Displacement Control Device for Base-Isolated Bridges

An isolation system consisting of sliding Teflon bearings and displacement control devices is described for the seismic protection of bridges. The system utilizes multidirectional Teflon bearings for accommodating thermal movements and for providing the isolation mechanism and displacement control devices which exhibit bilinear behavior with controlled stiffness and characteristic strength. The devices provide rigidity for service loads below their characteristic strength and restoring force and energy dissipation for strong earthquake forces.