Experimental seismic performance of a base-isolated building with displacement limiters

Abstract

The base displacement of isolated structures may exceed its design limit, resulting in pounding with moat walls or adjacent buildings that leads to structural and nonstructural damage. This study investigates the feasibility and effectiveness of applying displacement limiting devices (i.e., limiters), with soft or hard impact mechanisms, to base-isolated buildings. Extensive shake table tests are performed on a base-isolated three-dimensional building with eight types of soft and rigid limiters. The test setup consists of a one-sixth scale three-story steel moment-resisting frame isolated at the base with laminated rubber bearings. The main input parameters are limiter stiffness, reserved gap size, and ground motion (GM) characteristics, while the main output parameters are the base displacement and dynamic response of the superstructure. The test results indicate that a proper combination of a soft limiter stiffness and the reserved gap can effectively limit the isolated base displacement response, without substantial adverse reactions to the superstructure. Rigid limiters shall be avoided since they can significantly increase inter-story drifts and superstructure accelerations under the maximum considered earthquakes.