Seismic response characteristics of bridges using double concave friction pendulum bearings with tri-linear behavior

The friction pendulum system (FPS) is one of the most effective and frequently used seismic isolation devices. In this paper, a double concave friction pendulum system (DCFP) with tri-linear behavior is studied. The DCFP consists of two sliding surfaces with different friction coefficients and radii of curvature. The effects of DCFP systems with various friction values and restoring properties on a bridge are investigated under various earthquake excitations. Earthquake response analyses are carried out in the time domain on a simple bridge model with a DCFP system having various properties. Investigations are carried out on the reduction of the base-shear force on the bridge pier due to the DCFP. The advantages of a DCFP with tri-linear behavior are explored.