Effects of Soil-Structure Interaction on Optimum Topology of Steel Bracing Systems

Making engineering judgments requires accurate modeling of the whole system. One inevitable medium in most civil engineering systems is the soil. Soil-structure interaction (SSI) has proven to be effective on numerous aspects of matters that regard structural engineering, especially when it comes to dynamic loads. This study presents how the underlying soil can manipulate the optimum topology of steel braces in steel frames. The bracing systems of the frames have already been optimized considering the structures to be fixed-base. Herein, the subsoil is modelled with potentially non-linear springs on which rest the structures’ foundations. The bracing systems are optimized once more considering the strain energy criteria and variations of the braces with regard to foundation flexibility are observed. SSI apparently affects the upper stories causing them to be more vulnerable and suggesting required bracing needed closer to the roof.

Keywords:

topology optimization , braced steel frame , strain energy density , soil-structure interaction