Development of seismic fragility curves for precast concrete frames with cast-in-situ concrete shear-walls

Precast reinforced concrete buildings have been well received in some seismic zones worldwide due to advantages such as the ease and the speed of implementation, and the possibility of working in inappropriate atmospheric conditions. In this research, seismic fragility curves were developed for precast concrete frames with a cast-in-situ concrete shear-wall, concerning the important issues of modeling the precast beam-column joints, construction quality, and soil type effects. For this purpose, the incremental dynamic analysis (IDA) was conducted for three-dimensional models of 3-, 5-, and 8-story buildings under two record sets corresponding to soil types C and D of the NEHRP code. Beam-column joints were modeled using nonlinear rotational springs with rigid links with respect to the finite size of the joint panel. Results demonstrate that the Weibull distribution can be fitted to the damage state capacities better than the lognormal distribution at the intensities that are more than one standard deviation away from the median damage capacity. The seismic vulnerability of precast structures increases at all damage states as the height of the building increases. It is also observed that soil type has almost no considerable effect on the fragility curve parameters for all damage states considered herein.