BASE ISOLATED STRUCTURES WITH ACTIVE CONTROL.

Modern methods of earthquake protection for buildings and other structures have been developed in recent years. According to these methods, a soft medium is placed between the foundation of buildings and ground, and it has the role of decoupling the horizontal effects of an earthquake from the vertical load transfer. The first proposed technique suggests the use of tendons operating at the level of the isolating medium and is aimed to prevent excessive displacements of the foundation and of the structure. The second approach addresses the interstory displacements and accelerations. Using diagonal prestressing tendons at each or several stories in a building, the relative displacements and absolute accelerations are reduced.