Effect of plastic zone levels on the responses of concrete shear walls
subjected to strong ground motions
Abstract
Generally, in reinforced concrete (RC) core wall buildings, the
formation of one plastic hinge at the base is preferred; this is
referred to as the Single-Plastic Hinge (SPH) approach. This paper
considers RC core walls of 30, 40 and 50-storey tall buildings, designed
using a response spectrum analysis. Then, the SPH, Dual-Plastic Hinge
(DPH), Triple-Plastic Hinge (TPH) and Extended Plastic Hinge (EPH)
approaches are examined using fibre element models and using nonlinear
time history analysis. The DPH and TPH approaches contain one and two
plastic hinges at the upper levels of the wall, respectively, in
addition to the base plastic hinge. The effect of the locations of the
upper plastic hinges on the seismic response of the core wall is
investigated. The results show that there is not a distinct level for
the upper plastic hinge location to minimize the envelope of different
demand quantities simultaneously. The curvature demand of the middle
plastic hinge in the TPH cases is higher than the base curvature
demands. Reducing the resistant moment at the wall base by reducing
reinforcement ratio can help to balance the curvature demands along the
height of the TPH model