基于模式匹配的网格扫描法在高铁线下结构检测中的应用

A gridded scaning detection method based on pattern matching for detection of high speed railway structures

高铁是连接地区交通的纽带,我国计划2030年将建成近4万km的高速铁路,形成八横八纵铁路网;但是高速铁路线下结构在长期的运营中会产生如混凝土裂缝、结构层脱空、砂浆层离隙等病害。高速铁路线下结构病害检测要求效率高、精度高、设备集成化程度高;针对高铁线下结构的典型病害CA砂浆层脱空及离隙,提出了基于模式匹配法的网格化扫描检测方法,该方法基于线下结构标准设计,考虑砂浆层离隙的空间分布特征,建立三维有限元模型;通过数值模拟,模拟不同病害下网格化扫描法接收的弹性波响应,完成病害特征匹配库;通过多轮匹配、权重值矩阵和阈值函数,设计了模式匹配算法,对匹配的结构损伤识别要素进行敏感性分析,通过合理设计网格尺寸实现病害平面分布20 cm内的精确评价。设计了网格化检波器阵列,成功应用到沪杭高铁虹桥站线下结构检测中,完成线下结构快速、实时、定量化的病害检测。

Major high speed railway structures are always facing the risk of damages,such as concrete cracks,reinforcement corrosion,structural aging and others in long-term operation.High efficiency,high precision,and integrated equipment are required in high speed railway detection.In this work,a grid scanning detection method based on pattern matching was proposed for detecting typical defects:CA mortar layer segregation of high speed railway under structure.A typical defect finite element model was established.The elastic wave response received by grid scanning under different defects was simulated to complete feature matching database through sensitivity analysis.The model matching algorithm was designed through multi wheel matching,weight value matrix,and threshold function.Through accurate design of mesh size,accurate evaluation of defect plane distribution within 20 cm was achieved.The grid detector array was designed and successfully applied to Hongqiao Hangzhou high-speed railway station under structure detection.A rapid,real-time,and quantitative damaged detection of the structure under the line was completed.