摩阻损失在预应力连续梁桥中的分析与研究

在预应力混凝土桥梁中,由于较大的预应力损失而直接影响了结构的受力和变形,使结构过早的失效或破坏,预应力筋与孔道壁之间的摩阻是影响其预应力损失的主要因素之一.以郑州市某三跨连续箱梁桥的摩阻试验为背景,以弯曲通长束为主要研究对象,运用最小二乘法原理和二元线性回归方法计算了孔道摩擦系数μ和管道偏差系数k,同时结合桥梁结构有限元分析程序Midas对实际桥梁在不同摩阻系数下进行挠度和应力计算分析,结果表明:对于弯曲通长束而言摩阻损失对跨中截面处的影响更为显著,同时对该桥预应力施工提出了优化措施,这可以为同类型桥梁预应力张拉施工与计算控制提供参考.

Analysis and Research of the Friction Loss on the Prestressed Continuous Beam

In the prestressed concrete bridges , the stress and deformation of the structures are influenced by great prestressed loss so much that the structures are destroyed at early stages .Friction between the tendon and the duct is one of the main factors to the prestress loss .Based on the friction test of a three-span continuous box girder bridge in Zhengzhou City with the long beam as the main objective of study , the principle of least square method and the two element linear regression method are used to calculate duct friction coefficient μand pipe de-viation coefficient k.The actual bridge deflection and stress at different friction coefficient are calculated and ana -lyzed with the finite element structural analysis program Midas .The results show that the effect on friction loss for curved long beam especially at mid span section is more significant .Meanwhile , the optimized measures are pro-posed to the construction of prestressed bridge , which can provide reference for prestressed stretching construc-tion and calculation control of the same type bridge .