裂缝对钢筋混凝土桥面板的抗冲击性能影响研究

Study on Influence of Cracks on Impact Resistance of Reinforced Concrete Bridge Deck

钢筋混凝土桥面板在使用过程中,由于车辆等外荷载作用,混凝土结构表面会产生裂缝。为了研究裂缝对钢筋混凝土桥面板抗冲击性能的影响,采用数值模拟的方法,通过改变裂缝长度、宽度、深度,分析这些参数对含跨中裂缝的钢筋混凝土桥面板抗冲击性能的影响。抗冲击性能主要通过冲击力、跨中位移进行表征,结果表明:在其他相同条件下,含跨中裂缝的钢筋混凝土桥面板的抗冲击力随裂缝的长度、宽度、深度的增大而减小,呈负相关,而跨中位移则相反,与之呈正相关;裂缝尺寸的变化对板抗冲击力的影响大于对板跨中位移的影响,抗冲击力对裂缝深度最敏感;在受到冲击后,无裂缝板板底出现斜向“十”字形交叉裂缝,而带裂缝板板底出现正向“十”字形交叉裂缝。

During the service of reinforced concrete bridge deck,due to external loads such as vehicles,the surface of the concrete structure will produce cracks.In order to study the influence of cracks(length,width,depth)on the impact resistance of reinforced concrete bridge deck,this paper uses numerical simulation method to analyze the influence of these parameters on the impact resistance of reinforced concrete bridge deck with mid-span cracks.The impact resistance in this paper is mainly characterized by impact force and midspan displacement.The results show that under the same other conditions,the impact force of the reinforced concrete bridge deck with mid-span cracks decreases with the increase of the length,width and depth of the cracks,which is negatively correlated,while the mid-span displacement is opposite and positively correlated with it.The influence of the change of crack size on the impact force of the plate is greater than that on the midspan displacement of the plate,and the impact force is the most sensitive to the crack depth.After the impact,oblique‘cross’cracks appear at the bottom of the plate without cracks,while positive‘cross’cracks appear at the bottom of the plate with cracks.