关键词: 示踪试验, 多重裂隙网络分级, 渗透参数, 渗漏通道, 水文地质

Abstract: The problem of seepage in the fractured rock mass has become an important issue that threatens reservoir dam and underground powerhouse. Due to the existence of cracks with different scales in the fractured rock mass, the study of groundwater movement law in the fracture network can help to solve the seepage prevention in underground engineering. Taking a pumped-storage power station as an example, field tracer test was carried out between the upper reservoir and the underground powerhouse. According to the tests data, the fracture network was classified into multiple levels and the corresponding permeability parameters were calculated. The results showed that permeability parameter of each level basically decreases with the increase of fracture network series, and the leakage amount of each classification network is proportional to the water conductivity. At the same time, the results of laboratory experiments also verified the correctness of the law. Therefore, the classification of multi-layered fracture network can help to determine the size of the leakage channel of the fractured rock mass and provide a reliable permeability parameter for calculating the seepage of the fractured rock mass and the basis for the seepage prevention of underground engineering.

Key words: tracer test；classification of multi-layered fracture network；permeability parameters；leakage passage, hydrogeology