The Mechanical Behavior Analysis And Monitoring Of Long-span Continuous Rigid-Frame Bridge With High Piers At The Construction Stage

Continuous rigid frame bridge with lightful line type,convenient and fast construction and long-span ability,it has been widely used in long-span bridges in the last 20 years.In order to make the state of the construction of long-span continuous rigid frame bridge is in good agreement with the ideal design(alignment and stress), it must be considered that the influence of mechanical behavior on the internal force and deformation during the construction of long-span continuous rigid frame bridge,and be able to correctly analyze the law of the key mechanical behavior influence the structure,is used to guide the engineering practice.The critical mechanical behavior that had a greater influence on the internal force and deformation of long-span continuous rigid frame bridge with high-rise piers are soil-pile interaction, nonlinearity and the final closure jacking force, etc.This article based on Rock Bay River Bridge as the engineering background and in view of the construction of long-span continuous rigid frame bridge. Through the Rock Bay River Bridge respectively set up considering soil-pile interaction and without considering simulation model, analysis the influence of soil-pile interaction on the internal force and deformation during the construction of long-span continuous rigid frame bridge.By comparing the influence of soil-pile interaction on long-span continuous rigid frame bridge of different high pier, the relationship between the pile-soil interaction and the height of pier. Through the Rock Bay River Bridge respectively set up considering geometric nonlinearity and without considering simulation model, analysis the influence of geometric nonlinearity on the internal force and deformation during the construction of long-span continuous rigid frame bridge.By comparing the influence of geometric nonlinearity on long-span continuous rigid frame bridge of different high pier, the relationship between the geometric nonlinearity and the height of pier.The primary purpose of Closure jacking force is to reduce the bad influence of pier stress and displacement what caused by upper structure concrete shrinkage,creep and temperature effect of continuous rigid frame bridge.It can be divided into the pushing force caused by shrinkage creep and the pushing force caused by closure temperature difference,the jacking force of the two parts can be calculated respectively.In this paper, based on the pier beam displacement of consolidation in the control to calculate the jacking force caused by creep and shrinkage. Respectively, based on main girder consolidation displacement, axial force, pier base bending moment for the target of jacking force under the action of the final closure temperature difference, and use the calculated closure jacking force to the model, for calculation and analysis for computing the final closure for the continuous rigid frame bridge in joining temperature difference effect of jacking force. On this basis, the large bridge jacking force of Rock Bay River Bridge is optimized, calculating the jacking force under different closure temperature conditions, to guide construction practice.In this paper, through the simulation calculation analysis on the Rock Bay River Bridge, the construction of the ideal state of the bridge linear, and used for construction control, ensure that the bridge internal force and deflection are within the allowable error range.This article also analyses the effect of soil-pile interaction, the geometric nonlinear effect on displacement and internal force of long span continuous rigid frame bridge, some useful conclusions are obtained and used to guide the engineering practice.Now, the Rock Bay River has been successful closure, actual state of bridge in good agreement with the theory bridge state.