Tunnelling Hazard in the diversion tunnel of sengulam augmentation scheme, Idukki District, Kerala

DOI

10.2991/rare-16.2016.50How to use a DOI?

Keywords

Sengulam Augmentation Scheme; diversion tunnel; causative factors; failure mechanisms; support intervention

Abstract

A free flow diversion tunnel is designed as a part of Sengulam Augmentation Scheme envisaged to increase the storage in an already existing reservoir at Sengulam, in turn power generation by transferring water available at Kallar River Basin. The tunnel is driven through gneissic bedrock with granite, alkali syenite and pegmatite intrusives. Completely weathered zones along selective intrusive bodies and four sets of shear zones are the geological adversities present in the rock mass that caused multitypes of failure during driving of the tunnel. The most susceptibile constituent mineral assemblages of fayalite bearing syenite and pegmatite in conjunction with syn/post intrusive shearing with influx of hydrothermal solution could be the reason for the abnormal depth of weathering. Caving, squeezing and flowing types of failure occurred in the tunnel reaches with thoroughly weathered rock. Whereas planar and wedge failures taken place in the sheared, fractured and closely jointed rock mass with mylonite or gouge filled smooth planar joints. The failure mechanisms, method of driving and support interventions are described in this paper

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  - K.R. Praveen
AU  - C.S. Vishnu
AU  - C. Thanavelu
PY  - 2016/11
DA  - 2016/11
TI  - Tunnelling Hazard in the diversion tunnel of sengulam augmentation scheme, Idukki District, Kerala
BT  - Proceedings of the conference on Recent Advances in Rock Engineering (RARE 2016)
PB  - Atlantis Press
SP  - 313
EP  - 317
SN  - 2352-5401
UR  - https://doi.org/10.2991/rare-16.2016.50
DO  - 10.2991/rare-16.2016.50
ID  - Praveen2016/11
ER  -