不对称连续刚构的不对称系数

Asymmetric Coefficient of Asymmetric Continuous Rigid-frame Structure

为深入认识不对称连续刚构的不对称性所引起的结构力学特性,引入不对称连续刚构不对称系数的概念,确定该系数的合理范围以保证结构的合理性。将已建成贵州思南县岩头河大桥结构的大T构对称形成对称连续刚构,从该对称刚构中一个T构的主梁根部依次对称去掉悬浇节段,形成20个不同的不对称系数模型,(含对称结构)。对模型进行适当假定与简化,采用大型有限元软件Midas/Civil,计算得出跨径不对称下连续刚构在自重、活载、系统升温、基础沉降及各工况组合下的支点反力,并得出结构在各工况及各应力组合下的应力。分别对比分析了支点反力和应力在不对称系数变化下的变化规律,确定出不对称连续刚构的不对称系数合理取值范围为0.4≤η≤1.0,对不对称连续刚构在实际工程中的应用具有一定指导意义。

For in-depth understanding of mechanical properties of asymmetric continuous rigid-frame structure caused by the asymmetry, we introduced the concept of asymmetry coefficient, and determined the reasonable range of the coefficient to ensure the rationality of the structure. We expanded the existing symmetric T-frame of Sinan Yantou river bridge into the symmetric continuous rigid frame, symmetrically removed cantilever segments one by one from the main beam root of a T-frame of the symmetric rigid frame to form 20 models with different asymmetry coefficients （containing symmetrical structures ）. After appropriate assuming and simplifying the models, by using large-scale finite element software Midas/Civil, we calculated the support reactions of continuous rigid frame with asymmetric spans under dead weight, live load, system heating, foundation settlement and combination of all conditions, obtained the stresses under all conditions and combined stress, and comparatively analyzed the variation of the support reaction and the stress with different asymmetry coefficients respectively. The reasonable numerical value range of asymmetry coefficient has been determined as 0.4≤η≤1.0, which is of certain guiding significance in the actual project of asymmetric continuous rigid-frame structure.