Study On Cable Force Of Cable Stayed Bridge Of Liaohe Bridge Based On Hralth Monitoring

In recent years,the construction of long-span cable-stayed bridges at home and abroad is increasing.The cable-stayed bridge is a bridge system,compression support system of compressed structure system,has more than span girder bridges of cable-stayed bridge,which makes the existence of more than ordinary bridges the difficulty in the design and construction process,so to determine a reasonable construction state of cable-stayed bridge on the cable-stayed bridge construction process the safety of the structure,main line is reasonable.Therefore,the design of cable force is the key problem in the design and construction of cable-stayed bridges.In this paper,based on the health monitoring system of the Liaohe River Bridge,the cable force of cable-stayed bridge is studied,the research contents include: a health monitoring system and the existing problems;optimization of cable force of cable-stayed bridge with steel box girder;effect of temperature field on the cable force of cable-stayed bridge;cable fatigue damage analysis and research.The main contents are as follows:Firstly,this paper introduces the constitution of the health monitoring system of Liaohe bridge,and lists several practical methods to determine the reasonable cable force,which provides the engineering background for the data analysis and Midas/Civil data simulation.Second,an integrated method is proposed for the optimization of cable forces.The method is used to integrate the existing optimization methods of cable forces,and to optimize the cable forces by using the advantages of each method.This method can be used to optimize the cable force of cable-stayed bridge by multi-step and multi-objective optimization.Third,using the comprehensive method mentioned in this paper to optimize the cable force of the bridge.After using the optimized method of cable force distribution,local cable force and uneven main tower near great change has been significantly improved,the dead load moment is reasonable,the force is reasonable,the overall force performance is significantly improved;the main tower of constant load displacement is greatly reduced,to a certain extent the main tower of offset control.Fourth,through monitoring the temperature field of the health monitoring system of cable-stayed bridge with steel box girder and the cable force,in-depth study of the temperature effect of Liaohe bridge steel box girder generated under the action of temperature effect on the cable force.The results show that the temperature changes and the cable force change has a positive relationship,curve fitting and outdoor temperature in the temperature field and the cable force at the same time,temperature meet the sine function,and cable force every day before 6h is linear,18 h satisfies Gauss distribution.By comparing the cable force difference between summer and winter,the greater the temperature change is,the greater the influence on cable force.Finally,the fatigue damage analysis of cable,data analysis shows that when the wind speed increases,the wind angle under the same condition,the cable damage also increases,on the other hand,when the wind speed decreases,the cable damage is reduced.It plays an important role in estimating the fatigue damage of the cable stayed bridge.