Seismic Effectiveness of Integrated Redesign of Structures Considering Soil- Structure Interaction

Previous research has shown the effectiveness of integrated redesign of civil engineering structures with control systems. A procedure for design of controlled structural systems was developed using a two-stage approach: (1) a design of an optimal control system using a Linear Quadratic Regulator (LQR) algorithm and (2) a redesign using an optimization procedure to match the performance of the controlled system obtained in (1). However past research was applied to fixed based structures considering relatively stiff soil conditions. It has been suspected, though, that using such techniques in soft soil sites while considering soil structure interaction, may diminish some of the advantages observed in past research. This paper examines the effect of soil-structure interaction on the seismic performance of integrated redesign. A linear SDOF steel portal frame, a 6 story building and a linear 9-DOF shear-type structure with different soil types and with a rigid surface foundation have been considered analyzing soil-structure interaction effects.