Methodology for the seismic risk assessment of low-rise school buildings in British Columbia

This thesis presents a methodology for the seismic risk assessment and risk reduction of schools in British Columbia. The methodology permits school buildings to be ranked by risk levels, and includes information that allows designers to establish the seismic capacity of school buildings and to select appropriate retrofit options. This research includes the treatment of seismic hazard in the province by reference to different types of earthquakes that affect the region, and the development of an extensive database of structural performance of typical school buildings for different types of earthquakes and levels of shaking. The seismic hazard in the province is due to crustal, subcrustal and subduction earthquakes. The ground motion characteristics and the rates of occurrences of these different types of earthquakes are sufficiently different that it justifies assessing their effects separately in the risk calculations. The results of probabilistic seismic hazard analyzes have been combined with incremental nonlinear dynamic analyzes of a variety of structural systems subjected to the three earthquake types. A suite of thirty ground motions representative of these earthquakes has been used for the calculation of seismic risk. This process resulted in a large database of response of structural systems on different types of soils. The database was developed first for systems on firm soils (Site Class C). To account for soft soils (Site Class D) a simplified procedure was developed to convert structural performance on Class C sites to that on Class D sites. This thesis presents information that contributes to the state of knowledge in seismic risk in two forms: research and engineering practice. It provides a better understanding of how the risk in a region can be deaggregated according to the earthquake types, how representative ground motions for each earthquake type can be selected, and how the site conditions can be incorporated in probabilistic risk assessment. The contribution to engineering practice is the development of a ready-to-use methodology for risk assessment and for determining whether or not a retrofit is required for a giving type of structure on a certain type of soil and in a given seismic region.Applied Science, Faculty ofCivil Engineering, Department ofGraduat