Abstract: A two-stage optimization method is proposed to determine the optimum layout of isolation bearings. In the first stage, genetic optimization is performed to identify the parameters of the isolated layer. In the second stage, a linear programming method is adopted to optimize the layout of isolators. This study constructs a hybrid framework in which the nonlinear time history analyses are conducted using the software SAP2000 and the optimization is accomplished by MATLAB. The former provides the responses of isolated buildings, and the latter calculates the associated objective function and identifies the optimal design. The proposed method is demonstrated in a typical isolated building in China. Compared with the original design scheme, the horizontal damping coefficient of the isolation bearing arrangement scheme determined by this method can be reduced by about 12%, the maximum displacement of bearing can be reduced by about 21%, and the cost of the isolation layer can be increased by about 14%. It shows that the optimization result of this method is reliable and can effectively improve the design quality and efficiency of isolation engineering.

Key words: isolated structure, optimization, SAP2000 API, multiple population genetic algorithm, linear programming method