Performance of polyurethane grouting to handle heavy seepage in tunnels

DOI

10.2991/rare-16.2016.38How to use a DOI?

Keywords

polyurethane grout; head race tunnel; hydrogeology

Abstract

Fault zones, shear bands, underground water channels and other features in the Himalayan geology have made tunneling a very complex activity in the region. The major hydropower projects present construction problems but also render the project economically tough to handle. A case study is presented in this paper wherein heavy ingress of water in one of the tunnels is document. This problem has caused lot of disruptions and serious concern on feasibility of the project. One of the attempts of using polyurethane grout has been discussed and its implementation at the site is presented. Grouting is considered to be the most common defense towards water ingress in tunnel. Polyurethane grouting is a grouting technique that involves the injection of expanding polyurethane to cutoff water flow through joints or cracks or to fill voids beneath or behind subsurface of excavated area. The grout is injected with high pressure through a predrilled hole, grout then expands to fill the crack or void. Polyurethane grouts used for both leak sealing structures against high water flow and ground consolidation. The project in consideration is construction of head race tunnel (HRT) in TapovanVishnugad Hydro Electric Power Project (520 MW), Uttarakhand, India. The heavy ingress of water encountered with the high rate of seepage (1500 to 1800 l/min.) caused erosion and dissolution, resulting in collapse of the opening. Polyurethane grout was used to start remedial measure in order to stabilize the rockmass and to divert the excessive water seepage. In this paper discusses the challenges during remedial measures and stabilization, implementation approach and steps to handle heavy seepage using Polyurethane grout in the tunnel are described

Copyright

© 2016, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - N. Rana
AU  - R. Nair
PY  - 2016/11
DA  - 2016/11
TI  - Performance of polyurethane grouting to handle heavy seepage in tunnels
BT  - Proceedings of the conference on Recent Advances in Rock Engineering (RARE 2016)
PB  - Atlantis Press
SP  - 241
EP  - 248
SN  - 2352-5401
UR  - https://doi.org/10.2991/rare-16.2016.38
DO  - 10.2991/rare-16.2016.38
ID  - Rana2016/11
ER  -