桁腹混凝土梁桥的组合截面等效抗弯刚度

摘要

为使桁腹混凝土梁桥能够采用基于统一截面的单梁模型进行结构分析,文章提出组合截面等效抗弯刚度的概念与算法.引入共同工作系数K来反映截面的组合作用强弱,推导了等效抗弯惯性矩的计算公式.结合桥梁的常规几何参数,通过有限元数值分析得到了在不同腹杆倾角、桁架节间数条件下的桥梁跨中挠度,运用挠度校准和数值拟舍,得到了共同工作系数K的计算公式,最后通过算例验证了所提简化计算方法的适用性.%In order to employ the simple beam model to analyze the truss-web and concrete bridges, the concept and algorithm of equivalent flexural stiffness in composite section are presented. The consistency factor K was introduced to reflect the degree of composite action, and the formula for equivalent flexural moment of inertia was derived. Based on the essential possible configuration used in such bridges, the mid-span deflections were calculated by FEM for various geometrical parameters, such as the inclination angle of web member, the number of truss internodes. The expression for consistency factor K was thus derived via the method of deflection calibrated method and numerical fitting approach. The accuracy of the proposed method has been verified by numerical examples.