Research On The Effect Of Concrete Shrinkage And Creep For Continuous Rigid Frame Bridge In The Construction And Completion Stage

As the prestressed concrete continuous rigid frame bridge is the structure sensitive to concrete shrinkage and creep, they influence profile and internal forces significant, making the problem of prestress lose, deflection decline, stress redistribution and so on, all of which will lead to the bridge lose its function too early. So, correcting assessment the effects of shrinkage and creep on structure has an important theoretical significance in guiding the actual construction.This paper briefly reviews the characteristics and development process of the prestressed concrete continuous rigid frame bridge, the bridge construction control theory and technology. The mechanism of concrete shrinkage and creep is discussed. Firstly, taking the Qing Yi Jiang Bridge as an example, the finite element model of the bridge is built to check its calculation bearing capacity. Thereafter, the effect of concrete shrinkage and creep on the formwork erection elevation and nodes displasement of bridge is analyzed in terms of construction control. Also, the true results that caused by the load need to remove the results which generated by the temperature, concrete shrinkage and creep from the measured values. Lastly, this paper makes research on the effect of the concrete shrinkage and creeps on the internal force, profile and prestress loss of bridge. Besides, the effect of concrete shrinkage and creep on the shifting of pier-top for the continuous rigid frame bridge is analyzed. Because the concrete shrinkage and creep will lead to deflection decline in the bridge structure, some measurements are proposed to reduce long-term deflection of continuous rigid frame bridge by analyzing influence factors. This study provides a reference value for the construction control of similar bridge project.