Powerful parbati


Published on

Published in: Technology, Business
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Powerful parbati

  1. 1. POWERFUL ParbatiParbati Hydroelectric Power Project(6-8 WEEKS SUMMER TRAINING)A PROJECT REPORTSubmitted byJITENDER K. KASHYAPIn partial fulfillment for the award of the degreeOfBachelor of TechnologyINCIVIL ENGINEERING
  2. 2. Table of ContentsPRELIMINARIES Declaration CertificateAcknowledgement Abstract1. Introduction…………………………………………………………………..……3-52. Company Profile3.  Title of Project4.  Approach Road & Location of Project5.  Objective of Project2. Salient Features about Project……………………………...……………..…………6-133. Map location of parbati project……………………………..………..…..………..14-154. Testing of Different material performed at site……………………………..16-215. Common Machinery used in various parts of Project…………………………….22-336. Construction sequence………………………………………………………….....34-387. Main Components of Hydro Power Project……………………………………….38-53  Barrage, Wier  Desiltingarrangement.  Head race tunnel.  Surge shaft.  Power house.  Steel yard.  Tail race.8. Conclusion…………………………………………………………....54
  3. 3. DECLARATIONI hereby certify that the project entitled “HYDRO-ELECTRIC POWER PROJECT” by JITENDER K.KASHYAP, University Roll No. AACI01368B/09L in partial fulfillment of requirements for the awardof degree of B.Tech (Bachelor of Technology) submitted in the Department of Civil Engg. atunder ARNI UNIVERSITY ,KATHGRRH, INDORA (H.P) is an authentic record of my own carried outunder the Site Engineer Mr. MOHAMAD RAFIQUE . The matter presented has not been submittedby me in any other University / Institute for the award of B.Tech Degree.JITENDER K. KASHYAP (AACI01368B/09L)knowledge.Mr. MOHAMAD RAFIQUE Site Engineer(civil), Costal Project limited PARBATI H.E PROJECT STAGE-IIDam Complex, ManikaranMr. S.N. RANAUT (Project AM ,civil) Costal Project limited H.E PROJECT STAGE-II Dam Complex,Manikaran
  4. 4. ACKNOWLEDGEMENTMy grateful thanks go to Mr. MOHAMAD RAFIQUE– Site Engineer (Costal Project limited ). A bigcontribution from him during the Eight week was very great indeed . This project work makes merealized the value of working in construction project and a new experience in workingenvironment , which challenges me every minute . Not forget , great appreciation go to the rest ofProject Engineers , Supervisors and foreman , they help me from time to time and give knowledgeduring the project training . The whole Training time really brought me to appreciate the truevalue of learning and respect of seniors.Great deals appreciation go to the contribution of my training Instructor - Mr. RAJESH THAKUR(Costal Project limited). I am also would like to thankful to AM - Mr. S.N. RANAUT (Costal Projectlimited) , for the wise idea throughout the training time , and all the staff in the Costal Projectlimited PARBATI H.E PROJECT STAGE-II , Dam Complex, Manikaran office that patient in helping uscomplete this training project.Last but not least I would like to thank my friends or training mates especially those who learntogether at project site.
  5. 5. 1. Introduction1.1 Company profileCoastal projects limited (CPL) is one of theprosperous consruction companies in private sectorengaged in developing infrastructor projectsall over the country. The company icorporated in the year1995, is mainlyengaged in various civil works/construction activities in different states of the country.CPL has emerged as one of the pioneers and specialist in the underground excavation covering all jobs ofcivil construction of hydro power projects like power house complex, HRT, TRT, Surge Shaft , Surgechamber, Desilting Chamber, adits etc.
  6. 6. 1.2 Title of projectPreamble Himachal Pradesh is blessed with abundant water resources in its five major rivers i.e .Chenab,Ravi, Beas, Satluj and Yamuna, which emanate from the Western Himalayas and flow through the State.These snowfed rivers and their tributaries carry copious discharge throughout the year and flow withsteep bed-slopes, which can be exploited for power generation. As the power is the most important andmost essential input for economic development of any country. The standard of living in any country canbe judged by its power generation. The growth in agriculture and industry is entirely dependent on therate of growth in power sector. Of the 4501 MW identified hydel potential of the Beas Basin, thecontribution of the Parbati, one of its major tributaries, is the maximum. In Stage-II (Parbati-SainjLink),Parbati waters will be utilized at the Suind Power House in the Sainj valley. The Parbati Stage-III is arun-off the river scheme, envisaging the diversion of the tailrace release of Stage-II Power House as wellas inflows from Sainj river through a 7980 m headrace tunnel utilizing a design discharge of 177 cumecsat a maximum rated head of 326 m for generation of 520 MW (4130 MW) in a underground PowerHouse near village Bihali near the confluence of the Sainj and Beas Rivers . Power Demand in NorthernRegion The power demand has outstripped availability to an alarming extent in the country as a whole,and in the Northern Region in particular. Northern Region, already under severe power deficit, isexpected to be in