钢桥面浇注式沥青铺装复合梁疲劳损伤规律分析

Composite Beam Fatigue Damage Law of Steel Bridge Deck Gussasphalt Pavement

浇注式沥青混合料作为钢桥面典型铺装材料之一,与正交异性钢桥面板构成的组合结构,共同承载车辆荷载。为了探讨钢桥服役期间浇注式沥青混合料材料参数对其复合结构疲劳损伤规律的影响,采用三点加载的复合梁疲劳试验,采集试验过程中荷载、变形参数,计算复合梁损伤变量,分析材料模量、铺装厚度、荷载水平对复合梁疲劳损伤的影响程度。结果表明:相同变形条件下,较高模量的材料提高了铺装层刚度,但自身衰变速度相反更快;厚度变化与复合梁疲劳损伤速率基本呈线性关系;荷载变化对其影响非常大,特别是当施加的荷载初始挠度由0.6 mm增加到0.8 mm时,复合梁疲劳损伤速率加快了180%。

The gussasphalt mixture is one of the typical paving materials for steel bridge decks.The combined structure of gussasphalt mixture and orthotropic steel bridge deck bears the load of automobile.In order to investigate the influence of material parameters of gussasphalt mixture on the fatigue damage law of composite structure during service of steel bridge,the fatigue test of composite beam with three-point loading was adopted.Load and deformation parameters were collected during the test,and damage variables of composite beams were calculated.The influence degree of material modulus,pavement thickness and load level on fatigue damage of composite beam was analyzed.The results show that under the same deformation conditions,the material with higher modulus improves the pavement stiffness,but its decay speed is faster;the thickness change has a basically linear relationship with the fatigue damage rate of the composite beam,and the load change has a great influence on it.Especially when the initial deflection of the applied load increases from 0.6 mm to 0.8 mm,the fatigue damage rate of the composite beam increases by 180%.