Seismic Control of Large Span Cable - stayed Bridges Based on MR Dampers for Collision Effects

Research purposes: The longitudinal restraint of long - span cable - stayed bridge with floating system is weak, and its beam end will produce large longitudinal displacement and cause collision under the action of earthquake. Therefore, appropriate control measures need to be taken. Taking the main approach bridge of a long - span highway rail dual - purpose double tower cable - stayed bridge as the engineering background, aiming at the collision problem of the main approach bridge under earthquake, this paper introduces MR damper into the bridge. Through SIMULINK modeling, different control measures such as passive, semi - active and intelligent fuzzy control are adopted to study the damping control effect of MR damper in the collision problem of the main approach bridge of the cable - stayed bridge, so as to explore the best control scheme. Research conclusions:(1) By comparing the seven control strategies with the longitudinal displacement response of thestructure without control, it can be found that the damping effect of semi - active control is close to that of passive control, and the effect of fuzzy logic control is the best.(2) From the impact force response, it can be seen that the seven control strategies can reduce the number of collisions and the peak value of impact force between the main approach bridges, among which the damping effect of semi - active control and fuzzy logic control is better than that of passive control.(3) From the energy dissipation of damper, it can be seen that the energy input of fuzzy control is far less than that of passive control and semi - active control.(4) The conclusions of this paper can be used as a reference for the collision control of the main approach bridge of similar bridges. © 2023 Editorial Department of Journal of Railway Engineering Society. All rights reserved.