the grip of acute power shortage even after accounting for benefits from the ongoingprojects. Central Electricity Authority (CEA) has estimated the hydroelectric potential in the country at84000 MW at 60% load factor. The installed capacity in the country has already grown to 107643.70MW by March 2003. Existing projects and projects presently under execution account for only about28552.56 MW, out of which 8696.57 MW is hydropower and 18660 MW & 1180 MW thermal andnuclear power respectively. It is anticipated that the Northern grid would be short of peak capacity ofabout 1156 MW by 2006-2007 and about 8161 MW by 2011- 2012. The need for Parbati HE Projectstage-III has therefore been considered in context of power shortage particularly peaking capacity inNorthern region.Hydel Development in Beas Basin Hydel potential of Beas basin has been identified as 4501 MW. Out ofthis Beas Sutlej Link Project (990 MW) Pong Dam (360 MW) Uhl stage I (110 MW) Uhl stage II (60MW), Malana (86 MW), Baner (12 MW) and Gaj (10.5 MW) are the projects already commissioned andin operation. Few projects viz. Larji and Uhl Stage III and Khauli are under construction. River Beasoriginates from Beas Kund a small spring near Rohtang Pass at elevation 4085 m. Unlike other majorrivers of Northern India, any natural lake does not feed this river. The river passes through famous KulluValley. Parbati River, Hurla nallah and Sainj River are major tributaries of Beas River in Kullu Valley. The
  7. 7. available drop of about 2640 m between Parbati and Sainj river was envisaged to be developed in acascade system (Parbati II and III) with an estimated installed capacity of about 1320 MW. (Layout mapshowing Parbati Stages II and III is presented in Fig. 1.2.).Parbati Stage II : developments are estimated to provide 800 MW hydro power.Parbati Stage II : involves construction of 90 m dam on Parbati River at Pulga. The water availability willbe enhanced by tapping streams Jagrai, Hurla and Jiwa. The powerhouse will be constructed near villageSuind. The construction work of Parbati Stage II is in progress.Parbati Stage III development utilizes tailrace releases of Parbati Stage II powerhouse as well as inflowsfrom Sainj River by constructing a diversion dam near Sainj village and underground Power House nearvillage Bihali utilizing a gross head of 356 m to generate 520 MW of power. The locations of ParbatiHydroelectric Projects Stage II and III are shown in Fig. 1.2Need for Further Expansion and Development of Parbati Hydroelectric Projects From the growth ofpeak demand, anticipated installed generating capacity and the schemes proposed underconstruction/consideration during 8th and 9th Five Year plan period it is observed that power supplyposition in the Northern Region would become more acute from the start of Tenth Five Year Plan andserious power shortage will have to be faced unless additional schemes are taken up immediately andimplemented to derive timely benefits. The most important source of power development in thenorthern region is its abandoned hydro resources located in Himachal Pradesh, Uttaranchal and Jammu& Kashmir. Among various identified schemes available for hydroelectric development, Parbatihydroelectric projects are considered very attractive from the point of view of deriving benefits at thestart of Tenth Plan.1.3 Approach Road & Location of ProjectStudy Area Location and Approach Kullu District is centrally located in Himachal Pradesh situatedbetween 31O20’25” to 32o25’0”N latitude and 76o56’30” to 77o52’20”E longitude covering angeographical area of 5503 sq.km. The District comprises three Tehsil viz. Kullu, Banjar and Nermand and2 sub-tehsils viz. Ani and Sainj. The project area is situated in Kullu district. The latitude and longitude ofthe Parbati Stage III dam site are 31o46‟N and 77o 15‟E respectively. It is a run-off river scheme,envisaging the diversion of tailrace waters of Parbati Hydroelectric Project Stage-II powerhouse togetherwith inflows from Sainj River. Parbati Hydroelectric Project Stage-III dam site is located at Suind and thepowerhouse at village Bihali about three km from Aut, a small town on the National Highway No. 21,about 28 km short of Kullu. The powerhouse and dam are located along the Aut-Sainj-Suind motorablestate PWD road. The powerhouse site of this project is connected to national highway (NH-21) at Aut onMandi-Manali highway through threekm motorable road. Project site is 208 Km from Shimla, 258 Kmfrom Chandigarh, 190 Km from Kiratpur and 508 Km from Delhi. The nearest rail head to the project siteis Kiratpur and the nearest airport is Kullu-Manali airport at Bhuntar. National Highway-21 is proposedto be widening as per IRC Class-A specifications of National Highway to carry the equipment andmaterial to project site. Project site is also connected to Pathankot (Punjab), which is a broad- gauge
  8. 8. Railway Station of Northern Railway and is about 250 km from Aut. Pathankot-Mandi road is a StateHighway at present, which will shortly have status of National Highway. In addition to the StateHighway, Pathankot is also linked through a narrow-gauge railway line up to Jogindernagar. (Locationmap of project site is presented in Fig.1.1.)
