Research On Dynamic Response Of Two-seat Series Cable-stayed Bridge Under Support Of Soft Soil Foundation

In the past two decades,the cable-stayed bridges in China have developed rapidly.The span of the cable-stayed bridges has continuously set a new world record,and the structure types are diverse.Cable-stayed bridges have extraordinary traffic significance,and usually have huge investment.If they are damaged,they will bring huge losses.In view of this,the seismic analysis of cable-stayed bridges is a long-term concern of researchers all over the world.In this paper,the current research on seismic analysis and soil-structure interaction of long-span cable-stayed bridges is summarized,and the main methods of seismic analysis of bridges and their respective application scopes are introduced in detail.Using the finite element software ABAQUS to establish a finite element simplified model considering the soil-structure interaction and the soil-structure interaction without considering,the comparative analysis of the dynamic characteristics of the two is carried out.According to the characteristics of the structure and the requirements of the calculation results,this paper selects the time-history analysis method and considers the geometric nonlinearity and material nonlinearity of the structure to analyze the structure.Using reasonable seismic waves,the seismic response time-history analysis of the two models is carried out with transverse direction +0.65 vertical and longitudinal direction +0.65 vertical uniform excitation.The pile-soil-structure interaction is discussed on the large-span two-seat on the soft soil foundation.The effect of seismic response of a series cable-stayed bridge.On the basis of the pile-free model,the connection mode between the main beam and the pier is changed,and the lead-core rubber isolation bearing is used,and the seismic response time history analysis under the longitudinal direction +0.65 vertical uniform excitation is also performed.The influence of the isolation bearing on the seismic response of the cable-stayed bridge is analyzed.Finally,because the traveling wave effect of seismic waves will also have a certain impact on the seismic response of cable-stayed bridges,this paper selects the appropriate apparent wave velocity and observes the structural response at different apparent wave velocities.According to the calculation results,it can be seen that the response of the cable-stayed bridge considering the soil-structure interaction basically has a certain increase.According to this result,the design of the bridge will be safer;and the isolation bearing is in the longitudinal direction + 0.65 vertical uniform excitation has obvious isolation effect on the cable-stayed bridge,and the internal force response of the main tower is greatly reduced,but the top displacement is also amplified at the same time.Therefore,when the lead rubber isolation bearing is used,appropriate measures should be taken.Constraining the displacement of the superstructure;the cable-stayed bridge has a large increase in the response of the main tower of the bridge at a visual wave velocity of 110 m/s,while the wave velocity of the seismic wave on the soft soil is inherently low,so it is considered to some extent.The traveling wave effect is unfavorable for earthquake resistance of bridges.