Analysis and preliminary design of isolated bridges considering soil-structure interaction

The efficiency of base-isolated bridges and several important parameters are evaluated in this paper. A preliminary design procedure and a set of design charts that can be adopted to select quickly the isolators are suggested. The selection of the isolation system is based mainly on three considerations: 1. The efficiency of the isolation system in the protection of structures from earthquake; 2. The vertical bearing capacity of the isolators; and 3. The constraint of the displacements in the isolation structures. It is shown that the applicability of isolation systems depends on the soil condition, on the characteristics of the structures, and on the frequency of the excitation.