  9. 9. 2. Salient FeaturesSalient features of Parbati HE Project (Stage-II) is a run-off river development for power generation of520 MW. This project would generate 1977.23 million units in a 90% dependable year at 95% machineavailability. It will be operated as a peaking station. The power from this project would be fully absorbedin the grid. It is in this context that Parbati Stage-III hydroelectric project is being proposed forimmediate implementation. {Map showing study area (7 km radius from dam site) is presented in Fig.1.3}. Following are the broad components envisaged for the Parbati Stage II Hydroelectric Project:Location State Himachal Pradesh District Kullu River Sainj (a tributary of Beas river), which will alsoreceive water from tailrace of Parbati stage-II power house in Sainj valley. Location of Dam & PowerHouse Diversion dam on river Sainj at Suind village & Power House near Bihali village. Nearest Rail headKiratpur Nearest Airport BhuntarHydrology (Sainj River) Catchment area at diversion site 650 square km Snow catchment 152 square kmDiversion Tunnel Diameter 7.5 m, Horse shoe shape Length 445 m Diversion Discharge 800 m3/secInvert level at entry EL.1300.00 m Invert level at exit EL.1286.00 mDiversion Tunnel Gate Number & Size Sill elevation 2 nos., 3.0 m x 7.5 m EL. 1300.00 m Operatingplatform EL.1315.00 mCoffer Dams Location of U/S coffer dam 203 m u/s of dam axis Location of D/S coffer dam 185 m d/s ofdam axis Height U/S coffer dam 14 m (Top El. 1314.00 m) D/S coffer dam 6 m (Top EL. 1294.00 m)Diversion Dam Type Rockfill dam at Suind Dam Top EL. 1333 m Minimum river bed level at dam site EL.1292 m Maximum Dam height 43 m Length at top including spillway 229 m Length & Thickness ofDiaphragm Wall 90 m , 0.8 mSpillway Location Left Bank Type Orifice type Width of spillway 34.50 m No. of bays 3 Crest level ofspillway EL. 1298 m Width of each bay 7.5 m Thickness of piers 6 mRegulation Gates Hydraulically operated radial gates 7.5 mx12 m R.C.C Breast wall 23 m high Energydissipation system Ski-jump bucket with an apron and a preformed plunge pool. Design flood 3300m3/sec (PMF)Reservoir Full Reservoir Level (FRL) EL. 1330 m Minimum draw down level (MDDL) EL. 1314 mPre-Sedimentation Gross storage at FRL 166.79 ha-m Gross storage at MDDL 38.54 ha-m Live storage128.25 ha-m Reservoir area at FRL 12.51 ha Length of reservoir (fetch) 1.05 kmPost-Sedimentation Gross storage at FRL 98.92 ha-m Gross storage at MDDL 12.44 ha-m Live storage86.48 ha-m Reservoir area at FRL 8.78 ha Length of reservoir (fetch) 0.68 kmIntake Number & Size of Openings 2 nos., 9.5 m x 7.9 m Invert level EL. 1302.50 mBulk head gate (opening) 4.9 m x 5.5 m Service gate (opening) 4.9 m x 5.5 m Trash rack Inclined, at 100
  10. 10. Intake Tunnels Number 2 Nos. Size & type 5.5 m, D- shaped Design discharge from intake 106.20 m3/secin each tunnel Length of intake tunnels Size and length of construction adit to intake tunnel 390 m & 450m 6 m, D- shaped 500 mDesilting Arrangement Type Dufour type Number & Size of Desilting Chamber 2 nos, 16 m x 24 m x 350m Particle size to be removed 0.20 mm and above Gate operation chamber floor elevation EL. 1335 mSize and length of GOC of DC 6 m x 8 m, D-shaped, 73 m Size of gates 4.4 m x 5.0 m No. of gates & Sillelevation 2, EL. 1300.00 m Dimensions of access adit to GOC of DC 6 m, D- shaped, 160 m Dimensions ofbranch adit to DC 6 m, D- shaped, 200 mSilt Flushing Tunnel Nos., size, shape & length of branch SFT 2 nos., 2 m x 2.2 m, D-shaped, 200 m & 220m Main SFT size, shape & length 3 m, D-shaped, 180 m Gate operation chamber floor elevation EL. 1282m Size and length of GOC 6m x 8.5m, D-shaped, 35 m No. & Size of gates 2nos., 2.0 m x 2.0 m Sillelevation Dimensions- br. access adit GOC to SFT EL. 1273.75 m 6 m, D- shaped, 160 mHeadrace Tunnel Size, Shape & Length 7.25 m, Horse-shoe, 7980 m Design discharge 177 m3/secVelocity 4.06 m/sec Bed Slope 1 in 181 Size & shape of adits 6 m, D- shaped Adit No. Length HRT RDAdit-1- 190 m 60 m Adit-2- 720 m 4047 mAdit-3- 270 m 7892 mSurge Shaft Type Restricted Orifice type Diameter & Height 20 m Dia., 113.75 m Height Top elevation EL.1375 m Bottom elevation EL. 1261.25 mBulk Head Gate Nos. & Size 2 sets, 4.5 m x 4.5 m Sill elevation Surge Gallery EL. 1254 m 6 m, D-Shape,100 m long, 1:150 upwardBranch Adit to Surge Shaft Size, shape and length 6.5 m, D-shaped, 120 mPressure Shaft Main (2 Nos. starting from Surge Shaft) Type 2 Nos., Circular, steel lined Dia & Length4.50 m, 375 m & 345 m long each bifurcating into two Nos. 3.0 m penstocks near powerhouseAdit to Top of Pressure Shaft Size, shape of adit 6.5 m x 6.5 m & 7.5 m x 8.5 m, D-shaped. length of adit170 m & 40 mBranch Adit to Bottom of Pressure Shaft Size & Shape of adit 7.0 m x 6.5 m, D-shaped Invert level atPressure shaft junction EL. 959.25 m Length 240 mPower House Complex Type Underground Installed capacity 520 MW Size of Power House Cavern 122.9m x 23.2 m x 41.7 m Size of Transformer Cavern 98.2 m x 18.0 m x 25 m No. & Type of D/s SurgeChambers 4 Nos., Restricted Orifice Type Size of D/s Surge Chamber 15 m x 13 m x 44.0 m Type ofturbine Francis, vertical axis Generating units 4 nos. of 130 MW each Rated head 326.0 m Type ofswitchgear GIS type Size of pothead yard 100 m x 40 mElevation of pothead yard EL. 1075 m
