石首长江公路大桥预应力混凝土箱梁张拉方案对比分析

Comparison and Study of Stretching Scheme for Prestressed Concrete Box Girder of Shishou Yangtze River Highway Bridge

针对石首长江公路大桥北边跨混凝土梁段,基于ABAQUS软件,采用桁架单元T3D2模拟预应力筋,实体单元C3D10模拟混凝土,建立了混凝土标准梁段的有限元计算模型。制定了预应力整体张拉和局部张拉两种方案,并对这两种方案下混凝土梁段的受力进行了对比研究。研究结果表明,混凝土箱梁的预应力张拉工序直接影响梁段在吊装和存梁阶段的整体受力。当采用局部张拉方案时,预应力混凝土梁段受力状况良好,满足设计要求。

For the north sidespan＇s concrete beams of Shishou Yangtze River Highway Bridge, the finite element calculation model of standard concrete beam is established based on ABAQUS software, in which truss element T3D2 is used to simulate the prestressed tendons, and the solid element C3D10 is used to simulate the concrete. The two schemes of prestress integral tension and partial tension are de- signed, and the stress of concrete beams under these two schemes are compared. The results show that the tensioning procedure of concrete box girder directly affects the integral stress of beam segment dur- ing hoisting and storage stage, and the stress condition of the prestressed concrete beam meets the de- sign requirements when the local tension scheme is adopted.