Ground Effects on Buildings Seismically Protected with Energy Dissipating Devices (EDDs)

This paper presents a 2-D numerical study on the nonlinear seismic response of buildings directly built on the bedrock or on common ground. The buildings are equipped with two types of energy dissipators: Constant Friction Slip Braces (CFSB) and Adding Damping and Stiffness (ADAS). Three types of reinforced concrete buildings with 3, 7 and 15 stories, representatives of the short, medium and long period ranges, are considered. Dissipators are placed in steel diagonal braces in all the floors and the sliding threshold (or yielding) forces for each mechanism are taken as 100% of those generated by the equivalent static lateral forces recommended by the Uniform Building Code (UBC-91) for a ductile moment resisting frame. The input consists of two recorded earthquakes and each one is considered on the bedrock and as filtered by the ground with variable layers with different thicknesses. The responses of the buildings in the two cases are discussed and compared.