Earth/rock-fill dams and embankments are the main water retaining structures in hydraulic projects, and they can effectively resist floods and are of great significance for protecting people's lives and property. Leakage is a common problem in these structures. Investigation activities, including geotechnical, geoelectric, and tracing methods, are required to locate the leakage path and provide a basis for risk mitigation and reinforcement. These three methods provide information on different leakage characteristics, uncertainties, and spatiotemporal distributions. This work first introduces the micro-mechanism of internal erosion and then, provides a site case base for leakage investigation of earth/rock-fill dams and embankments from all over the world. For each investigation method, the basic principle, investigation process, data interpretation, and future potential are summarized. It should be emphasized that geotechnical, geoelectric, and tracing methods are placed on an equal level to assist dam managers and researchers in selecting the most appropriate method to assess dam leakage against specific geological backgrounds and structural types. Finally, the advantages, disadvantages, and applicable conditions of each investigation method are compared. The role of surface investigation methods and internal investigation methods in different stages of leakage is explained. The application of combined methods is discussed at four levels, and a new combined method is proposed.

土石坝、堤坝是水利工程的主要挡水建筑物，能有效抵御洪水，对保护人民生命财产安全具有重要意义。泄漏是这些结构中的常见问题。需要进行包括岩土、地电和追踪方法在内的调查活动来定位泄漏路径，并为风险缓解和加固提供基础。这三种方法提供了有关不同泄漏特性、不确定性和时空分布的信息。这项工作首先介绍了内部侵蚀的微观机制，然后为世界各地土石坝和路堤的渗漏调查提供了现场案例基础。对于每种调查方法，总结了基本原理、调查过程、数据解释和未来潜力。应该强调的是，岩土工程、地电和示踪方法处于同等水平，以帮助大坝管理者和研究人员根据特定的地质背景和结构类型选择最合适的方法来评估大坝渗漏。最后比较了各种调查方法的优缺点及适用条件。解释了表面调查方法和内部调查方法在泄漏不同阶段的作用。从四个层面讨论了组合方法的应用，并提出了一种新的组合方法。