Effect of Outrigger Panels on Seismic Performance of Steel Plate Shear Wall Structural System

Abstract

Structural systems with steel plate shear wall (SPSW) have been used in many tall buildings in the past decades. This system is particularly suitable for seismic regions because it can dissipate the seismic energy through the inelastic response of steel plate in shear. However, the relatively low lateral stiffness of the SPSW structural system in tall and slender buildings may result in excessive lateral drift and high seismic demands on vertical boundary elements (VBE). Placement of additional SPSW panels in the structure acting as outriggers could significantly reduce the lateral drifts and seismic demand on the VBEs by redistributing some of the overturning forces to adjacent columns. In this paper, a 40-story building is evaluated using steel plate shear wall structural system with and without outriggers. The outrigger panels are placed in 20th, 30th, and 40th story levels and the effectiveness of these elements on the overall seismic behavior is studied. Seven nonlinear time history analyses are carried out and the seismic performance of the structural system with outriggers is compared to the performance of the system without outriggers. The results indicate a significant reduction in lateral drifts and VBE seismic demands when the system is augmented with steel plate outrigger panels.