A seismic isolation bearing comprises a lower plate, an upper plate, and a cylindrical
roller in rolling contact with an upwardly facing, bearing surface of the lower
plate and a downwardly facing surface of the upper plate. The lower plate is fixable
to a base, while the upper plate is fixable to a superstructure. One or both bearing
surfaces are sloped to form a central trough at which the cylindrical roller resides
under normal weight of the superstructure, and toward which the roller is biased
when displacement between the plates occurs. A pair of sidewall members are fixed
to the lower plate to withstand strong forces directed laterally with respect to
the isolation axis along which rolling displacement occurs, and a pair of sliding
guides carried one at each end of the roller provide dry frictional damping as
they engage an inner wall surface of a corresponding sidewall member.