P.C.连续刚构桥施工过程的仿真分析

现代P.C.(预应力混凝土)连续刚构桥受力复杂,成桥应力同施工过程相关。根据其结构及受力特点,提出用实体退化单元建立P.C.连续刚构桥施工过程分析的三维模型;将预应力筋作为结构的一部分,用等效节点荷载模拟预应力的张拉效应;用三参数粘弹性模型模拟混凝土徐变效应;提出了阶段模型应力的处理方法。以一实际刚构桥为对象对该方法进行了应用研究。结果表明:P.C.连续刚构桥在恒载状态下,成桥应力和挠度与施工过程密切相关,常用的一次成桥方式获得的成桥应力和挠度与实际有较大偏差。

SIMULATION FOR CONSTRUCTION PROCESS OF P.C. CONTINUOUS RIGID FRAME BRIDGE

For a modern P.C.(prestressed concrete) continuous rigid frame bridge,its stress state is complicated,and affected by construction process.To simulate its structural behavior during construction process,degenerate solid elements were used and a three-dimensional model was set up.Taking prestressed reinforcement as a part of structure,the equivalent nodal load was obtained to calculate the effect of tensioning bars.A three-parameter viscoelasticity model was adopted to simulate the concrete creep.A processin...