结合梁中混凝土收缩徐变引起的次内力分析

根据钢-混凝土结合梁的受力特点，考虑采用有支架施工方法，由力的平衡条件和变形协调条件，分析结合梁中由混凝土收缩徐变引起的内力重分布，以此为基础，进一步提出了连续结合梁内力重分布的计算方法。应用该方法分析了两跨连续结合梁算例，计算了混凝土收缩徐变引起的内力重分布。研究结果表明，混凝土收缩徐变对钢-混凝土结合梁有显著影响，足以使连续结合梁中支座负弯矩区的混凝土产生裂缝。

Analysis of the Secondary force in Steel-concrete Composite Girder Due to Shrinkage and Creep of Concrete

The shrinkage and creep secondary internal forces in steel -concrete composite girders are discussed by the analysis method. Taking into account the construction means of supporting frame, calculation formulas of evaluating secondary internal forces in simple beams are developed according to the deformation coordination of concrete plank and steel beam and equilibrium of internal forces in cross - section of the composite girder. A numerical method of secondary internal forces of constraint at supporting seats in continuous beam is given which based on the deformation coordination at intermediate supporting seats. It is shown that the influence of shrinkage and creep of concrete in steel -concrete composite girder is significant.