Balance Works Of Plunge Pool Strengthening, KOLDAM HPS (4 X 200 MW)

Amount

DIVERSION DYKE WORKS

Design, and construction of Diversion dyke (approximately 330m Long with +-20% variation and crest level as EL 508 m) construction between Plunge pool and Satluj river by using River borne material as available at site (riverbed) and/or to use muck available within 1Km lead (if needed) including Loading, Unloading and carriage, including construction and maintenance of all temporary structures.

Design, Drilling and Performance of Jet grouting for seepage cut off works post spillway operation (including supply of materials like cement etc.) from top level of dyke as per standard codes and practices to make dyke impervious to keep working area at plunge pool in workable condition.

DEWATERING / SILT REMOVAL OF PLUNGE POOL

Design and execution of scheme for Dewatering and pumpable slush (Minimum 2,40,000 KL ) works (including all channelization and pumping works necessary to keep plunge pool empty and keeping it in workable condition) between the diversion dike and plunge pool.

Excavation/silt removal (by using dumper-excavator, dredger etc) from plunge pool and for making & maintaining of as needed for access track to reach at required level (at EL 482m and above, 400 to 450m long from dyke to EL 485m) for works related to secant piling, Rock anchoring, consolidation grouting, concreting.

Excavation in ordinary rock (basic dyke/ sheared phyllites/ carbonaceous phyllites etc) by mechanical means (excavator)/ manual means in plunge pool area including getting out and disposal of excavated material lead up to 500 m and for all lifts, as directed by Engineer-in-charge.

Formation of approach roads to left and right bank of the wrap around cladding wall by using River borne material as available at site (riverbed) and/or to use muck available within 1Km lead (if needed)

Systematic excavation along with slope protection of the left side corner of the plunge pool

Systematic excavation by mechanical means (Hydraulic excavator) / manual means in required area of plunge pool to achieve required gradient in slope, & using the excavated material for construction of dyke including loading, unloading & carriage including construction & maintenance of temporary structures. If excavated material is not required for dyke construction, then the material will be disposed at designated dumping location within 1 km lead.

Carriage of materials by Mechanical Transport including loading, unloading and stacking beyond 1 km up to 10 Km

Supplying & installation of double twisted Coated GI wiremsh size 60X 80 mm and 3 mm thick for slope protection inclusive of all manpower, material etc. as per technical specifications

Providing & fixing Fe500 grade 25mm dia cement grouted anchors by drilling up to 8 m and drilling hole in surface and grouting with cement grout all-inclusive as per the technical specifications.

SECANT PILING

Design and Installation of cast-in-situ Secant piles, vertical , unreinforced or reinforced having drilling diameter~ 900mm, with or without casing from approx. EL 482m-EL 489m , as per installation criteria (depth of pile may varying depending upon the site conditions), control of position and alignment, including all labour, material, equipment, handling transportation carriage and disposing off drilled/bored spoil etc., for all working conditions, preparation of scheme of boring/drilling casting/installing etc., and other services necessary to carry out the works of Secant piling as shown on the drawings or as directed by the Engineer-in-Charge, in a manner as specified.

Drilling of piles (including drilling vertically on inclined surface) of Dia 900mm (approx. 20m /30m deep ) in rock /silt/ pebbles/cobbles / conglomerate / boulder strata/concrete/ reinforced concrete by either using rotary method, percussion method or rotary cum percussion method with or without temporary casing.

Providing, placing and performing design mix cement concrete of strength 30Mpa (including installation of reinforcement cage in secondary piles) or as approved by Engineer-in-charge for secant piling with all labour, equipment, handling, batching, transporting, testing, mix design, mixing, conveying, placing by tremie method, carriage and disposal of unserviceable material of the pile, for all working conditions, preparation of scheme for concrete etc., all complete, as per specifications, drawings and instructions of the Engineer (necessary excavation and filling if any, is inclusive).Reinforcement shall be paid separately under respective item of reinforcement i.e .

CONCRETING

Providing and laying design/nominal mix, Cement Concrete as specified below, at all levels, for all kinds of works, such as mass concrete, lean concrete, drains, trenches, secant piles etc with all labour, material, equipment, handling, machine weighing batching, transporting, pumping, including removal of loose material/ scaling, mix design, mixing, conveying, placing and compacting, protecting and curing, testing for all working conditions etc all complete, as per specifications, drawings and instructions of the Engineer-In-Charge

1:1½:3 (1 cement: 1½ coarse sand (zone-III): 3 graded stone aggregate 20 mm nominal size).

