Seismic Isolation Solutions for Lightweight Buildings

Past earthquakes in different countries have produced many examples of lightweight buildings with significant drifts and subsequent damage at the first-story level. Seismic isolation systems have been proven effective in the protection of buildings against earthquakes by reducing base shears in structures. This paper presents details of different types of seismic isolation systems for lightweight buildings. They are characterized by lower lateral stiffness compared to classical elastomeric isolators. This feature enables them to be used for isolating lightweight structures. The lower lateral stiffness guarantees the attainment of longer natural periods of vibration in lightweight structures. An analytical model representative of the device is developed and used in numerical investigation. A four-story woodframe building model is used to examine its usefulness in lightweight buildings. Effectiveness of the proposed concept is demonstrated through numerical analysis.