Study On Liner Control Of Rigid Frame-Continuous Girder Bridges Construction

With the development of road building, rigid frame - continuous girder bridges become much more popular to meet the requirements of difficult terrain conditions. The regularity of stress and deformation changes of the structure is hard to achieve, because the Rigid Frame-continuous girder bridges are usually built with high piers, long girder by complicated method. And it is affected by a lot of parameters. Deformation control is a necessary program to make sure the bridge can be constructed correctly and safely.Based on the actual project this paper did a lot of researches on deformation control. This article introduced the development of Rigid Frame-Continuous Girder Bridge and current researches on deformation control, and presented the bridge control theory and method of structural analysis.According to finite element theory, this paper built the finite element model of the actual project using the finite element analysis software Midas/Civil and did a lot of calculation.Quantitative analysis results of many construction parameters under the largest cantilever state showed that Concrete density is the most sensitive parameter. The sensitivity of the elastic modulus ranked second. The relative humidity of the environment and two parameters of pre-stress loss are insensitive. Changes of temperature affect the deformation a lot. Certain measures should be taken to avoid the affection of temperature changes during construction. Construction order is important for the deformation of structure. It is avoided to change the order during construction. Data of deformation control must be recalculated if the order changed. Sensitivity analysis of many parameters are researched when the bridge is completed, it is known that loss of pre-stress force, concrete shrinkage and creep influence deflection of girder structure dramatically. These parameters must be controlled strictly. The construction process is very complex for long-span rigid frame- continuous bridge, and bridge status will be influenced by many parameters, So effective construction control is the assurance of quality and safety for the bridge. Determine control Strategy of the actual bridge was made According to simulation results and the actual construction process.This paper calculated the displacement of bearings, and made necessary adjustment.