Comprehensive investigation of leakage problems for concrete gravity dams with penetrating cracks based on detection and monitoring data: A case study

The leakage amount is an important indicator evaluating the seepage behavior of a dam. Due to the complex behavior, crack development judgment and leakage behavior identification for concrete gravity dams remain a challenging task. The paper is concerned with comprehensive investigation of leakage problems for concrete gravity dams with penetrating cracks. A case study on Shimantan Reservoir Dam was taken to examine the utilization of the comprehensive investigation method. Deficiency investigations were undertaken to identify the nature and sources of defects responsible for the serious leakage. Based on the information acquired from field visual inspections and ground-penetrating radar tests, it is apparent that several transverse cracks penetrate the dam crest and propagate downward into the dam body. The results of the remedial grouting, X-ray diffraction analyses and water injection tests reflect the appearance of penetrating leakage paths in the dam body. Subsequently, 2 behavior models including the special hydrostatic-seasonal-time model and the inverse analysis model were conducted to distinguish the contribution of penetrating cracks to leakage amount. The special hydrostatic-seasonal-time model was modified to address the influence of leakage flow in real microcracks in concrete dams based on the Navier-Stokes equation. The result shows that the proposed models provide an acceptable accuracy in analyzing leakage monitoring data for gravity dams with penetrating cracks. Leakage flow in penetrating cracks plays a dominant role in the dam seepage field. The execution flow in this paper could be readily employed in investigations of similar problems of concrete dams.