高速铁路线下结构典型病害分析及快速无损检测方法研究

摘要

随着我国高速铁路运营时间的增长和运营里程的加大,高铁线下结构出现了贯穿裂缝、层间离隙、脱空汲水等病害现象.其中CA砂浆层由于施工工艺、高速荷载及负压等影响出现了较普遍的层间离隙现象,局部还存在离缝及破损等病害,此类病害有可能引起列车振动的增大、噪音以及高速行驶时的安全隐患.针对高铁线下结构CA砂浆层病害的特点,基于弹性波在多层介质中的传播特性,结合现场可操作性以及检测速度的要求,提出了一种基于弹性波的检波器阵列式组合的快速检测方法.通过三维有限元数值模拟以及现场测试,对该方法的关键技术问题,包括评价标准、检测精度以及检测效率进行了研究.结果表明该方法可有效检测CA砂浆层层间离隙的空间分布,具有数据采集方便、检测速度快、检测精度高等优点.%Along with the fast growth of operation time and mileage of China's high-speed railways,many diseases and defects,such as,through cracks,segregations among layers,voids and so on appear in its underline structures.Due to effects of construction technology,high speed loading and negative pressure,segregations generally appear among CA mortar layers and there are serious cracks and damages locally.These diseases and defects may lead to overlarge vibration and safety problems of running carriages.Aiming at the defects' characteristics of CA mortar layers in undertrack structures,a rapid detection method was proposed based on a detector array group for elastic wave propagation in multilayer medium.Using the three-dimensional finite element simulation and field tests,this method's key technical problems including evaluation standard,detection accuracy and efficiency were studied.The results showed that this method can be used to detect effectively the spatial distribution of segregations among CA mortar layers with advantages of convenient data acquisition,faster detecting speed and a higher accuracy.