Abstract：Floor acceleration amplification (FAA) factor is the ratio of the peak floor acceleration to the peak ground acceleration. FAA represents the amplification effect of the main structure with respect to the ground motion, and is one of the critical parameters in computation of the equivalent seismic force of the nonstructural components installed in each floor level of the main structure. Current code provisions are mostly based on the limited historical earthquake records and finite element model of simple building structures, so that they are not qualified enough to represent the actual FAA distribution profiles in various buildings. Subsequently, the computed equivalent seismic force is quite different from the actual inertia force subjected by the nonstructural component. Using the floor motion records of California Strong Motion Instrumentation Program and new building height classification standard, FAAs in concrete, steel, and masonry buildings were computed and the results show that current code provisions on the FAA cannot effectively envelop the measured ones in a reasonable extent. Parabolic curve was applied to regressing the FAA data and the corresponding parameters were provided to the concrete, steel, and masonry buildings with various height levels. Due to the whip effect, the FAA near the building roof is usually much larger than that in other stories, therefore, a supplementary FAA branch was suggested for the tall, and very tall buildings. At the end, the effect of the vibration period of the building on the FAA was considered in terms of height levels of the buildings. This study can be referred to by the coming code revisions and shall be helpful to designers and researchers.
