Durative Deflexibility Analysis And Actions Of Long-span PC Continuous Rigid Frame Bridge In Operating Period

With the advantage of smoothly driving，facilitate the construction structural rigidity，andgood overall performance， the PC continuous rigid frame bridge has been widely used inlong-span bridges. Because of that it has rapid development in our country in the eightieseven by now. But after putting into use，excessive deflection at the mid of span become anurgent problem.In prestressed concrete structures, it is important to know how much the prestress lossesis and estimate the creep exactly for the deflection of the structures. Therefore, the prestresslosses and the creep are the main reasons for continued the deflection of the main beam in theoperation period.This dissertation takes the examples of Yueliangbao Bridge.Tangxihe Bridge andYaojiapo Bridge and adopts the method of Finite Element Analysis method to analyse thesebridges. Mian research works of this dissertation are included below:①Make a review of development and researches about prestressed concrete continuousrigid frame bridges in China and abroad. From the structure, force design and construction,analyze the features of prestressed concrete continuous rigid frame bridge.②From the perspective of the prestress losses, analyzes the influence on deflection andthe corresponding conclusions.③Overview of the mechanism and various factors of the concrete shrinkage andcreep.We introduce the impact of long-term analysis of deflection on the concrete shrinkageand creep from Pre-camber Method and Zero Moment Method.We conclude that it is better tocontrol durative deflexibility by Zero Moment Method.④We can control durative deflexibility by increasing bottom slab tendons and top slabtendons in operating period. This thesis discusses impact on stress and displacement ofbridges when we increase different late tendons. Reasonable configuration of the beam canbe effectively control durative deflexibility of structures in late operating period.