Performance of Precast Wall-Slab-Wall Systems under Seismic Excitation

Precast construction shows significant growth nowadays because of its advantages over traditional cast in situ construction. There are two main types of precast systems: moment-resisting frames (MRFs) and structural wall-slab-wall (WSW) systems. Out of these two types, the WSW system has not been widely studied, especially from the point of modeling the system. The present study aims to model the precast connection for a 5-story WSW building inexpensively yet reliably. For this purpose, two types of analysis are performed: (1) slabs and walls modeled by shell elements, and (2) slabs and walls modeled by beam elements converting slabs to a grid. Both models are analyzed with and without a default plastic hinge placed on the slab at a 0.1L distance from the wall–slab interface. The precast WSW system is analyzed for specified connection behaviors expressed in terms of the moment (M)-rotation (θ) curves, and its performance is evaluated with respect to the monolithic WSW systems. Three normalized backbone curves representing the connection behavior were selected from the literature for the analysis: two for the precast model and one for the monolithic model. The nonlinear time-history analysis of the WSW system under a suit of earthquakes with different peak ground accelerations (PGAs) is carried out to obtain the response quantities of interest, which include base shear, maximum interstory drift ratio (MIDR), and maximum story displacement. The results of the study indicate that the performance of the precast WSW building is the same as that of the monolithic WSW building if the connection behaviors of both are specified. However, in most cases, the connection behavior of monolithic systems is not specified. Under those conditions, the precast WSW building shows inferior behavior compared with monolithic WSW systems.