NTPC LIMITED

PROJECT : Kudgi Super Thermal Power Project Stage-I, (3x800 MW)

PACKAGE NAME: ASH DYKE PACKAGE

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“Salient Technical Features of the equipment/systems/services covered in IFB No. 40039821 dated 03.06.2015, Bidding Document No. CS-9573-331(R1)-9 are mentioned below. These Salient Technical Features are mentioned only to facilitate the prospective bidders to prima-facie understand the requirements under the tender and shall not in any way limit or alter the scope of work and technical features/specification of equipment/ systems/ services covered in the Bidding Documents. Detailed provisions in regard of scope of work and technical features/ specification of equipment/ systems/ services, contained in the Bidding Documents shall be final and binding.”

SALIENT TECHNICAL FEATURES

Detailed Scope of work

The proposed ash dyke area is about 1.5 km from plant boundary towards MGR side. The scheme for ash disposal envisages two storage lagoons and one common over flow lagoon (OFL) for Bottom ash disposal and one storage lagoon & sedimentation basin for HC Slurry disposal. The topography of the proposed ash dyke area is highly undulating. Because of highly undulating ground, Bottom Ash (B A) Dyke top is provided at different levels for two lagoons. The total length of the starter dyke is estimated to be about 11.0 km. Construction of two well type water escape structure with flexible opening is also envisaged for decanting water from storage lagoon to over flow lagoon. Decanted water from One BA lagoon is directly connected by water escape structure to OFL. However, decantated water from 2nd BA lagoon shall be disposed into OFL through RCC channel along the periphery of Ash Dyke. Construction of spillways is also envisaged for discharging excess rain water from storage lagoons to OFL and from OFL to the existing drainage. Scope of work also involves construction of rock toe, toe drain and rip rap for down stream slope protection works of dyke embankment. Impervious lining to bed of one bottom ash lagoon and over flow lagoon with bentonite blended soil is also envisaged under scope of this package. Construction of bituminous inspection road and earthen trench all around the periphery of the dyke is also under the scope of this package.

All construction works shall be carried out based on the drawings which are released by the owner for construction.

The Work involved is mainly related, but not limited, to the following:

I. Preparation of work areas / clearing site / jungle clearance.

II. Ground stripping.

III. Excavation.

IV. Foundation preparation along with formation of steps and key pockets on sloping ground and steep gradient respectively.

V. Formation of the dyke section as per drawings including impervious clay core and filter.

VI. Formation of chimney, blanket and filter with 10mm & down aggregate and with coarse sand as per drawings.

VII. Construction of dyke rock toe, rip rap and filters for forming toe drain.

VIII. Dyke outer slope protection with turfing.

IX. Dyke inner slope protection with dry brick packing confined within brick masonry panel walls and with rip rap.

X. Construction of dyke slope drains/ stair steps.

XI. Construction of RCC works for water escape structures & Spillways.

XII. Laying and embedding RCC/MS pipes.

XIII. Earthen channel near toe drain for guiding excess rainwater - runoff.

XIV. Road works (WBM road over dyke Top and Bituminous Inspection road along periphery of dyke).

XV. Installation of instruments for monitoring purpose.

XVI. RCC Channel connection between Water escape structure & OFL.

SALIENT TECHNICAL FEATURES:

The scope of work includes the construction of starter ash dyke, covering two storage lagoons & one common over flow lagoon for bottom ash slurry disposal and one storage lagoon & sedimentation basin for fly ash disposal by HCSD system. Construction of two well type water escape structures & spillways is envisaged for decanting the water. Construction of RCC Channel from WES of the BA Lagoon to OFL is also envisaged for discharging decanted water.

The major work involved in this package is as given below;

1. Excavation in soil/rock = 1,40,000 cum

2. Earth work in Embankment Construction = 27,00,000 cum ( Borrow earth for Shell Zone)

3. Earth work in Embankment Construction = 6,25,000 cum ( Impervious clay core inside and outside):

4. Providing Sand/10mm & down aggregate filter = 2, 05,000 cum

5. Providing Aggregate filter = 20,000 cum

6. Providing Rock toe & rip rap = 25,000 cum

7. Concrete work = 8,300 cum

8. WBM = 22,600 cum

9. Bituminous Works = 2,800 cum