Principle of Elastomeric Supports as Antiseismic Isolation Systems

Abstract

Special systems have been designed to be mounted at building structures acting against the effects of ground dynamic motions caused by earthquakes. Such systems considered as isolators working on dynamic regime are based on the elastomeric supports. The elastomeric isolators are typically installed at structure base and meet the conditions of base isolation principle by interposing between the foundation and the superstructure. Achieved mainly of rubber in combination with stainless steel plates to increase the compressive strength, this type of support can ensure the limited free movement of foundation together with ground during an earthquake, materialized in horizontal displacement or rotation in the horizontal plane. This paper describes two types of elastomeric systems, the simple model, but also the lead core model, showing the hysteretic behavior for each of them. The elastomeric supports can be used for base isolation of bridge or viaduct type structures, but also low-rise buildings that are located on stiff soil. The base isolation procedure for these structural types have results in increased natural vibration period obtained together with the movement provided by the isolation system.