Abstract
This paper proposes a rational and efficient optimal design method for seismic-isolation bridge systems which consists of superstructures, seismic-isolation bearings, piers and pile foundations subject to huge earthquakes. The special characteristic values for dynamic hysteresis of seismic-isolation bearings, piers and pile foundations are dealt with as the design variables, and the estimation formulas of the maximum horizontal displacements are introduced efficiently as the functions of design variables by using the experimental design method. The proposed optimal design method is applied to construction cost minimization problems of five-span continuous steel girder bridge systems and rigorousness, efficiency of the proposed design method are clarified by investigating the optimum solutions.
