考虑预应力损失的混凝土梁徐变计算方法

Creep Calculation Method of Concrete Bridge Considering the Loss of Prestressing Force

将按龄期调整的有效模量法与有限元法相结合,建立预应力混凝土梁桥徐变计算结构分析模型。模型考虑预应力束对结构整体刚度的贡献及预应力损失和徐变变形的相互影响,较准确的实现施工过程中、长期荷载作用下的徐变计算。根据此模型编制预应力混凝土梁桥徐变计算有限元程序,对小凌河特大桥32m预应力混凝土箱梁进行计算。程序计算结果与实桥试验结果吻合较好,能较好地反映桥梁上拱及徐变应变。

A structural analysis model combines the age adjusted effective modulus (AAEM) method with the finite element method to calculate creep deformation of prestressed concrete bridge is presented. Consideration of the contribution of the prestressing tendons to global stiffness and the influence between the prestressing force loss and the creep deformation allows the creep deformation to be traced more exactly during the construction process and the long-term external loads throughout its service life. According to the model, a computer program to calculate the time-dependent deformation of prestressed concrete bridge is developed. In addition, a full-scale testing and simulation analysis of 32 m prestressed concrete box-girder of Xiaolinghe extra-long bridge is completed. The comparison between the theoretical analysis and the test results shows that the algorithm and the program can finish the calculation of the structural curve and creep strain efficiently.