Modification And Parameter Analysis Of Steel Truss Bridge Jacking Model Based On Measured Data

During the operation of the existing steel truss bridge,due to the damaged geological conditions,fatigue aging and corrosion of the bridge itself,the bearing capacity of the structure will decrease compared to its initial state with the passage of time,but it is common There are few studies on the construction analysis and related problems of the overall reinforcement and jacking of the steel truss girder bridge.The popularization and application of finite element theory and simulation analysis technology provides technical support for bridge reinforcement,and also puts forward higher requirements for reinforcement and jacking of dilapidated and old steel truss bridges.The normal operation of bridges is guaranteed,which promotes the progress of transportation in various places and drives social and economic growth.Based on the research background of an existing steel truss girder bridge,this paper corrects and verifies the finite element model by collecting measured data such as strain,deformation,temperature and modal on site.And based on the changes of stiffness parameters,temperature parameters,wind load,self-weight and other parameters,the linear sensitivity analysis of the bridge in the jacking construction stage is carried out.The main work of the paper is as follows:(1)Through reasonable and scientific means to collect data,the statistical analysis is carried out on the measured data of the stress,the lower chord elevation of the main girder,and the temperature of an existing large-span steel truss bridge at each measuring point.Through the statistical analysis of the measured data,the distribution law of temperature is revealed,which provides a reference for the following temperature effect analysis.(2)The finite element model is modified based on the response surface method,and the stiffness of each substructure is used as the correction parameter,and the modal of the steel truss bridge is used as the objective function,and the sensitivity factor and the sensitivity percentage are used to visually and quantitatively evaluate the influence of each factor;The Design-Exper data analysis software fits the structural response surface function and revises the initial model through the response surface equation.(3)On the basis of the revised model,the influence parameters such as stiffness reduction,temperature effect,wind load and temperature difference effect-wind load interaction,self-weight,etc.are introduced to complete a more accurate simulation of the actual reinforcement and jacking construction process.,and finally realize the deformation sensitivity analysis of the bridge structure.