A seismic isolation bearing assembly includes a frame unit including upper and lower frames and defining a plurality of upper and lower sub-frames, and a plurality of bearing units, each of which is mounted in a mounting cell defined by a respective one of the upper sub-frames and a respective one of the lower sub-frames, and each of which includes spaced apart upper and lower load plates and a bearing interposed between and in sliding contact with the upper and lower load plates. The upper load plate is secured to the respective one of the upper sub-frames. The lower load plate is secured to the respective one of the lower sub-frames.