BRIDGE ISOLATION - A FURTHER TECHNICAL INNOVATION

JARRET has studied and manufactured pressure spring dampers devices for more than 35 years. These devices use the rheological properties, these are the properties of a fluid when it flows, of a silicon fluid. The compressibility of the fluid is used for the spring function (absorption and restitution of the energy) and the viscosity of the fluid is used for the damping function (dissipation of the energy). The applicabilities of these devices are varied, with applications in many fields, such as civil engineering, the iron and steel industry, mechanical handling, military, nuclear and railway sectors. The first applications intended for the protection of bridges and structures, using the JARRET technology, were carried out in Italy in the mid-Eighties. Since then, the number of applications have multiplied all around the world. The objective of this article is to demonstrate how tructures Bridge Isolation is a further technical innovation that has practical (and cost-effective) solutions and benefits, when compared to the traditional way of protecting bridges and structures. This paper describes the behavioural laws of the main current devices used for seismic protection, while relating them to one of the principal recent achievements, in terms of size, namely, the viaduct of Saint Andre. For the covering abstract see ITRD E106406.