In practice of seismic base isolation of bridge structures, laminated rubber bearings have been popular since the last century. Several mechanisms of investigating the mechanical behavior of isolation systems are developed based on this philosophy which is readily used. The philosophy given by them regarding seismic isolation of a structure is stillin practice. What both guys wanted to get information from their experiments is the global isolation behavior of the structure. Calantarients in 1909, a medical doctor of the northern EnglishCity of Scarborough, was claimed to be the first man who conducted the experiment of isolation behavior of a structure supported by balls. Above the balls and attached to the buildings are cast-iron plates slightly concave but otherwise similar to those below”. The study on the mechanical behavior of the isolation system dates back to 1886, when Professor Milne from Tokyo University, Japan attempted to observe isolation behavior of a structure supported by balls.He conducted an experiment by making an isolated building supported on balls “ cast-iron plates with saucer-like edges on heads of piles. Until the 80 th decade of the last century many systems have been put forward involving features such as rollers or rockers bearings, sliding on sand or talc, or complaint first story column, but these have usually not employed in the practice of isolation of engineering structures. In some cases, application of base isolation can raise both a structure's seismic performance and its seismic sustainability considerably.Īn isolation system is believed to be able to support a structure while providing additional horizontal flexibility and energy dissipation. It is meant to enable building and bridge structure to survive a potentially devastating seismic impact through a proper initial design or subsequent modifications. It is a collection of structural elements which should substantially decouple a superstructure from its substructure resting on a shaking ground thus protecting building and bridge structure's integrity.Base isolation is the most powerful tool of earthquake engineering pertaining to the passive structural vibration control technologies. Base isolation, also known as seismic base isolation, is one of the most popular means of protecting a structure against earthquake forces.

Lead rubber bearing isolator