Abstract: The disclosed seismic isolation bearing includes an upper base plate, a lower base plate, a disc bearing core, and at least one shear spring. The upper and lower base plates each have an upper surface and a lower surface. The disc bearing core is centrally positioned with respect to the planes of the upper and lower base plates and is in contact with the lower surface of the upper base plate and the upper surface of the lower base plate, where the disc bearing core allows the lower surface of the upper base plate to slide along the disc bearing core. The shear spring is coupled to the lower surface of the upper base plate and the upper surface of the lower base plate, deforms in shear upon lateral movement of the upper base plate relative to the lower base plate, and exerts a lateral return force on the upper base plate when laterally displaced.

Abstract: The disclosed seismic isolation bearing includes an upper base plate, a lower base plate, a disc bearing core, and a shear spring surrounding the disc bearing core. Concave recesses are formed in a lower surface of the upper base plate and an upper surface of the lower base plate. The disc bearing core is centrally positioned with respect to the planes of the upper and lower base plates and can slide along the recesses of the upper and lower base plates, where the recesses exert a lateral return force on the disc bearing core when displaced from a central position. The shear spring surrounds the disc bearing core, deforms in shear upon lateral movement of the upper base plate relative to the lower base plate, and exerts a lateral return force on the upper base plate when the upper base plate is laterally displaced.

Abstract: A unitary compound earthquake isolation bearing which permits the installation of a compound bearing comprising a sliding bearing and at least one MER as a single unit without special and separate attachment of the MER to the support or superstructure.