Cost-effectiveness evaluation of MR damper system for cablestayedbridges under earthquake excitation

摘要

A method for evaluating the economic efficiency of a semi-active MR damperrnsystem for cable-stayed bridges under earthquake loadings is described. The economicrnefficiency of semi-active MR damper system is addressed by introducing the concept of a lifecyclerncost. To evaluate the expected damage cost, the probability of failure is estimated by usernof the crossing theory and simulation methods. As a measure of economic efficiency, the costeffectivenessrnindex is defined as the ratio of life-cycle costs between a bridge structure with thernMR damper system and a bridge structure with shock transmission units. In the evaluation ofrncost-effectiveness, the scale of damage cost and the scale of the MR damper cost are adopted asrnparametric variables. The results of the evaluation show that damper cost has little influence onrnthe cost-effectiveness of the MR damper system, while the scale of the damage cost has arnsignificant influence on cost-effectiveness. It is also found that the MR damper system is highlyrncost-effective especially for the ground motion in regions of moderate seismicity with soft soilrnconditions, as well as strong seismicity with stiff soil conditions.