大型混凝土输水管涵浇筑质量GPR检测研究

Detecting on Pouring Defects of Large-scale Concrete Pipe and Box Culvert with GPR Method

南水北调东线山东段穿黄河及小清河工程分别采用大型输水混凝土管道和箱涵形式。结构物浇筑质量采用具有无损检测能力的探地雷达方法(GPR)和超声波法进行检测。根据探地雷达(GPR)检测结果,分析了浇筑混凝土结构物中混凝土骨料集中、密实度不均;隐伏裂缝等缺陷及钢筋网分布状态的GPR图像典型异常特征。并基于GPR检测电磁波速和超声波速的对比,讨论了低含水率条件下GPR方法对混凝土强度的检测能力。

large-scale concrete pipeline and box culvert were adopted to transport water crossing Yellow River and Xiaoqinghe River in South to North Water Diversion East Line Project.Ground Penetrating Radar（GPR） method and ultrasonic method were used to detect pouring defects in those concrete structures.By analysis of measured GPR sections,representative abnormal GPR images of different defects were given,which included uneven composition of concrete,porosity variation,hidden cracks and reinforcing steel bar mesh in concrete.Moreover,intensity of concrete also was been evaluated by contrasting velocity of GPR wave with that of ultrasonic wave while the water content of concrete is little.