Safety Evaluation and Rehabilitation for Buxi High CFRD with Face Slab Rupture

摘要

In recent years, face slab rupture has occurred on several high CFRDs, resulting in large leakage and even potential safety problems. In this paper, a case study on Buxi high CFRD (H=135.8 m) in China is conducted to illustrate mechanism analysis of the face slab rupture by using numerical analysis. It is found that large deformation and differential deformation of rockfill, cavity zones under the face slab, and structural defects of joints are the most important causes of the face slab rupture. Using the monitoring data, dam deformation and leakage were analyzed. This analysis predicts that leakage of the dam after rehabilitation will decrease by at least 80%. Rehabilitation measures are proposed and adopted for repairing the ruptured slabs and joints as well as the damaged waterstops. The leakage of the dam has decreased to less than 20% compared with the value for the same water level before rehabilitation, which is consistent with the pre-remediation prediction. Finally, conclusions are drawn, including suggestions for dealing with the face slab rupture issue of high CFRDs.