徐州某地铁线在建设中需经过一座拥有大埋深桩基的桥梁，为了判断其对地铁隧道施工产生的影响，需要对桥梁桩基的长度进行无损检测。在现场检测之前先于实验室内，根据现场实际情况采用冲击回波法对亚克力棒进行了长度检测的模拟试验，得到的结果与实际长度基本吻合，验证了冲击回波法应用于桥梁桩基埋深测量的可行性，同时总结出了传感器的布置点与信号质量之间的关系；后于工程现场，使用冲击回波法对待测桥梁桩基的埋深进行了测量并阐述了数据分析方法。结果表明：冲击回波技术应用于大埋深桩基的长度检测中是可行的，当工况复杂，传统的检测方法失去了工作条件时，可以采用该技术，其具有误差低、快捷高效以及工作环境适应能力强等优点。

The construction of Xuzhou metro line passes through a bridge with a large buried pile foundation. In order to distinguish its influence on subway tunnel construction, nondestructive detection of the length of bridge pile foundation is required. Prior to the on-site detection, laboratory studies of the simulation experiment were performed according to the actual situation of the acrylic rods by the shock echo method to detect the length, and it was found that the result and the actual length were consistent, which verified that the shock echo method was feasible for bridge pile foundation depth measurement. At the same time, the sensor layout and the relationship between the signal quality for engineering field detection were summarized. After that, the buried depth of bridge pile foundation is measured on site and how to analyze the data is expounded. The results verify the feasibility of shock echo technology applied to the detection of pile foundation length with large buried depth, and show that when the working condition of detection is complex and the traditional detection method loses the working condition, the impact echo method can be used for the detection, which has the advantages of low error, high efficiency and strong adaptability to the working environment.