预应力损失及合龙措施对大跨径PC连续刚构桥跨中下挠的影响

Study On Influence of Prestress Loss and Closure Measures on Midspan Deflection of Long-span PC Continuous Rigid Frame Bridge

以列夕特大桥为工程背景,采用有限元软件midas Civil分析了混凝土预应力损失、中跨和龙顶推和边跨平衡压重对其施工过程和后期成桥10年内桥梁跨中累积位移的影响。计算结果表明:预应力损失对跨中下挠的影响最为显著,其中底板束预应力损失影响最大,其次是顶板束,腹板束影响最小;中跨合龙顶推和边跨平衡压重的对桥梁跨中下挠的影响较小。对于1^(#)墩,当顶推力增加100 kN时,墩顶水平位移增加1.27 mm,对于2^(#)墩,当顶推力增加100 kN,墩顶水平位移增加2.16 mm。

Taking a bridge as an engineering background,midas Civil finite element software is used to analyze the effects of the loss of prestress,the balance weight of middle span,middle span and side span on the cumulative displacement of the middle span of the bridge during the construction process and 10 years after completion of the bridge.The results show that the prestress loss has the most significant effect on the Midspan deflection,and the bottom prestress loss has the most significant effect,the top prestress loss is the second,and the web prestress loss has the least effect The influence of middle span closing push and side span balance weight on the MIDSPAN deflection of bridge is small.For the No.1 pier,the horizontal displacement at the top of the pier increases by 1.27 mm when the pushing force increases by 100 kN,and for the No.2 pier,the horizontal displacement at the top of the pier increases by 2.16 mm when the pushing force increases by 100 kN.