  11. 11. Main Access Tunnel to Power House Size of adit 8 m x 7 m, D-shaped Invert level at Power House CavernEL. 974.00 m Invert level at Portal EL. 1065.00 m Length 1110 m Slope 1:12Approach Adit to Draft Tube “Gate Operation” Chamber cum Transformer Cavern Size of adit 6 m x 7 m,D-shaped Invert level at transformer cavern Length Nos. & size of Draft Tube Gate EL. 1000.00 m 130 m4 nos., 4.5 m x 4.5 m eachConstruction Adit to Powerhouse Crown Size of adit 6 m, D-shaped Invert level at Power house cavernEL. 986.00 m Length 250 mAdit to GIS Crown Size and Length 6 m, D-shaped, 350 m Invert Level EL .1017.0 mCable cum Ventilation Tunnel Size of Tunnel 6 m, D-shaped Invert level at Draft Tube gate cavern EL.1010.00 m Length 300 mTail Race Tunnel Size & Length 8.1 m diameter - Horse-shoe 2700 m long Outlet gate size 6.7 m x 8.4 mSill level at Outlet EL. 974.00 m Gate Operation Platform level EL. 984.00 m Minimum tail water level EL.974 mConstruction Adit for Tail Race Tunnel Size of adit 6 m, D-shaped Portal Elevation EL 1008 m Invert levelat Tailrace Tunnel EL. 956.7 m Length 460 mSlope 1: 9Power Generation Installed capacity 520 MW Annual energy generation in 90% dependable year at 95%machine availabilityEnvironmental Impact Assessment Objectives of the Study The proposed study covers: _ Assessment ofthe existing status of water, land, biological, climatic, socioeconomic,health and cultural component ofenvironment _ Identification of potential impacts on various environmental components due toactivitiesenvisaged during pre-construction, construction, and operational phases of the proposed HydroelectricProject _ Prediction of significant impacts on the major environmental components using appropriatemathematical/simulation models _ Preparation of environmental impact statement based on theidentification,prediction and evaluation of impacts _ Delineation of environmental management plan(EMP) outlining preventive and curative strategies for minimising adverse impacts during pre-construction,construction and operational phases of the proposed project alongwith the cost and time-schedule for implementation of EMP _ Formulation of environment quality monitoring programme forconstruction and operational phases to be pursued by the project proponentDetails of Work Plan under Each Environmental Component Water Environment _ Study of the regionalwater resources with respect to their quantity and quality _ Estimation of possible siltation in thereservoirs, and recommendations on appropriate watershed management practices (e.g. CatchmentArea Treatment) for enhancing operational life of impoundage _ Prediction of changes in water quality
  12. 12. due to impoundage _ Assessment of environmental impacts due to the projects at Dam sites, andupstream and downstream of Dam sites through impact networks Land Environment_ Delineation of landuse pattern in the catchment area through the analysis of remote sensing data _Identification of critically and severely eroded areas in the catchment _ Identification of the borrowareas and quarries for extraction of earth and stone materials for construction _ Identification andenumeration of land areas (Private, Government etc.) likely to be submerged _ Identification of criticalzones, viz. degraded forests, steep slopes, etc. through secondary information and remote sensing dataand ground truthing _ Prediction of loss of forest resources in submergence area_ Delineation of plans for restoration of excavation and stone quarry areas with recourse to integratedbiotechnological approach _ Delineation of compensatory afforestation and Catchment Area TreatmentMeasuresBiological Environment Aquatic _ Assessment of biotic resources with special reference to primaryproductivity, zooplankton, benthos, fishes and avifauna in impact area _ Identification of fish habitats,monitoring of resident and migratory fishes, assessment of fisheries potential in the reservoir, andrequirement of fish ladder _ Assessment of potential excessive growth of aquatic weeds andintermediate host vectors in the reservoirTerrestrial _ Collection of information on flora and fauna including rare and endangered species in thecatchment and submergence areas _ Identification of forest types and density in catchment andsubmergence areas, biodiversity and importance value index of the dominant vegetation in the impactregion of proposed project _ Collection of data on wildlife population (including birds), feeding areas,waterholes, migratory routes etc. in catchment and submerged areas _ Assessment of potential impactson national parks and sanctuaries _ Assessment of economic value of existing forests in impact area _Prediction of impacts on forests due to submergence, and assessment of changes in flora and fauna inthe submergence and command areas
  13. 13. 4.Climate and WeatherAssessment of changes in microclimate due to enhanced evaporation losses band atmospheric humidityPrediction of impacts arising out of increase in noise levels, particulate concentration, and fugitiveemissions during construction activitySocio-economic, Health and Cultural Environment _ Collection of baseline data on demography withspecial reference to occupational patterns, infrastructure resource base, and economy _ Collection ofbaseline data on morbidity pattern with specific reference to prominent endemic diseases _ Assessmentof information relating to tourism, monuments/sites of cultural, historical, religious, archaeological orrecreational importance including wildlife sanctuaries and national parks likely to be impacted by theproposed projects _ Collection of data on riparian rights of downstream users vis-à-vis proposed waterreleases _ Prediction of disruption in social life due to relocation of human settlements, submergence ofbridges and roads, and assessment of rehabilitation requirements _ Prediction of anticipated healthproblems due to vector borne diseases induced by water impoundage _ Prediction of health problemsrelated to changes in population density, and distribution of immigrant construction workers _Prediction of economic benefits to community and environment