Investigation and Evaluation of Increasing Uplift Pressure in an Arch Dam: A Case Study of the Huaguangtan Dam

摘要

The investigation of abnormal increases in uplift pressure can lead to the discovery of seepage paths that may cause damage to concrete arch dams. A new methodology has been developed in this study in order to analyze the causes of abnormally high uplift pressure increases and their influence on the structural safety assessments of dams. A series of borehole video tests were performed on an area of the Huaguangtan Dam and its foundations in order to investigate seepage phenomena under different working conditions. The reasons for the existence of the seepage paths causing abnormally high uplift pressures were identified by examining stresses on the dam, using a detailed three-dimensional numerical model. The results from the monitoring and on-site inspection showed that the high uplift pressure did not constitute a direct threat to the dam's safety. However, grouting treatment of the existing cracks was recommended so as to prevent them from developing further within the dam's foundations and to ensure the long-term stability of the foundation seepage. It was concluded that the methodology in this study could be used to solve practical engineering problems effectively as well as acting as a frame of reference for similar projects.