Research On The Application Of Velocity And Displacement Dampers In Seismic Engineering Of Cable-stayed Bridges

At present,the static analysis of long-span cable-stayed bridge has been relatively mature,but the dynamic analysis,such as the seismic analysis of the bridge,still needs further analysis and exploration.Earthquake,as a serious natural disaster,will bring huge economic losses once it happens.Therefore,it is very important to design effective seismic system for long-span cable-stayed bridge.Dampers are usually used in seismic design to reduce the seismic effect.Dampers can be distinguished between velocity type and displacement type.In this paper,the viscous damper of the velocity type damper is selected as the seismic device in the direction of the cable-stayed bridge.By changing the setting parameters,the seismic optimization analysis is carried out.The Cshaped steel damper and viscous damper of displacement dampers in the transverse bridge direction are compared and analyzed to analyze the characteristics of the two dampers in ground motion control.By analyzing whether the designed seismic system can meet the design requirements and studying its working performance characteristics,the design ideas with strong universality for the seismic design of long-span cablestayed Bridges are obtained.Firstly,this paper studies the four main support systems and structural characteristics of cable-stayed Bridges,analyzes the main types of damage of cablestayed Bridges under earthquake action,and sets up the preliminary seismic design ideas according to their characteristics.Four common vibration control methods of bridge structure are analyzed and studied.Finally,passive control device is adopted as the shock absorption and energy dissipation device in this paper.Secondly,the viscous damper and the C-shaped steel damper are selected as the seismic devices in this paper.The mechanical properties and structural characteristics of the two dampers are analyzed,and a specific damper is selected for mechanical performance test to verify its working performance.Taking a bridge as the example,a model is established considering the pile-soil interaction,and the dynamic analysis is carried out to analyze the speciality of the first 10 modes.The bending and shear capacity of key structures are calculated according to the code.Finally,according to the design parameters of two kinds of damping tested in this paper,Maxwell model is used to simulate viscous damper,and hysteresis system is used to simulate C-shaped steel damper.Modular design is adopted.The viscous damper is used as the seismic device in the seismic system along the bridge.A total of 5 different working conditions are set to carry out parameter optimization design.The viscous damper and the C-shaped steel damper are used as the seismic devices for the transverse bridge seismic system.The nonlinear time-history analysis method was used for analysis.Finally,it is concluded that working condition 5 is adopted in the direction of the bridge,that is,the damping coefficient at pier 1 and 4 is 1750,and the damping coefficient at pier 2 and 3 is 3500.This scheme can prevent the beam from falling under the earthquake action.The displacement control effect of C-shaped steel damper at tower 3 and pier 3 is better than that of viscous damper on the premise that the damping force generated by the transverse bridge is the same,and the displacement control effect of viscous damper at pier 1 is better than that of C-shaped steel damper.The energy dissipation effect of the viscous damper is better than that of the C-shaped steel damper.