1:2:4 (1 Cement: 2 coarse sand (zone-III): 4 graded stone aggregate 20 mm nominal size)

M30 RCC/PCC

Add for using extra cement in the items of design mix over and above the specified cement content therein.

REINFORCEMENT

Providing and placing reinforcement, as specified below, in reinforced concrete in required works, secant piles and other allied works, at all levels, for all kinds of works with all labour, materials, equipment, handling, transportation, cleaning, straightening, cutting, testing, including bending and placing, binding in position, concrete cover blocks/chairs and spacers, laps and anchorage, cover to reinforcement, preparation of bar bending schedules and getting it approved, all complete, as per specifications, drawings and instructions of Engineer-In-Charge

Thermo-Mechanically Treated bars of grade Fe-500D or more.

FORMWORK AND STAGING

Providing and fixing plywood/metal formwork with suitable overlay (film faced) for cast in situ reinforced or plain cement concrete to give and even and smooth surface to exposed faces of concrete at all levels

L shaped anchors

Horizontal/Inclined Drilling of holes for L shaped anchors of dia more than 66 mm and less than or equal to 125mm by percussion drilling/destructive drilling including washing of holes and redrilling (if required). (including Construction of Platform or similar work necessary for execution of rock anchoring work at specified location of Plunge pool) as per issued drawings through Reinforced Concrete/concrete/natural surface into the Rock/ underlying mass up to the required depth including cutting of reinforcement for Installation of rock anchors into the rock as per instruction of Engineer-in charge. The rate shall include all the cost of equipment, tools and Labour etc required for completion of job.

Supply and installation of cement Grouted type L shaped anchors 36mm Dia. up to 12 m long (including Construction of Platform or similar work necessary for execution of rock anchoring work at specified location of Plunge pool) and necessary grouting arrangements, placing of grouting pipes, admixture & grouting of required strength. Item includes supply of rock anchor required for execution as directed by Engineer- in-Charge. The rate shall include all the cost of grout and placing of grout, material, equipment, tools and Labour etc. required for completion of job.

INSTRUMENTATION

Drilling of hole of 150mm Dia. along with Supply and installation of MEMS digital inclinometer systems (including Bottom wheel assembly, In place Inclinometer sensor, Spacer tubing (length: as per the requirement), Placement tubing, Suspension kit, Protective cover, Junction box) as per specifications with digital data logger for each unit.

Drilling of hole 150mm Dia and depth 60m along with Supply and installation of Multipoint Borehole Extensometer as per specifications with digital data logger for each unit.

Supply and installation of Load cell (for 12m long 36mm Diameter rock anchors) of 30 T capacity with digital data logger for each unit.

Consolidation grouting of rock mass below and around cladding wall of plunge pool (including Construction of temporary Platform or similar work necessary for execution of grouting work at specified locations)

Drilling holes for grouting

Core drilling 50-125mm dia in RCC

Extra over AI for angle b/w 10-45

Destructive drilling 50-110mm dia

Extra over AIV for angle b/w 10-45

Providing & retriving casing pipe

Grouting & redrilling

Consolidation grouting of rock

Redrilling of grout holes

Material supply for grouting

Supply of OPC 43 grade cement

Supply of sodium silicate gel

Supply of sand

Supply of non-shrink compound

Testing

Conducting WPT in drill holes

DRAINAGE HOLES

Horizontal/Inclined Drilling of drainage holes of Dia more than 100mm and less than or equal to 125mm by percussion drilling/destructive drilling including washing of holes and redrilling (if required). (including Construction of Platform or similar work necessary for execution of work at specified location of spillway) as per issued drawings through Reinforced Concrete into the Rock/ underlying mass up to the required depth (approx. 10m) including cutting of reinforcement as per instruction of Engineer-in charge. The rate shall include all the cost of equipment, tools and Labour etc.

Supply and installation of Perforated PVC pipe 100mm dia (wrapped with a suitable free draining geo-textile) in drainage holes 10m long (including Construction of Platform or similar work necessary for execution of work at specified location of spillway). The rate shall include all the cost of material, equipment, tools and Labour etc. required for completion of item.

MISCELLANEOUS WORKS

Supplying and installing rock or boulder (including transportation/carriage) filled Gabions/wire crates in place as per approved drawings or as directed by Engineer-in-Charge. (Boulders shall be provided by NTPC on as is where is basis.)

Laying of half-filled cement Bags with soil/ local available material

Dismantling, chipping and making an opening in RCC and PCC by Core Cutting of dia not less than 120mm, depth up to 2 m

Core boring holes (using triple tube barrel) in concrete and all types of rock with diameter equal to at least 80mm and less than or equal to 120mm (Mainly NX and HX in IS 10208)