Parameter Sensitivity Analysis Of Multi-span Rigid Frame-continuous Composite Girder Bridge And Construction Monitoring

Multi-span Rigid frame-continuous composite girder bridge is widely used in the high-pier and large-span structure of uneven terrain and different pier height during the past few years.As rigid frame-continuous composite girder bridge is a complex statically indeterminate structure,it takes long construction period and requires high technique.Parameters,such as the structural design parameters,temperature load,concrete shrinkage and creep effect,closure sequence etc,that affecting the structural state are more in the construction process.The differences of parameters cause deviation between the actual finished state and the design ideal state,and affect the normal use in the daily operation stage.It is necessary to implement monitoring and master the state of the actual construction process.Then analyze and adjust parameters,in order to meet the design requirements of the finished bridge line and stress.This paper bases on Zhunxing Yellow River bridge project in the Inner Mongolia province.First,the sensitivity of design parameters in the rigid frame-continuous composite girder bridge are analyzed,including concrete density,elastic modulus and loss of pre-stress value.Introducing the concept of sensitivity coefficients identify the main design parameters during the largest cantilever state and the finished bridge.It can conclude that the down-warping of main girder is growing rapidly as a bridge for 5 years,the full-bridge integral down-warp but each span is slightly different for 10 years,through analyze the effect of concrete shrinkage and creep effect.Then analyze the structural stress and displacement state through the temperature load affect,and put forward the measure to control temperature load effect.In the end,analyze the actual displacement and stress state in the different closure sequence,and determine the reasonable closed project.On the basis of the above analysis,present the construction monitoring scheme of Zhunxing Yellow River bridge,including monitoring contents,methods,system,etc.Comparating analyze the structural linear and stress data between the measured and theoretical analysis results,the conclusion is given finally.