Seismic control of irregular multistory buildings using active tendons considering soil–structure interaction effect: Fid-Bau Portal

Seismic control of irregular multistory buildings using active tendons considering soil–structure interaction effect

Nazarimofrad, Ebrahim / Zahrai, Seyed Mehdi

Abstract Much research has been conducted in recent decades on structural control to improve the performance of different towers and high-rise buildings against severe earthquakes and strong winds. Most studies on building vibration control have been considered just two-dimensionally using shear frame models. In reality, most of the buildings might have irregular plans and thus experience torsion when subjected to earthquakes. Such torsion would further increase the structural response. On the other hand, some buildings are located on soft soil that would trigger the soil-structure interaction (SSI) effects required to be considered for design purposes. The main dynamic behavior parameters like natural frequencies, damping ratios and mode shapes would depend on construction site conditions and thus the SSI effects must be taken into account for buildings on soft soil. In this paper, a mathematical model is developed for calculating the seismic response of an irregular multi-story building equipped with active tendons. The SSI effect is then introduced by changing structure mass, stiffness and damping matrices. The model is employed to obtain the seismic response of 10-story buildings using active tendon with LQR algorithm. The building is modeled as a structure composed of members connected by rigid floor diaphragms with three degrees of freedom at each story; i.e. lateral displacements in two perpendicular directions and a rotation with respect to a vertical axis. Results showed that active tendons have low effects on the reduction of structural response when the building has been located on soft soils.

Highlights • Eccentricities in plan caused tendons in perpendicular direction to be active during an earthquake. • Soft soil induces the active tendon produce high force to reduce structural response. • Structural response mitigation fails in the buildings located on soft soil by active tendons • Reduction of structural response is similar in all stories of buildings located on soft soil.