More stories are added to a multi-storey RC frame using lead laminated rubber bearings.A program is developed with MATLAB language to conduct elastic-plastic time history analysis,according to the optimization results of lateral rigidness and damping ratio of isolation layer based on energy criterion,and two real ground motion records and a synthetic record are input.The results show that displacement and acceleration response,interstorey shear force and story drift of each storey decrease compared to those...