arising out of the proposed projects _Interaction with Non Government Organizations (NGOs), social organizations and communityconsultations in the areas likely to be impacted due to the proposed projects.Additional Studies Environmental Management Plan is delineated along with cost and time scheduleincorporating the following plans: _ Compensatory Afforestation Plan _ Green Belt Development Plan _Catchment Area Treatment Plan _ Ecological Conservation & Management Plan _ Reservoir RimTreatment Plan _ Free Fuel Supply Plan _ Landscape and Restoration Plan _ Muck Disposal Plan _ SolidWaste Management Plan _ Fisheries Development and Management Plan _ Resettlement andRehabilitation Plan _ Human Health Systems Management Plan _ Disaster Management Plan _Environmental Monitoring Programme.Fig. 1.1 : Location Map for Parbati Hydroelectric Project Stage II and IIIFig. 1.2 : Layout Map for Parbati Hydroelectric Project Stage I, II and III
  14. 14. 5. TESTING OF DIFFERENT MATERIAL PERFORMED AT SITEList of Practical Performed:Sr. No. Practical1. Cube Test & Detail2. Silt Content (For Sand)Cube Testing For Concrete CubesCube Mould :-15cm*15cm*15cmTamping Rod :-16mm dia. & 600mm lengthTest Detail: 3 cube- 7 days testing  3 cube- 28 days testingTesting Strength: 7 days testing strength- 70%  28 days testing strength- 100%Procedure:1. Cube will fill with three layers. 2. For each layer 35 tamping 3. Thickness of each layer should be equalto 5 cm. 4. Cube Strength = Load/Area 5. Cube Density = Weight/Volume 6. Standard Cube Weight = 8.1kgFig: Cube TestingSilt test for SandSilt can be determined by two methods:- By volume method  By weight method  By volume method% of silt = (Silt/Sand)*100According to CPWD specification actual result should not be more than 8%.Calculation of Material Used:For Example calculation of the material i.e steel & cement, fine aggregate, course aggregate for a smallsection of tail race:
  15. 15. PCC Calculation: Length 6.5m  Width 2.9m  Depth 0.15mVolume = 6.5 x 2.9 x 0.15 = 2.8275 m³ Grade used: M10 (1: 3: 6)Cement bag used = 1/10 x 1.54 x 28.5 x Vol= 12.409~13 bagsSand used (factor - 1.25) = 1.25 x 13 x 3= 48.75 cu ftAggregate used = 13 x 6= 78 cu ftSteel calculation:o Length 6.5m o Width 2.9m o Depth 0.15mo At side walls: 16 mm @ 130 mm c/c spacing and 8 mm @ 100 mm c/c spacingo At bottom Raft : 16 mm @ 130 mm c/c spacing and 8 mm @ 100 mm c/c spacingLength / Spacing = 6.5 / 0.130 = 50 x 2 bars = 100 bars = 100 x length of bars = 100 x2.9 m = 290 R/mtFormula to calculate steel bars:1 m = D2 / 162 = 162 / 162 x 290 = 458.27 kg/mConcrete used:Volume of figure shown above = 8.6285 + 8.6285 + 7.83= 25.087 m³Grade used : M 25 (1: 1: 2 )Cement bag used = ¼ x 1.54 x 28.5 x vol.= 275.27~275 bagsSand used = 275 x 1.25 x 1
  16. 16. = 343.75 cu ftAggregate used = 275 x 2=550 cuLay out plan for parbati Hydroproject:
  17. 17. 6. COMMON MACHINERY USED IN VARIOUS PARTS OF PROJECTEXCAVATOR:-Excavator is used for the purpose of excavate the hard strata. It has been used for variouspurposes in this project. Most of the excavation in Power house site , tunnel sites and road has beendone with the help of excavator. There are two types of excavators. JCB (It‟s a Scientist name : Joshafy Cyrail Bemford) Pocklane (Jcb with chain)HYDRA:Hydra is a machine which is use to carry heavy load like steel plates, heavy wires, cement concretemixer, steel bars and many more machineries. This get settled heavy machines to their site position.Fig: HydraLOADER:This machine is used to carry heavy material like stone, sand, aggregate and much more from one placeto another to reduces man power and time. This machine is mostly used inside the tunnel but smallloaders are use at site also to carry heavy material.Fig: LoaderBATCHING CUM MIXING PLANT:The company has installed their own batching com mixing plant on the site. Sand, 10mm and20mm are kept in separate heaps. These aggregate are drawn to the weight container with the help ofskipper. Plant has three gates for each size of aggregates.Cement comes from the ware house through conveyer belts. All these material are loaded tothe mixing drum according to weight specified from control room. Chemicals are added after cons.Discharges from the drum. Then whole conc. is loaded in to the transit miller and delivered to the site.
  18. 18. Fig: Mixing Plant or Beaching PlantFig: Mixing Plant with separate heaps of sand and aggregateJACK HAMMER:Jack hammer is generally used for drilling purposes. Its weight is normally 34Kg. It has ahandle on the top for the purpose of handling. It has two holds, one for compressed air and other forwater. Compressed air provides hydraulically force and force lubricant inside the jack hammer toprovide lubrication.Leg pusher (11Kg) is also attached to the jack hammer when we drill on the vertical face ofwall. Drilling rod is also attached to the front face of jack hammer. Rod had a bit on its front face, madeof diamond. Diameter of bit is 32.mm lengths of rod is 2.5f, 5.0Fig: Jack HammerCEMENTCONCRETE MIXER:Cement concrete mixer is used to obtain homogeneous mixture of cement, fine aggregate, courseaggregate and water which is not possible in case of manual mixing. Blades are fitted in the mixer andcertain rotation are given to get a homogeneous mixture of concrete.Fig: Cement concrete MixerVIBRATOR:In order to remove the voids which develop at the time of placing the concrete in any constructioncompaction is required to remove these voids and hence vibrator is inserted at the time of placing ofconcrete.Fig: VibratorROLLING PLANT:Rolling plant is use to roll the steel plates which are used for tunnel lining, penstock ferule, surge shaftlining and other rolling purpose.
