Experimental Assessment of the Re-Centring Capability of Curved Sliding Bearings in Shake Table Tests

The re-centring capability of isolation systems with curved sliding bearings is investigated in shake table tests carried out on a 1-story steel frame with rectangular plan, scaled at one third-length scale and isolated with four bearings. The coefficient of friction of the bearings is varied by changing the material or lubrication condition of the pads, and the response is assessed under different sequences of ground motion waveforms in terms of residual displacement after the ground motion and accrual of displacements after a series of identical earthquakes. Current code re-centering provisions are finally checked against the experimental data.