Public Works Department Tender

Construction of Recharge Pit for wells used for drinking Water supply under Campbell Bay Division at Little Nicobar.

Constuction of Cement concrete chamber of size 1.50m (L) X 1.50m (B) X 0.70m ( D) (Internal Dimensions) with open top for each recharge pit consisiting of following component of work:- i) 20 cm thick hollow wall of cement concrete 1:3:6 (1 Cement : 3 Coarse sand: 6 graded stone aggregate 12.5 mm nominal size) fixed with 1:6 cement mortar forming internal dimensions of 1.50m (L) X 1.50m (B) and wall finished with 12mm cement plaster of 1:3 (1 cement : 3 Fine sand) along with foundation base of Cement concrete 1:4:8 (1 Cement : 4 Coarse sand : 8 Graded stone aggregate 40mm nominal size) size 30cm wide and 15cm deep provided below the wall. ii) Providing and fixing 04 nos of RCC Manhole cover slab ( with perforations 25mm dia) of size 75cm X 75cm and 10cm thick for each recharge pit using reinforcement cement concrete of 1:1.5:3 (1 Cement : 1.5 Coarse sand: 3 graded stone aggregate 20 mm nominal size) including earthwork in excavation for upto required depth below GL and disposal of surplus earth complete within a lead of 50m and reinforcement work etc all complete as per the enclosed drawing and direction of Engineer-In-charge.

Construction of 01 nos of sqaure shaped recharge pit with sedimentaton pit of size 1.20m (L) X 1.20m (B) X 1.20m (H) with filter media consisiting of bottom most layer (1st Layer) 60cm deep with 22.5cm sized stone boulders, 2nd layer of 60cm deep filled with 63mm to 45mm, 53mm to 22.4mm, 22.4mm to 11.2mm sized stone aggregates each of 20cm deep respectively and top most layer of size 1.50m (L) X 1.50m (B) 30cm deep filled with coarse sand of size 1.50 to 2.00mm, full complete in graded from i/c laying of a impervious sheet) below the layer of Coarse Sand and earthwork in excavation for upto 1.75m depth below GL and disposal of surplus earth complete within a lead of 50m all complete as per the enclosed drawing and direction of Engineer In-charge.