钢筋混凝土拱桥极限承载力的参数分析

Parametric Analysis of Ultimate Bearing Capacity of Reinforced Concrete Arch Bridges

采用空间有限元模型,研究了活荷载分布方式、拱圈混凝土的强度、拱圈面内的抗弯刚度、矢跨比和初始几何缺陷等参数对钢筋混凝土拱肋极限承载力的影响。研究结果表明:拱圈混凝土的强度、拱圈面内的抗弯刚度和矢跨比是决定大跨度钢筋混凝土拱桥极限承载力的3个关键设计参数;初始几何缺陷会降低结构的极限承载能力,但降低的程度很小,一般情况下可以忽略该参数的影响;矢跨比在一定范围内取值时,随着矢跨比的降低,钢筋混凝土拱桥的极限承载能力也随之减弱,且不同的矢跨比取值范围对极限承载力的影响程度不同。

Based on the space finite element model, this paper studies the effects of live load distribution, concrete strength, in-plane bending stiffness, rise-span ratio and initial geometric imperfection on the ultimate bearing ca-pacity of reinforced concrete arch bridges. The results show that concrete strength, in-plane bending stiffness and the rise-span ratio are critical parameters to determine the ultimate bearing capacity of long span reinforced con-crete arch bridges. It also maintains that the initial geometric imperfections would reduce the capacity of the struc-ture with rather small degree of the reduction which can be ignored generally and within a certain range, the ulti-mate bearing capacity of reinforced concrete arch bridge would be reduced when the rise-span ratio decreases. It finds out that the influence degree of different rise-span ratio range is different.