endurance time (et) method is a relatively new performance-based earthquake method for structural evaluation and design. in this method, the structure is subjected to a gradually intensifying accelorogram(s) and its performance is assessed based on the maximum time duration that it can meet the specified performance objectives. using moment-resisting and braced frames which are rehabilitated by...

The base isolation systems are among the passive control devices that have been used over the last three decades to limit the seismic-induced response of structures. In this regard, the Uniform Building Code provisions (UBC) has incorporated a special section for the seismic design of base isolated structures since its 1991 edition. Due to the importance of the behavior of these structures unde...

The base isolation systems are among the passive control devices that have been used over the last three decades to limit the seismic-induced response of structures. In this regard, the Uniform Building Code provisions (UBC) has incorporated a special section for the seismic design of base isolated structures since its 1991 edition. Due to the importance of the behavior of these structures unde...

A ‘‘smart’’ base isolation strategy is proposed and shown to effectively protect structures against extreme earthquakes without sacrificing performance during the more frequent, moderate seismic events. The proposed smart base isolation system is composed of conventional low-damping elastomeric bearings and ‘‘smart’’ controllable ~semiactive! dampers, such as magnetorheological fluid dampers. T...

the base isolation systems are among the passive control devices that have been used over the last three decades to limit the seismic-induced response of structures. in this regard, the uniform building code provisions (ubc) has incorporated a special section for the seismic design of base isolated structures since its 1991 edition. due to the importance of the behavior of these structures unde...

One of the most successful means of protecting structures against severe seismic events is base isolation. However, optimal design of base isolation systems depends on the magnitude of the design level earthquake that is considered. The features of an isolation system designed for an El Centro-type earthquake typically will not be optimal for a Northridge-type earthquake and vice versa. To be e...

In order to improve the effect of isolation structure, the principles and behaviours of the base-isolation system are studied, and the types and characteristics of the base-isolation are also discussed. Compared to the traditional aseismatic structures, the base isolation structures decrease the seismic response obviously: the total structural aseismatic value decreases to 1/4-1/32 and the seis...

In this paper, structural nonlinear vibration control using base isolation system is studied. A nonlinear structure model with base isolation devices is developed to analyze the control effect of base isolated structure. A bi-linear hysteresis model is incorporated into the structure to mimic nonlinear behaviors. Simulation is made on this nonlinear structure with base isolation system. It can ...