The importance of a seismic design of structures using base isolation techniques is becoming increasingly evident to architects and structural engineers. Many different types of base isolators, generally complex mechanical systems which require an extra floor beneath the building, have been proposed to date. Existing isolation systems are either of a pure-friction or flexible type, or a combination of the two. They reduce earthquake-induced lateral inertial forces on structures through limiting friction effects and/or lengthening the natural period of vibration of the total system. Frictional properties are usually provided using stacked Teflon-coated steel plates, while flexibility is provided by elastomeric rubber pads. A new base isolation system employed in the soil supporting the building foundations is proposed to be evaluated and implemented. This is a practical, low cost, and simple-to-install base isolation system which is comprised of friction and flexible type isolation materials. Soft backfill materials around the building basement will limit the lateral deflection of structures. The experimental and analytical studies proposed will test the effectiveness and efficiency of the proposed system.The potential commercial application as described by the awardee: Research will lead to an economical, easy-to-install base isolation system to be used in earthquake-resistant design of structures and in minimizing damage to contents of buildings.
