Ebrahim NAZARIMOFRAD - Bu alisina Univ ersity, Department of Civil Engineering, Hamedan, Iran
Jalal AKBARI - Malayer Univ ersity, Department of CivilEngineering, Malayer, Iran

During the last three decad es, significant researchesin active control field have been reported. However,in most studies, for imple mentation and evaluation of active control alg orithms,the building has been considered as a two-dimensional shear frame.In reality, most of the buildings are three-dimensionand especially for asymmetrical planbuildings under earthquake; building's torsion will be induced to increasing the structural response. In this pa per, aneight- story three-dimensional buildinghas been considered as astructural model and fully active t endon controller implemented in two directions of the building. In order to reduce the seismic responses of the structure, the LQR control algorithm is u tilized. The building is modeled as a structure composed of flexural members that connected tothe rigid floor diaphragmswith three degrees of freedom at each floor, i.e., twolateral displacements and one rotation ab outthe vertical axis. The results show that by adding the tend ons in both x and y directions,the lateral displac ements andtherotational responsesaround the vertical axis w ill be reduced.

Active Control, LQR Control, Genetic Algorithm, Torsion in Asymmetric Plan