12/6/2012 Seismic Isolation Hardware-Sliding Seismic Isolation Hardware-Sliding ed res Seismic Isolation Hardware Theory of Seismic Isolation ned with othe Theory of Seismic Isolation Theory of Seismic Isolation to-w 05d 00 412/6/2012 4 Course Seminar, Tongji University, December 12, 2012 • Variations of the Friction Pendulum Bearing • Double Pendulum to increase displacement capacity • Triple Pendulum shown below is the more popular option because its compact and behavior can be controlled for different displacement amplitudes Seismic Isolation Hardware - Sliding Course Seminar, Tongji University, December 12, 2012 Single Triple Area of loop amplitude dependent Area of loop constant • Comparison of idealized response between Single and Triple Pendulum bearings Seismic Isolation Hardware - Sliding Course Seminar, Tongji University, December 12, 2012 • Seismic isolation bearings often combined with other systems such as steel dampers Seismic Isolation Hardware Photo by G. Mosqueda Course Seminar, Tongji University, December 12, 2012 Theory of Seismic Isolation • Consider single story flexible structure supported on seismic isolators • Assume isolation system is linear (spring and damper) u: absolute displ. v: relative displ. (deformations) (Christopoulos and Filiatrault 2006) Course Seminar, Tongji University, December 12, 2012 Theory of Seismic Isolation • Express equation of motion in terms of relative displacements • In matrix form: (Christopoulos and Filiatrault 2006) Course Seminar, Tongji University, December 12, 2012 Theory of Seismic Isolation • Define some parameters and estimates of magnitudes 0.5<<1 ~0.05 (Christopoulos and Filiatrault 2006)