Research On The Friction Loss And Its Influence To The Structural Behaviors Of PC Continuous Rigid Frame Bridge

With the rapid development of highways in our country, bridge construction has come in the upsurge period hitherto unknown, PC continuous rigid frame bridge was developed fleetly by the advantage of its good wholeness,strong anti earthquake and large torsional stiffness in recent years, and it is the first choice in long span and tall pier bridges. Prestressed design is an important part in upper structure design. At present, oversized mid-span deflection always appears in long span prestressed concrete continuous rigid frame bridges used, the reason of which is that the structure prestressed loss is estimated lower.This article take the Shaoyong highway Xiangjiang bridge in Hunan Province as the project background , conduct the research of the rule of the prestressed loss in the long steeple through the field test, calculates the upper structure of the bridge with the research result, and combine the scence test result of stress to confirm stress of control section under the different operating condition.First, gave two methods (indirect method and direct method) to identify the prestress pipe deviation coefficient'k'that cause the structure loss of prestress. Through analyze prestressed cable along the stress and stress concrete box girder cross-section data,we can obtains reasonable pipe deviation coefficient'k', and discovers the change rule of prestress loss.Second, the analysis software of long span design calculates and control analysis is used to calculate the deflection and the stress situation of control section under the different operating condition for prestressed concrete continual rigid frame bridge, the pipe fraction factor which separately used which the standard to have stipulated and the field test obtains to carry on the computation, and conducting a comparative analysis to the result.Finally, uses the obtained test result, carries on the confirmation analysis to stress strain of the box girder essential section.The conclusion may provide reliable datum for structure construction controlling and guarantee the quality of construction. At the same time, the conclusion has guide significance for designing and constructing long span prestressed concrete bridges.