This article presents a unique method of installing a special type of embedded ultrasonic transducers inside a 36-m-long section of an old bridge in Germany. A small-scale load test was carried out by a 16 ton truck to study the temperature and load influence on the bridge, as well as the performance of the embedded transducers. Ultrasonic coda wave interferometry technique, which has high sensitivity in detecting subtle changes in a heterogeneous medium, was used for the data evaluation and interpretation. The separation of two main influence factors (load effect and temperature variation) is studied, and future applications of wave velocity variation rate $\mathrm{\Phi }$ for structural health condition estimation are discussed. As a preliminary research stage, the installation method and the performance of the ultrasonic transducer are recognized. Load- and temperature-induced weak wave velocity variations are successfully detected with a high resolution of 10⁻⁴%. The feasibility of the whole system for long-term structural health monitoring is considered, and further research is planned.

本文介绍了一种独特的方法，可以在德国一座旧桥的36米长的区域内安装一种特殊类型的嵌入式超声换能器。16吨卡车进行了小型负载测试，以研究温度和负载对桥梁的影响以及嵌入式换能器的性能。超声尾波干涉法技术具有很高的灵敏度，可检测异质介质中的细微变化，用于数据评估和解释。研究了两个主要影响因素（负载效应和温度变化）的分离，以及波速变化率的未来应用$\mathrm{\Phi }$讨论了用于结构健康状况评估的方法。作为初步的研究阶段，人们已经认识到超声换能器的安装方法和性能。负载和温度引起的弱波速度变化可以10 ^-4％的高分辨率成功检测到。考虑到整个系统用于长期结构健康监测的可行性，并计划进行进一步的研究。