桥面板混凝土理论厚度对组合梁桥收缩徐变的影响分析

Analysis on Influence of Theoretical Thickness of Deck Plate Concrete on Shrinkage Creep of Combined Beam Bridge

以《公预规》为依据,讨论了组合梁桥中桥面板不同理论厚度计算方法得到的收缩应变和徐变系数间的差别,提出了采用随时间变化理论厚度计算收缩徐变参数的方法。接着,以一座2×75 m连续组合梁桥为背景工程,建立有限元模型,针对不同桥面板混凝土理论厚度计算了结构收缩徐变引起的变形和应力。结论表明目前普遍应用的以施工铺装前截面计算桥面板混凝土理论厚度的方法得到的收缩徐变效应普遍偏大,但组合梁钢结构的部分计算结果偏于不安全。

Based on the Public Budget Rules, the article discusses the difference between the shrinkage strain and creep coefficients of deck plate in combined beam bridge given by the different theoretical thickness computation methods, and puts forward the use of the theoretical thickness computation shrinkage creep parameter method with the time change. According to the a 2×75 m continuous combined beam bridge and aiming at the different theoretical thicknesses of deck plate concrete, the finite element model is established to compute the deformation and stress caused by the structural shrinkage creep. The conclusion shows that the shrinkage creep effect now commonly applied is generally large by the method of sectional computing the theoretical thickness of deck plate concrete before the paving construction, and the partial computation result of steel combined beam structure is not safe.