SALIENT TECHNICAL FEATURES:
The proposed ash dyke area is contiguous to the stage-I ash dyke area. The topography of
the proposed ash dyke area is varying from RL 41.00M to RL 42.50M. Provision of rip rap is
envisaged on the dyke slope which is towards pond, nallah crossing and habitation. The total
length of the starter dyke is estimated to be about 5.5 km. To cater 25 years of ash storage,
two lagoons of starter dyke with 2 raising of 3M each (to be subsequently done with deposited
pond ash) is envisaged. However, raisings are not included in the scope of this package. The
maximum height of starter dyke and divide bund to be constructed with earth is about 8.50m.
It is also envisaged to provide bentonite blended soil layer of 300mm thickness in the storage
lagoons and over flow lagoon. Construction of two well type water escape structure with
flexible opening is also envisaged for decanting water from storage lagoon to over flow lagoon.
Construction of spillways is also envisaged for discharging excess rain water from storage
lagoons to OFL and from OFL to the existing drainage.
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:
1. Earth work in Embankment Construction = 13,50,000 cum
2. Excavation = 1,00,000 cum
3. Providing sand filter = 2,40,000 cum
4. Providing Aggregate filter = 24,000 cum
5. Providing Rock toe, rip rap etc = 24,000 cum
6. Dry Brick packing = 70,0000 SqM
7. RR Masonry = 4,200 cum
8. Concrete work (PCC& RCC) = 2,800 cum
9. Hume Pipe (100mm dia) = 1,050 m
10. Impervious Liner = 1,90,000 cum
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 with earth.
vi. Formation of chimney and blanket filter.
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.
x. Construction of dyke slope drains, kerb wall &, Steps on D/s Slopes.
xi. Providing Bentonite blended clay liner in storage lagoons and over flow lagoon(OFL).
xii. Construction of RCC works for water escape structures, Hume pipe cross drainage
through bituminous inspection roads, RCC peripheral Drain & RCC Spillways.
xiii. Laying and embedding RCC/MS pipes.
xiv. WBM Road works on top of dyke of inner divide dykes and bituminous roads on top of
outer dykes & all along the periphery of starter ash dyke.
xv. Diversion & training of existing natural Nallah including excavation and stone pitching (if
any).
xvi. Installation of instruments for monitoring purpose.
