Design of grout curtain for temporary embankments on rock foundation

ABSTRACT

The design of curtain grouting for dams on rock foundations and the importance of finite element seepage analysis is reported by highlighting a case study of the upstream cofferdam of Gulpur Hydropower Project, Pakistan. Results from seepage analysis decreased the scope of curtain grouting by almost 3 times as compared to initial scope based on results from empirical correlations and water pressure tests. The total grouting holes were decreased from 185 to only 66 and this meant a decrease of construction time by 72% and saved a huge amount of capital and resources as well. The performance of the grout curtain is concluded to be satisfactory, for an operation phase of 3 years which includes two major floods as well and during this period, no visible erosion, quick condition or saturation was found on the downstream end. The paper concludes that if the safety criteria are satisfied, even with high inflows of the river, the scope of curtain grouting can be partially reduced or completely eliminated for temporary dams having an operational life of 1–5 years.

KEYWORDS:

• Grout curtain
• seepage analysis
• seepage control
• grouting design
• embankments foundation

Acknowledgments

The authors would like to thank Daelim Industrial and Lotte E&C for the permission to publish this paper. The authors also acknowledge the departments of QA-QC, Survey and Construction for their cooperation in providing information and data on time

Disclosure statement

No potential conflict of interest was reported by the author(s).