  19. 19. TBM(Tunnel Boring Machine):The Parbati hydroelectric project is located in Himachal Pradesh (India). It is a cascade scheme, plannedto be developed in three stages with an aggregate generating capacity of 2070 MW. Stage-I of theParbati hydropower project that envisaged capacity of 750 MW was abandoned in 2001 due toenvironment-related concerns. Stage II of this scheme is a run-of-river scheme comprising an 85 m-high113 m-long concrete gravity dam near Village Pulga in Parbati valley. The reservoir will have a livestorage capacity of 3.09 million m3 , sufficient for four hours full load peaking every day even duringlean flow period. A discharge of 116 cumec from Parbati River and Tosh stream is diverted through a 6m diameter 31.5 km-long headrace tunnel on the left bank of Parbati to an underground „restrictedorifice‟ surge shaft 17 m in diameter that will feed two steel lined pressure shafts each of 3.5mdiameter having length of 1542 m and inclined at 30° to the horizontal. A gross head of 862 m so formedis utilized to generate 800 MW of power through 4 generating units of 200 MW each in the surfacepowerhouse is located on the right bank of the Sainj river near Suind village, 200 m downstream of theconfluence of the Jiwa Nala and Sainj rivers. Short tailrace channels will discharge the water from thepowerhouse to Sainj river. The project area lies in a high mountainous region in the remote part ofHimachal Pradesh and is prone to land slides and cloud bursts.Excavation in head race tunnel The 31.5 km long HRT of this project is the longest tunnel in anyhydropower project in the country and one of the longest in the world. The excavation of this tunnel isvery critical for the timely execution of this project. The HRT had been planned to be excavated throughsix adits. In absence of the possibility of an intermediate adit in the reach between adit 1 and adit 2, ithas been decided to excavate the HRT by the conventional DBM for a length of 22.476 km with finisheddiameter of 6.0 m and balance 9.05 km of circular shape by the open type hard Rock TBM. Theinaccessible terrain had restricted the amount of investigations in comparison to size of the project.Investigations revealed that the headrace tunnel will broadly pass through seven lithological units of twogeological formations, separated by a regional thrust known as Jutogh (Kullu) Thrust. The rockencountered was expected to be granite/gneissose granite, quartzite, biotitic schist with subordinateschistose quartzite. The incumbent cover had been ascertained to be 400 m to 1200 m. Anotherimportant feature of the area is the high angle reverse fault towards the end of HRT near surge shaft,the zone of which extending to 50-100m thickness. The TBM designed for HRT had been refurbishedRobbins TBM MK 27 of 6.8 m diameter. The cutter head is a closed, backloading type, with recessedcutters and equipped with low profile muckAdit portal of TBM(Tunnel boring machine)buckets and replaceable scrapers. The installed cutterhead capacity is 3150 kW and stroke length is2.050 m. The machine is equipped with 49 x 432 mm diameter cutters with recommended maximumoperating load per cutter as 267 kN. Nominal cutter spacing is 65 mm and maximum cutterhead rotationspeed is 5.77 rpm. Maximum machine thrust is 18550 kN and considered suitable for hard rock machine.Maximum total gripping force is 55600 kN carried over 4 gripper pads. The machine is equipped withring-mounted probe drilling equipment, which can cover 360 degrees of tunnel. The probe drills with themaximum probing length of 120 m are also intended for use in the installation of drain holes and forcover grouting. TBM has arrangement of rock bolting, wet & dry shotcreting and ring beam erector for
  20. 20. erection of heavy steel arches. The machine is also equipped with high performance injection groutingplant. In the event of unexpected geological conditions, drilling into rock ahead of face throughcutterhead would be possible in upper arc. After Launching the refurbished Jarva TBM in the end of May2004, the contractor Himachal Joint Venture (HJV) faced problems which commonly occur for an initialphase of a TBM drive such as repairs and replacements of electricalTwo types of TBM’s are used in PHEP-IIModel: Jarva MK27 (Hard rock TBM for HRT)Mitsubishi TBM MH1- NRM-BORETEC (Double shield TBM for pressure shaft)Boring diameter 6.8m 4.88m Boring stroke 2.05m(1:8 max used) 1.8m(0.5m only used) Machine length240m 126m Weight 760 tones 450 tones Cutter head design Flat type Flat type Cutters 17” 17” No. ofcutters 52 32 Cutter head speed 0-10 rpm(5.5 max used) 0-9 rpm Conveyor Belt conveyor Belt conveyorLength excavated 9.05 km 2*1546 m total = 18.142 kmRock supportSupport class Rock anchor Shotcrete Wire mesh RibClass-I 25Ø, 2m long (as req.)--- --- ---Class-II -do- 50mm thick in crown only--- ---Class-III 4 no., 25Ø, 2m long @1.5 m c/c longitudinally-do- 3.4mm Ø 100*100 mm2---Class-IV 6 no., 25Ø, 3m long @ 1.5m c/c longitudinally100mm thick in crown only-do- Steel rib is 150mm@ 8mm c/c 5 segment excluding adjustment pieceClass-v 6 no., 25Ø, 3m long @ 1.5m c/c longitudinally & 2 no. additional side wall anchors (if required)-do- -do- -do-
  21. 21. Achievement with double shield TBM at Pr. shaft- Excavation of left Pr. shaft=(11 months)19 Apr 2005-18 march 2006- Highest achievement rate of shaft no -1=233m in 1 month (Nov 05)- From bottom to top towards HRT - Right Pr. shaft=17 July 06-30 Nov 06 =5 months(record time)-Av. Highest achievement rate=299m/monthHighest=388m/month (Aug 06)HRT: - 31.5 km long. - Adit =6 no 1st=inlet Adit to HRT 2nd= Adit 3rd, 4th,5th ,6th =Adit2,3,4,5 - total face=F1,F2,F3,F4,F5,F6,F7,F8,F9,F10=9-out of 31.5 km long HRT about 25.5 km long has been completed. Longest stretch 5.8 km left to beexcavated betn. Face 38 face 4 .TBM from face 4 alone has to bore nearly 5km- after having excavated 4.056 km of HRT face –IV, boring is stalled since 26th Nov 06 after an incidenceof submergence of the machine in a sudden influx of water containing huge quantities Of silt and sand=>500 lt/minute ->1000 lt/minute 7000m3 sand and silt .(pressure =40 bars)Tunnel Boring MachineConstruction SequenceState-of-the-art equipment in operation for the construction of cut-off wall: ECC ConcordPre-grouting treatment To consolidate the ground to safely construct the cut off wall, Odex drilling andTube-a- manchete permeation grouting was done on both sides of the proposed cut off wall area.Pre-grouting worksBentonite Management Bentonite slurry was used for trench stability. Due to bouldery & highlypermeable ground, the management of bentonite was a crucial aspect. Preliminary tests were carriedout to define the best composition bentonite slurry. The bentonite slurry was prepared by mixing thebentonite powder to the water in a high speed mixer. After hydration, the bentonite mud was delivered
