@@ qrrqfilq rtq 3Tftqf,r dtr ffiq frrTr.r, t'5rrq1f .qrfq oTr@T yflofro T - frftelq -351 / w 7Xa HqtE"T/ tffiE- / 2012 / Geological Assessment of the alignment proposed for Chamund link motor road. District- Tehri Garhwal *{F4Tfrd- 31-frfl*il{-2012 "/ Geological Assessment of the alignment pronosed for Chamund link motor road, District- Tehri Garhwal, Uttarakhand. Viiav Dangwal 31-12-12 t. Introduction:- The Provinical Division, Public works Department New Tehri has proposed the construction of 0.50 km long Chamund link motor road in Tehri Tehsil. District- Tehri Garhwal. On the request of Er. Badan Singh, Executive Engineer, I carried out the geological Assessment of the proposed alignment on 30.12.12 in presence of Er. Y. P. Joshi, Astt. Engineer and Er. u. K Goel, p.D., p.w.D New Tehri. Z. LOCatiOn:- The Proposed alignment of Chamund motor link originates from km 4.0 of Tehri- Kirtinagar motor road and it ends at village Chamund, within 0.5 km length. The area lies in the close vicinity of New Tehri Town and Baurari Hamlet. :. GeOlOgiCal ASSeSSment:- Geologically the atignment of the proposed road is located in the middle lands of Garhwal Lesser Himalayan Belt, bounded by the Mail Central Thrust (MCT) in the north and Main Boundary Thrust (MBT) in the south. Another prominent ihrust namely Srinagar Thrust (ST) runs in between this beit which separates the rocks of Krol Nappe form the rocks of Garhwal Group. The proposed alignment is located the close vicinity of Srinagar Thrust and two different lithological units namely Chandpur phyllites and Nagthat Quartzites are exposed on its southern direction. The effect of Srinagar Thrust is clearely manifested on these rocks hence they are sheared and shattered in nature. Most of these rocks are thinly foliated, folded, partially weathered and dissected by five prominent joint sets. The entire alignment corridor of Chamund link road passes across the slope inclined at 200 to 350 in N 230 direction and the alignment slopes are covered with the thick cover of overburden material comprised of angular rock fragments embe<i<ieci in ciay- siit matrix. The slope forming overburden material is naturally well compacted and dense. Its "Undrained Shear Strength" at the site has been assessed ranging between 300 k Pa to 500 k Pa which coresponds to the consistency "Very Stiff'soils. The slope forming material do not contain any alkali content or dispersive / soft soil. Prima facie; the alignment slopes are stable and free from land slides/ mass wasting. 6ry& "| carried at the site On the basis of the geological / geotechnical studies are being made for the and the facts mentioned above the following recommendations construction of the ProPosed road' 4. Reccomendatign:- (i)Formtheroadbyfullexcavationofthehillslopes. walls all along the (iD Construct suitably designed retaining walls/ brest slope' road, it is essential for the overall stability of the hill cross (iii) construct large size lined long drain with the adequate drainage arrangements. (iv)Disposethedrainedwater.onthesafe/stableground. (v)Thedrainageworkmustbetakenupimmediatelyaftetthe excavation of the hill sloPes' down hill slopes' (vi) Do not dump/ dispose the excavated waste on the for long (vii) The excavated bench should not be rendered exposed it is period, the formation of the road must be taken up immediately, soastochecktheerosionoftheexcavatedsurface. (viii)Plantationworksontheeithersideslopeswillenhancetheoverall stability of the hill sloPe. carried out as per the standards (1x) A11 the construction activity must be the similar civil and norms following the BIS. codes prescribed for construction in HimalaYan Zone' 5.@onthebasisofthegeo1ogica1/geotechnicalstudiescarriedatthe was found geologically suitable for site and with the above recommendations, the site road in Tehri rehsil. District- the construction of 0.50 km long chamund link motor Tehri Garhwal, Uttarakhand' I ,'thrr'rl 4l ,.1 L4lt>lal. *iL gffira- (Vijay Dangwal) €Firt Gealogist -.a ) Sr. /-'rfri- Office of the Engineer in Chie .:# PWD Dehradun ili"." r'. ! ivq'lr.