10th Asian Regional Conference of IAEG (2015)

Keynote speaker Topic 3
Mr. Yogendra Deva
ProfileHead-Geology, Indo Canadian Consultancy Services
LTD.,Noida, Delhi-NCR, India
E-mail: yogendradeva@gmail.com
Date of Birth: 20 July, 1951
Nationality: IndianTitles
2011-present: IAEG Vice President for Asia
2005-2012: Secretary of IAEG India National Group
2003-2004: Editor of IAEG India National Group (IndianSociety of Engineering Geology)
1994-1998: Joint Secretary of IAEG India National Group
Position Held2009-2015: Indo Canadian Consultancy Services Ltd. Noida( Head-Geology)
1977-2009: Geological Survey of India (Geologist, Sr. Geologist, Director)
Research Interests
Practicing Engineering Geologist.DPR and construction stage engineering geological investigations ofover 100 hydropower, irrigation and communication projects in India, Nepal, Bhutan, Myanmar,
Democratic Republic of Congo, Indonesia, Rwanda, Tanzania.
Over forty technical papers in India/ International Conferences. As Editor of IAEG India NationalGroup, edited Seminar Volumes, Journal of Engineering Geology of IAEG Indian National Group,
Constitutional amendments, etc.
Education
1974: M.Sc. Applied Geology, University of Delhi
1974-1977: Research Scholar/ Lecturer, Geology Department, University of Delhi
Abstract

Natural damming in the India Himalaya and its Impact on Hydropower Development
Occurring as a prominent convex arc of mountain chain in north India, the 2400 km long Cenozoic
mobile belt of the Himalaya is the product of collision between the Indian and Asian plates.
The Main Himalayan Belt is host to major hydropower development in India that, at present, is focusedin the Lesser Himalaya bound between the Main Central Thrust and Main Boundary Thrust, and is steppingout in to the Higher Himalaya north of the Main Central Thrust. The investigation and implementation ofthe hydropower projects in this belt are governed by complex geotechnical implications arising out ofunique site specific lithological and tectonic models. Not very infrequently, many of the project sites havecome across natural dams with silted up lakes posing serious foundation and 6unneling problems.
Generally, the low bearing capacity and saturated nature of the lacustrine deposits lead to seriously
adverse foundation conditions including liquefaction potential, and extremely difficult or eveninsurmountable problems in the construction and maintenance of subsurface structures like tunnels. It is,therefore, advisable to stay away from exceptionally thick alluvial deposits in wide valleys and, if that isunavoidable, to study and explore such a site thoroughly. This is not always possible and, if unavoidable,
adversely influences the techno-economic parameters of the project.
In particular, some of the major hydroelectric projects in Indian Himalaya that faced the geotechnicalinvestigation and construction challenge include the 390 MW Dul Hasti Project across the Chenab River in
Jammu & Kashmir, 780 MW Nyamjang Chhu Project across the Nyamjang Chhu River in Arunachal
Pradesh and 300 MW Baspa-II Project across the Baspa River in Himachal Pradesh.
The presentation takes a critical look at the phenomena of natural damming in the Himalaya and its
engineering geological and geotechnical implications with special reference to Dul Hasti, Nyamjang Chhuand Baspa-II Hydroelectric Projects.