Study on Leakage Detection Method and Control Grouting Technology of Sleeve Valve Tube of Asphalt Concrete Core Wall Rockfill Dam

The significant disparity in the physical and mechanical properties of asphalt concrete core wall rockfill dam and foundation rock, coupled with the intricate stress state of the dam structure, the challenge of detecting and treating leakage, and the necessity for a comprehensive leakage detection method, prompted the formulation of this paper. The method, which is based on an engineering case, employs a two-step approach.First, it has analysed geological, design, and construction process data. Secondly, in order to ascertain the extent and nature of dam leakage, a comprehensive survey methodology have been employed, which is based on borehole detection methods, with the addition of several auxiliary geophysical exploration methods.The aforementioned leakage detection method has led to the development of two additional methods:the sleeve valve tube grouting method and the controlled grouting process with multiple slurry systems. These methods are designed to address the specific characteristics of the rockfill structure of rockfill dams. The results demonstrate that the proposed leakage detection method is capable of accurately determining the extent and nature of the leakage of the dam. The testing indexes after treatment with the sleeve valve tube grouting method and the controlled grouting process with multiple slurry systems meet the requirements. The core samples are well filled and cemented, and the total leakage of the dam has been reduced to 6.4 L/s from approximately 700 L/s, which is an evident consequence of the treatment.