North Karnpura STPP, (3x660 MW)
ASH DYKE PACKAGE
SALIENT TECHNICAL FEATURES INCLUDING SCOPE OF WORK
“Salient Technical Features of the equipment/systems/services covered in IFB no 40046390 is 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:
The proposed ash dyke area is adjacent to the plant boundary. The scheme for ash disposal envisages two storage lagoon with sedimentation basin for disposal of fly ash and a smaller storage lagoons & an over flow lagoon for the disposal of separate bottom ash in the ash disposal areas. The topography of the proposed ash dyke areas is undulating. Ground level is varying from RL 432M to 458M for Ash. The total length of the starter for both the dykes is estimated to be about 8350M. Construction of well type water escape structure with flexible opening is also envisaged for decanting water from storage lagoons to over flow lagoon/sedimentation basin. Decanted water from storage lagoons through RCC well will be collected into over flow lagoon (OFL). Construction of spillways is also envisaged for discharging excess rain water from storage lagoons to OFL/RCC perimeter drain 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 bottom ash storage lagoon and OFL with bentonite blended soil is also envisaged under scope of this package. Construction of bituminous inspection road and RCC perimeter drain all around the periphery of the dykes is also under the scope of this package. Scope of this package also include preparation of earthen bed by excavation for nallah diversion.
All construction works shall be carried out based on the drawings which are released by the owner for construction.
The major work involved in this package will be as given below;
Earth work in Embankment Construction = 20,00,000 cum ( with earth excavated from inside ash pond area))
2. Providing Sand filter = 2,70,000 cum
Providing Aggregate filter = 16,000 cum
Providing Rock toe & rip rap = 16,000 cum
Reinforced concrete work = 11,000 cum
Water Bound Macadam = 20,100 cum
Clay bricks = 1,05,00,000 Nos.
Bituminous Courses = 7,700 cum
Non woven Geotextile = 10,000 Sqm
The scope and description of work covered under this package has been specified in relevant clause of Technical specifications. However, the Contractor may note the brief description of works of this package as below:
The proposed ash dyke area is adjacent to the plant boundary. The scheme for ash disposal envisages two storage lagoon with sedimentation basin for disposal of fly ash and a smaller storage lagoons & an over flow lagoon for the disposal of separate bottom ash in the ash disposal areas. The topography of the proposed ash dyke areas is undulating. Ground level is varying from RL 432M to 458M for Ash. The total length of the starter for both the dykes is estimated to be about 8350M. Construction of well type water escape structure with flexible opening is also envisaged for decanting water from storage lagoons to over flow lagoon/sedimentation basin. Decanted water from storage lagoons through RCC well will be collected into over flow lagoon (OFL). Construction of spillways is also envisaged for discharging excess rain water from storage lagoons to OFL/RCC perimeter drain 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 bottom ash storage lagoon and OFL with bentonite blended soil is also envisaged under scope of this package. Construction of bituminous inspection road and RCC perimeter drain all around the periphery of the dykes is also under the scope of this package. Scope of this package also include preparation of earthen bed by excavation for nallah diversion.
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:
Preparation of work areas / clearing site / jungle clearance.
Ground stripping.
Excavation.
Foundation preparation.
Formation of the dyke section as per drawings.
Formation of sand chimney, sand blanket and filter as per drawings.
Construction of dyke rock toe, rip rap (with geotextile) and filters for forming toe drain.
Dyke outer slope protection with turfing.
Dyke inner slope protection with dry brick packing confined within brick masonry panel walls and with rip rap.
Construction of dyke slope drains/ stair steps.
Construction of RCC works for water escape structures & Spillways.
Laying and embedding RCC/MS pipes.
Earthen channel near toe drain for guiding excess rainwater - runoff.
Bituminous Road works (over dyke top & Inspection road along periphery of dyke).
Installation of instruments for monitoring purpose.
Diversion and training of existing nallah.
The scope of works involves construction of two storage lagoon with sedimentation basin for disposal of fly ash and a smaller storage lagoons & an over flow lagoon for the disposal of separate bottom ash in the ash disposal areas. Construction of well type water escape structure with flexible opening is also envisaged for decanting water from storage lagoons to over flow lagoon/sedimentation basin. Construction of spillways is also envisaged for discharging excess rain water from storage lagoons to OFL/RCC perimeter drain and from OFL to the existing drainage
The detailed scope and description of work covered under this package has been specified in relevant clauses of Part-A of Technical specifications.