管拱面内两点非对称加载试验研究

Experimental study on tubular arches under unsymmetrical two concentrically in-plane loads

对钢管混凝土拱和钢管-钢管混凝土复合拱进行面内两点非对称加载试验。建立了双重非线性有限元计算模型,对模型拱的挠度、钢管应变、材料非线性与几何非线性影响、管内混凝土对极限承载力的影响进行了分析。分析结果表明,管内混凝土提高拱的极限承载力的能力与拱的加载工况有关,当拱以受弯为主时,这种提高作用较小,当拱以受压为主时,这种提高作用较大;在受力全过程中,材料非线性的影响是主要的,几何非线性的影响是次要的,但由于存在耦合作用,分析时应考虑双重非线性的影响;对于复合拱,拱肋在变刚度靠空钢管一侧的受力情况较为复杂与不利。

Experiments on CFST arch and hybrid arch of steel tube and CFST under unsymmetrical two concentrically in-plane loads were carried out. The deflections, strains of steel tube, effect of material non-linearity, geometrical non- linearity and the effect of filled concrete to the ultimate load-carrying capacity of tubular arch were analyzed. The analytical results showed that the promotion effect of the filled concrete on the ultimate load-carrying capacity of tubular arch is closely related to the loading cases. When the loads produce bending moments as the dominant forces in the arch, the promotion effect is rather small; however, when the loads produce axial compressive forces as the dominant ones, the promotion effect becomes large. In the whole process of the tubular arches, the effect of material non-linearity is more important than that of geometrical non-linearity. If both nonlinearities are present, they should be considered all together, since the effects are compounded. For a hybrid arch, the behavior of the hollow steel tubular rib near the end of the CFST arch rib is quite complex.