In this study, sensitivity analysis of the seismic behavior of the isolated building structures in relation to the mechanical parameters of the lead rubber bearing seismic isolation (LRB) system was evaluated. The nonlinear behavior of the LRB isolator was simulated by a bilinear hysteresis model. Also, the nonlinear time history dynamic analysis method was used to analyze the isolated structures. The design optimization problem of the LRB isolator was solved using the grasshopper optimization algorithm (GOA). The results of sensitivity analysis on the seismic behavior of isolated structures with LRB show that the parameter of base shear yield ratio is the most effective and the mass irregularity is the least effective parameter on the seismic behavior of isolated structures.
