Energy-based assessment of reinforced concrete walls with two outriggers

Abstract

In this paper, different kinds of energy dissipation in reinforced concrete (RC) core–wall systems with two buckling-restrained braced outriggers, subjected to forward-directivity near-fault and ordinary far-fault earthquakes, have been compared. The level of the first outrigger was fixed at the top and the second outrigger was placed at different levels. In the non-linear model, two approaches for the RC core–wall were considered: the extended plastic hinge (EPH) approach and the four plastic hinges approach (4PH). In the 4PH approach, only four plastic hinges are allowed in the RC core–wall, one at the base, another adjacent to and beneath the top outrigger, and two others at the level's adjacent second outrigger. For the EPH approach, the plasticity can extend anywhere in the core–wall. Principally for the EPH approach, at the base of core–wall and adjacent to the top outrigger, as well as above and below the second outrigger level, more inelastic energy demands occur due to the large moment demand resulting from seismic load. On average for both EPH and 4PH approaches, the inelastic energy at the base from far-fault records is almost 1.5 times the corresponding value from near-fault records.