Development of seismic risk models for low-rise masonry structures considering age and deterioration effects

Abstract

Many seismic damage field observations of masonry structures indicate that buildings constructed in different eras differ in terms of seismic risk and vulnerability under time-varying deterioration. However, the age deterioration effect is rarely considered in structural seismic vulnerability analysis, challenging the accuracy of the developed seismic risk model assessment. This paper considers the impact of age deterioration on seismic hazard and vulnerability, and an innovative probabilistic seismic hazard and risk model was developed. Using earthquake hazard theory and 1452,582 accelerations monitored by 11 stations during the 2008 Wenchuan earthquake in China, dynamic time history and response spectrum curves were generated considering the directionality of ground motion. Using the innovative model developed, the seismic vulnerability grade of 1228 low-rise masonry structures (Dujiangyan city) affected by the Wenchuan earthquake that the author investigated was evaluated, and a failure probability matrix of low-rise masonry structures considering the influence of age deterioration was established. A nonlinear fitting function was proposed to assess the seismic vulnerability of low-rise masonry structures, and vulnerability curves were generated via the developed empirical dataset. According to multiple onsite structural damage observations, there is a correlation between adjacent vulnerability and intensity grades. To study the correlation between the adjoining vulnerability grades of low-rise masonry structures under the influence of aging and different seismic intensity measures, an innovative structural seismic risk index model considering empirical and probabilistic algorithms (vulnerability correlation index (VCI) and intensity–vulnerability correlation index (IVCI)) has been proposed. On the basis of the seismic damage dataset, seismic risk curves for low-rise masonry structures were generated, considering the influence of age deterioration.