Experimental analysis of earthquake resistant base isolated structures with hybrid spherical rollers

Abstract

A new seismic isolation bearing is designed and modernized for improving the performance of structures during seismic force. This new bearing uses Hybrid Spherical Rollers (HSR) on the concave sloping surface to achieve newlineisolation with additional shock absorbing sandwich plates surrounded by them to increase the damping of the structure. The bearing is characterized by a self centered capability. Each roller is free to displace under 3-translational and 3- rotational directions hence, it is capable of reducing the seismic response and prevents the structure from transmitting the destructive surface wave. The objective of this research is to determine the seismic behavior through newlineexperimental investigation on four models they are Fixed Frame (FF), Base Isolated Frame (BIF), Braced Frame (BF) and Infill Frame (IF). A linear harmonic shake table test is conducted to verify its dynamic characteristics and response. The experimental studies were carried out for the following parameter they are, acceleration spectra, displacement spectra, velocity spectra, story shear,and drift ratio. The comparison of experimental result with analytical findings is done for better reflection. A good correlation exists between the experimental and analytical model. The analytical result coincides with experimental values in the range of 98% for acceleration, displacement, velocity, and story shear. The results were discussed to show the improved efficiency of base isolation using the HSR isolator during earthquakes where the majority of other techniques (elastomeric bearing, friction pendulum bearing, Lead elastomeric bearing, etc.) do not perform well. newline newline