THE EFFECT OF SITE SOIL ON SEISMIC PERFORMANCE OF STEEL DAMPED STRUCTURE AT CLOSE DISTANCE OF ACTIVE FAULT

The geological characteristics of soil materials beneath a site have a significant impact on seismic motion and therefore, affect the seismic performance of the structures. With the aim to reduce the inelastic demand triggered by structural members of frame building during seismic excitations, one of the innovative cost-efficient solutions is theapplication of friction dampers. However, this type of dampers depend on the story displacements (story drift ratios), and they can be affected by the variation in site properties. Here, the seismic performance of a 10-story intermediate steel damped moment frame is studied under simulated near-fault ground motions for different soil types. Three strong pulselike records on the bedrock are passed through different soil layers with a linear behavior. Series of nonlinear time-history analyses under simulated records are used to investigate the effect of soil type on seismic performance of structures with friction dampers. The result indicates site soil effect rises input energy to structure; however, dampers are still able to dissipate larger input energy and keep structural elements in the linear stage. Further, soil site effect increases the maximum displacement of structure because it increases the record amplitude

Keywords:

Site Effects , Friction Damper , Steel Moment Frame , Hysteresis Loops , Near Fault Earthquakes