Active Control Of Stress And Deflection Of Continuous Rigid Frame Bridge With High Pier And Large Span

Due to the need of economic construction,Asymmetric high pier long-span continuous rigid frame bridge (AHPLSCRFB) application became more and more widely, its security problem is more and more in need of attention, compared with the general continuous rigid frame bridge, high pier Long-span Continuous Rigid Frame Bridge in the closing period structure stress is more complex and alignment is not easy to control. To ensure correct bridge alignment, it is necessary to carry active control measure on the deflections and stresses of structure during the closure stage. In this dissertation, based on the Kaixia river bridge project, the active control technology of AHPLSCRFB during closure period is studied.Firstly, the effect of thermal load, concrete shrinkage and creep on the internal force and deformation of AHPLSCRFB during construction and operation stage. And through the comparison of side span, determined in accordance with the time sequence of the main span, span for optimal order.Secondly, the method for the determent of closurej force is studied. The closure jacking force is dependent on the temperature difference between the real temperature during structure closure stage and the design value. A reasonable pushing displacement and jacking force is obtained by finite element analysis. The effect of different closing sequence on the deformation,the internal force and the closure jacking force of the structure is also studied. And through the comparison of side span, the main span, span for optimal order is very reasonable.Finally, the closure section of prestressed steel beam different tension sequence of structure influence were researched, obtained the reasonable tension sequence. Finally, it puts forward the proposal on how to reduce the loss of prestress. It is suggested that the alternate beam is set up in time when the lower torsion is very big.