Base-isolated buildings: towards performance-based design

Abstract

Base-isolated buildings, founded on steel springs or elastomeric bearings, have been employed since the 1960s in locations susceptible to ground-borne vibration. Examples exist across a wide range of buildings, from residential to commercial, and include specialist buildings such as concert halls and hospitals. In all cases, the objective is to reduce internal levels of perceptible vibration and re-radiated noise, with the most common sources of concern being nearby surface or underground railways. Despite the extensive use of base isolation, there is a significant lack of guidance on all aspects of design, from the selection of bearing type and their location within a building, to questions such as how performance should be evaluated, and the most fundamental question of all: is isolation necessary? This paper reviews current practice in base-isolation design, and highlights some of the challenges and future research efforts in moving towards a performance-based design approach for controlling ground-borne vibration.