  22. 22. to the tanks for bentonite storage tanks. Bentonite slurry was circulated between trench and storagetank through mud pump, booster pump and desanding plant.De-Sander De-sanding equipment comprises of a series of vibrating screens to remove sand, gravel andhydro-cyclones to remove silt from trench slurryDesander for Bentonite management ECC ConcordTrenching Hydromill type trench cutter, 1.0 m deep, 2.8 m wide and 11.4 m tall mounted on Crawlercrane with inbuilt electronic system to monitor the performance of cutter during the time of itsoperation was used. While the cutting wheel‟s of the cutter, cuts & mides with bentonite shurry and apower mud pump bring the cutting to DG sanding plant.Trench cutter in operationChiselling A specially designed heavy chisel was used toadvance trenching through bouldersencountered during trenching.ChiselingTremie Concreting Concreting of the trenched panel was done by tremie method by which the concretewas poured under bentonite slurry without any mixing of concrete and bentonite slurry.Tremie concretingConstruction of Desilting Chambers: For the first time L&T isconstructing Desilting Chambers (an underground structure) at Parbati Hydroelectric Project in theHimalayan region. Rivers flowing from the Himalayan ranges normally carry lots of silt due to highvelocity of the river water. In power generation, if the silt is allowed to enter the turbine, the turbineblades are likely to get scoured resulting in costly maintenance. Desilting Chambers are thus constructedto prevent the formation of silt particles. In Parbati Hydroelectric Project, the Desilting Chambers aredesigned to remove sediments of particle size 0.3 mm and above. To flush the silt, Desilting Chambersare provided with 2 Silt Flushing Tunnels of size 2.0 m x 2.2 m which combine together to a 3 m x 3 msize D-shapedSilt Flushing tunnel back into Sainj River.Two Dufour type 250 m long DesiltingChambershaving a width 12.2 m and depth 22.5 m are constructed downstream of intake tunnels. A, D-shaped Adit of size 6.0 m x 6.5 m, has been built for facilitating the construction of Intake Tunnels andupstream portion of Desilting Chambers. The same Adit branches into another construction Adit leadingto the center of Desilting Chamber at its bottom to facilitate construction.Scope • Under ground excavation : 180000 cu.m • Rebar : 3200 t • Lining concrete : 41000 cu.m
  23. 23. Methodology Construction Sequence The construction sequence involved the following operations: Pilotdrift excavation & side slashing – The first pilot drift is excavated from construction Adit to DesiltingChamber by using conventional Drill Blast Method. Drifts of both Chambers are excavated in parallel.The sequences of activities carried out for the excavation included: Side slashing excavation was takenup after thecompletion of Pilot drift by conventional drilling & blasting method and rocks supported by rock bolts,wire mesh and 100mm shotcrete in two layers.Concrete Lining of the Chamber portion .A structuralsteel gantry of length 7.5 m was fabricated and erected for concrete lining of the Desilting Chamber. Ascissor platform was erected well in advance for carrying out the reinforcement work followed byconcreting. The concrete was conveyed by transit mixers and pumped in by concrete pump. Benchexcavation in stages - After the completion of chamber concreting works, contact grouting with lowpressure was carried out to fill the cavities around the concrete. The 12.0 m deep bench excavation wascarried out in four benches each of 3 m depth by using conventional drilling and blasting techniques.Then the rocks were supported by rock bolts, wire mesh and shotcrete. Lining concrete wall - L&TFormwork & Scaffolding was used for shuttering and platform. Necessary reinforcement was laid well inadvance and the concrete was conveyed by transit mixers and placed in position using a concrete pump.Excavation of hopper portion was carried out from the bottom Adit of the Desilting Chamber byconventional Drill Blast Method. Lining of hopper portion – After excavation was completed, concretelining work commenced from invert, wall and then this was taken to the slope portion. L&T formworkand scaffolding were used for the concreting.Achievements Enlargement of Desilting Chamber Crownachieved on 10th Aug‟07 against scheduled14th Sep‟07 i.e. 35 days ahead of schedule. Lining of Desilting Chamber Crown achieved on 23rd Feb‟08against scheduled 14th May‟08 i.e. 81 days ahead of schedule.concrete tunnel lining in desilting chamberHeadrace Tunnel Excavation methodology adopted as well as support measures provided in tunnelvaried from place to place depending upon site geological condition encountered at the work face.Tunnel Support After removal of excavated material from the face, the exposed rock is supported beforetaking up the next operation of blasting. Rock support is decided based on rock condition at the face. Toquantify rock at the face, rock mass classification system called “RMR” (rock mass rating) is being used.Support Methodology Shotcrete This involves applying a mixture of cement and water sprayed byshotcrete machine fitted with robot arm.Rock Anchor/Bolt Drilling of hole for the rock bolt is being carried out by Tamrock machine. Rock bolt isinserted in the hole and grouted either by cement grout or resin grout. A plate is placed outside on rockon the installed bolt and tightened by nut.
