Rehabilitation of the Core Zone of an Earth-Fill Dam

This paper provides a detailed study of remediation work on the core zone of a damaged earth-fill dam. The relevant material includes a review of the dam surface survey data, leakage monitoring data, drilling method, grouting material, and drilling and grouting procedure. A compaction grouting method was selected as the remediation technique. In addition, the reduction and prevention of leakage and settlement were assessed. Compaction grouting was successful for filling voids, closing channels, and compacting the disturbed core soils. The loose or voided zones were properly filled, and the leakage was reduced after compaction grouting. Verification of the compaction grouting work was performed by evaluating the grouting pressures and volumes injected internally and by monitoring the dam leakage rate and tracer externally. All of these factors provide a good indication of changes inside the core of the dam, including reduction or closure of the leakage channels in the dam core.