On Dynamics of a Dual Vibration Insulation Device Based on Elastomeric Kernel and Rolling Friction Dissipation

Nowadays, there are several insulation solutions for bridges or viaducts structures that work based on various insulation principles. The basic principles used in the bridge isolation field are represented by vibration insulation and energy dissipation arising from various dynamic loads acting upon the structure, thus that the devices in use are mainly categorized as isolators or energy dissipation devices. An innovative solution for bridge isolation is described in this paper, which uses a composed system able to use both isolation and dissipation characteristics of these two devices types. It has been designed a particular device model, meaning dual vibration insulation device, which is composed of an elastomeric isolation type system, working in tandem with a dissipative device based on rolling friction. This hybrid device has been built and mounted on a bridge structure achieved on a reduced scale. Thus, the isolated structure has been tested at dynamic actions by generating vibrations within the bridge structure using a special exciting device. According with the obtained results higher acceleration values are recorded at the bridge pier support level, while they are more attenuated at the superstructure level, due to interposing of the dual vibration insulation device between the bridge pier and the superstructure. This type of composed isolation device provides additional degrees-of-freedom within the entire ensemble, thus that the bridge support pier can move along with the foundation soil, which induces the dynamic loads, while the superstructure is able to maintain a steady-state dynamic regime without being affected, in a considerable way, by ground movements. In this paper, are presented the results recorded on the experimental model at the bridge support pier and superstructure level regarding the time and the frequency evolutions of the acceleration signals.