  24. 24. Wire mesh Wire mesh in rolls is brought to work face and fixing is done manually by using scissorsplatform. Wire mesh will be firmly fixed to the rock by fixing clips into the surface. Fixed wiremesh iscompletely covered by shotcrete layer of designed thickness.Steel RibStructural steel ISHB sections are fabricated and bent to the required shape, size and piece.Concrete Lining Concrete lining of HRT is taken up once the tunnel excavation is completed. Concretelining is the final support system in the tunnel and will be done in three stages using CIFA Gantry system.The three stages of concrete lining include Kerb Concrete, Overt Concrete and Invert Concrete. Concretewill be pumped through pipes installed on the Gantry. After concreting the required area, gantry will bemoved to the next position and concreting will continue as stated above. 6 cu.m capacity transitmixtures supply the concrete in to the tunnel.Special Tunnelling Techniques Where very poor rock conditions are prevailing or tunnel face is unable toadvance with conventional excavation methods, special tunnelling techniques are employed. For suchextremely poor conditions with adverse geology, following special tunnelling techniques viz.pregrouting, fore poling & pipe roofing are followed.Installation of pipe roofing Drilling and placement of 89mm diameter 21m long seamless pipes bySymmetrix drilling system around periphery of tunnel at spacing of 300mm. Drilling and installation ofpipes was done first in heading (above spring line of tunnel). To begin with grouting of primary holeswere taken up, followed by secondary holes. Primary holes are spaced at 600mm and secondary holes inbetween primary holes. Thus, pipe roofing and stabilization of tunnel with cavity formation was treated.Instrumentation To monitor the effect of installed support and monitoring of tunnel movement inunderground structures, specialized geotechnical instruments as follows are installed: TapeExtensometer - To measure convergence or divergence of tunnel Borehole Extensometer - To measurerockdeformation in the boreholes Load Cell- To measure load on the installed rock bolt/anchor Survey TargetPoint – To measure movement in rock and installed supportsCompleted portion of the tunnel:Branch tunnels to Head Race TunnelConstruction of Rock-fill Dam: Parbati Hydroelectric Project Stage II is situated on River Sainj. TheRockfill Dam is under construction at an elevation of 1302m above mean sea level, 3 km from village
  25. 25. Sainj in Kullu District of Himachal Pradesh. This is the second Rockfill Dam in India after Dhauliganga inUttranchal having a plastic concrete cut-off wall. Following are the salient features of the dam:Salient Features • Length of the Dam including spillway - 218 m • Base Width - 168m • Top Width - 10m• Height of the Dam - 43m • Quantity of Impervious core - 76000 cu.m • Quantity of rock fill - 2.64 Laccu.m • Quantity of transition & filter material - 1.03 lac cum • Reservoir capacity - 166.79 ha-m • Lengthof reservoir - 1.05 km • River bed Level - 1290 m • Full Reservoir Level - 1330 m • Length of Cut-off wall -117 mDiversion tunnel inlet Diversion tunnel outletConstruction of Diversion Tunnel Before commencing the construction work on the dam project, theflow of river had to be diverted from the main dam area. For this purpose, it was proposed to divert theriver through two diversion tunnels at the right bank of the dam. The tunnels were of 6.75 m finisheddiameter, horseshoe in shape having a length of 391m and 440m respectively. They were designed tocarry a discharge of 800 Cumecs (Cubic meter per second) of water. Each tunnel is provided with an inletstructure having three gates namely service, emergency and stop log gates for regulating the flow ofwater. A letter of appreciation was issued by Costal Project Limited for achieving the river diversion withadverse weather conditions and heavy rains.Construction of upstream and downstream cofferdam After diversion of the river, upstream anddownstream coffer dams were constructed. This was required to completely dry up the river bed so thatthe excavation work can be taken up. The upstream cofferdam prevented the water from spilling over tothe construction area and the downstream coffer dam prevented the backwater to seep through. Theheight of upstream coffer dam was 15m and downstream coffer dam was 5m. Curtain grouting wascarried out through the coffer dams to further increase the impermeability of the coffer dams. Thecoffer dam consisted of central impervious clay core followed by filter zone rock fill and riprap.Construction sequence of Rockfill Dam Construction of rock fill dam involved the following sequence ofoperations: • The entire area of the dam required clearing, stripping, and trimming to commence thefoundation work, followed by excavation for the trench along the line of the cut-off wall. • Constructionof the cut-off wall. • Consolidation and curtain grouting. • Embankment placing may be performedsimultaneously or as an independent activity on thecut-off wall • Placing the embankment fills up to the level of foundation of the parapet wall. •Construction of the parapet wall along the dam crest. • Placing of remaining fill materials on the damcrest, up to specified camber levels. • Installation of surface targets.Construction of rock-fill dam in progress