Abstract
This paper presents the probabilistic generation of collapse fragility curves for evaluating the performance of 3D, reinforced concrete (RC) moment-resisting building models, considering soil-structure interaction (SSI) by concentration on seismic uncertainties. It considers collapse as the loss of lateral load-resisting capacity of the building structures due to severe ground shaking and consequent large interstory drifts intensified by P-Δ effects as well as the strength and stiffness deterioration of their lateral load carrying systems. The estimation of the collapse performance of structures requires the relation between the intensity measure (IM) and the probability of collapse that is determined using the generated collapse fragility curves. Considering a number of 6-, 12-, and 18-story, 3D, RC moment-resisting buildings, two scalar IMs are employed to estimate their collapse fragility curve. On the other hand, the effect of the site soil type on the collapse fragility curves was taken into account by considering the soil-structure interaction. According to the obtained results, adopting the average of spectral acceleration (Saavg) intensity measure is more efficient in capturing the effect of the inherent uncertainties of the strong ground motions on the structural response parameters. In addition, considering the SSI for soil type D with shear-wave velocity of 180 m/s to 360 m/s reduces the median of intensity measure (IM = Sa(T1)) of fragility curve in 6-, 12-, and 18-story buildings by 4.92%, 22.26%, and 23.03%, respectively.
Highlights
According to a conventional definition, the collapse of buildings during or within short time after earthquake excitation is due to the loss of their structural system integrity that in turn is caused by generation of large deformation or force demands in their primary structural components
Assuming nonlinear behavior for steel and concrete materials and a two-way eccentricity of mass center, corresponding to 5% of the building dimension at every side, this study modeled three 6, 12, and 18-story reinforced concrete (RC) moment-resisting buildings
This is because it considers the effects of high modes on dynamic behavior of inelastic structural system as well as the effect of system response on nonlinear region, which is accompanied with increased effective period of the damaged system
Summary
According to a conventional definition, the collapse of buildings during or within short time after earthquake excitation is due to the loss of their structural system integrity that in turn is caused by generation of large deformation or force demands in their primary structural components. Current seismic design codes do not take into account duration effects and are mainly based on spectral acceleration This fact is because of the lack of actual recorded for long duration ground motion and debates about whether artificial records can take place of recorded motions. This study uses 6- and 12-story RC buildings with intermediate moment frames system as well as an 18-story RC building with special moment frame system to evaluate SSI effects on the determination of the demand and capacity of collapse and to determine the structural fragility curves. By studying the dispersion of IDA curves and the extent of the results dependency on seismic records properties the appropriate IM will be selected among two mentioned scalar IMs. Soil-structure interaction (SSI) can alter the performance of structure totally including its dynamic characteristics, response maxima, and, more importantly, distribution of nonlinear response through structure where the accurate calculation of it is vital for the performance evaluation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
