Effectiveness of Post-injection Grouting in Controlling Leakage: A Case Study

Abstract

In many occasions severe water leakage problems are faced in shotcrete lined or unlined water tunnels that not only reduce stability of the rock mass but also result in loss of valuable water in conveying tunnel systems. Such leakage causes safety risks and increases the potential for huge economic loss to the hydropower projects. On the other hand, use of full concrete lining as final support increases the construction cost and time considerably. The best way to reduce leakage control and construction costs and time is the use of pre-injection grouting in the headrace tunnels. This paper discusses the role that post-injection grouting has played for controlling leakage through shotcrete lined/unlined low pressure headrace tunnel of the 60 MW Khimti I Hydropower Project in Nepal. DOI: http://dx.doi.org/10.3126/hn.v8i0.4903Hydro Nepal: Journal of Water, Energy and Environment Issue No. 8, 2011 JanuaryPage: 14-18Uploaded date: 16 June, 2011