the form of fragility curves; and seismic risk, measured as the annual collapse rate. The results were then contrasted with Guatemalan regulatory standards, to provide a better understanding of the current situation of this type of building. To this end, the study collected data on 28 one- and two-story dwellings located in different areas of Guatemala City. With the data obtained, the open-source software Vulnerability Modelers Toolkit (VMTK), developed by the Global Earthquake Model Foundation, GEM, was employed to compute fragility curves of the buildings. Subsequently, the annual collapse rate was calculated as the convolution of the collapse fragility curve with the seismic hazard curve of Guatemala City. The study highlights the importance of selecting seismic records that reflect the seismic environment of the region when assessing seismic vulnerability, as well as capacity and structural modeling parameters. It also shows how much the seismic risk of the types of buildings assessed could be reduced considerably if the regulatory standards currently in force in Guatemala were applied.