NEHRP Clearinghouse
- Title
- Base Isolation of a Multi-Story Building under a Harmonic Ground Motion: A Comparison of Performances of Various Systems.
- File
- PB89122238.pdf
- Author(s)
- Fan, F. G.; Ahmadi, G.; Tadjbakhsh, I. G.
- Source
- National Center for Earthquake Engineering Research, Buffalo, NY.; National Science Foundation, Washington, DC., May 18, 1988, 116 p.
- Abstract
- Performance of several leading base isolation devices for a multi-story building subject to a horizontal harmonic ground motion are studied. The responses of the structure with different base isolation systems under various conditions are analyzed. The peak absolute acceleration, the maximum structural deflection, and the peak base displacement responses are obtained. A series of sensitivity analyses is also carried out. The effectiveness of various base isolators are studied and advantages and disadvantages of different systems are discussed. The results show that the base isolation devices effectively reduce the column stresses and the acceleration transmitted to the superstructure. When the intensity of ground excitation is doubled, the peak responses of the frictional system increase by only about 10% to 25%. It is also observed that small variations in friction coefficient lead to slight changes in the peak responses of frictional isolators. Furthermore, the velocity-dependence of friction coefficient, variations of mass ratio, and damping ratio of the isolator have negligible effects on peak responses of the base isolated structure.
- Keywords
- ; Earthquake resistant structures; Vibration; Mechanical hysteresis; Damping; Graphs (Charts); Dynamic response; Ground motion; Harmonic analysis; Friction factor; Excitation; Loads (Forces); Seismic effects; Mechanical properties; Dynamic structural analysis