Tracer Theory And Its Applied Research In The Analysis Of Dam Leakage

The theories and method about leakage detection of the river dyke, suchas geophysical, leakage measurement, CT's, integrated tracing technique, etc. are reviewed, but anyone of them can not determine the location, intensity, direction of leakage in the complex river dyke foundation. The integrated tracing technique is an effective method to detect deep leakage in a complex river dyke foundation and an important character is to integrate many methods so that the spatial developing mode of leakage passageway can be found clearly.Two case studies are used to explain the tracing method application in leakage detection of the river dyke. 77+000-77+270 reach of Daxiaoluhu Dyke is a dangerous reach for many years although it was be reinforced many times. By the integrated tracing detection, it is determined that piping at 77+250 section originates from leakage at silt layer, specially, from contact leakage at silt layer and upper clay layer, some concentration leakage passageways have formed and leakage flow mostly come from the section near piezometric tubes. By the integrated tracing detection, it has found heavy leakage at the back dam about 235.7m of Majiagou Reservoir. The integrated tracing detection has determined the location and origination of leakage. When water level is at 236.8m (below the design normal high level), some concentration leakage at the base rock, leakage at the dam base of both shores, three leakage points at the asphalt concrete core wall are found. They has harmed safe operation of the reservoir.