DESIGN OF RECTANGULAR UNDER GROUND WATER TANK CLOSE OR OPEN FROM TOP 

DESIGN RESULT 
DESIGN OF RECTANGULAR UNDER GROUND WATER TANK CLOSE OR OPEN FROM TOP Height of Tank above GL in M (h1): 0.0 Depth of Tank below GL in M (h2): 2 Width of Base in M (W): 4 Length of Base Slab in M (L): 7 Tank Toe in M (b1): 0.3 Thickness of Stem at Top in M (t1): 0.15 Thickness of Stem at Base in M (t2): 0.45 Thickness of Base Slab in M (t3): 0.45 SBC at Depth " h2 " in T/M2: 10 Dia of Vertical Reinforcement: 12 Dia of Horizontal Reinforcement: 8 Concrete Grade: M30 Density of Soil in T/M3: 1.8 Steel Strength (fy) [N/MM2]: 415 Vertical Load From Roof Slab in T/M (V): 0.6 Unbalance Horizontal Load From Roof Slab in T/M (H): 0 Depth of Water Table (hw) below GL. in M: 0.0 Lateral Pressure Coefficient of Soil: 0.33  Total Max. Load of Tank in Tons = 265.74 Total Load of Tank From Roof Slab / Platform in Tons = 24.63 Total assumed Unbalance Horizontal Load on Tank From Roof (H*W) in Tons = 0 Maximum Pressure on Base in T/M2 = 3.6 Empty Load of Tank in Tons = 187.74 Uplift Force on Tank Bottom in Tons = 147.49 FOS against uplift = 1.27  Cantilever Stem BM on Water Face in tm = 0.62 Cantilever Stem BM on Soil Face in tm = 0.78 Cantilever Equivalent Stem BM on Water Face in tm = 1 Cantilever Equivalent Stem BM on Soil Face in tm = 1.16 Max. Stem SF in tons = 1.52 Max. Equivalent Horizontal Stem BM in tm = 0.46 Max. Vertical Stem Compression in tons = 2.18 Max. Horizontal Stem Tension in tons = 0.98  Equivalent Design Hogging BM in Base in TM = 1.96 Equivalent Sagging BM in Base in TM = 1.09 Tension in Base in Tons = 1.2 Compression in Base in Tons = 1.52 Max. Shear Force (SF) in Base in Tons = 1.34  Actual Tensile Stress in Stem in Kg/CM2 = 1.83 Permissible Tensile Stress in Stem in Kg/CM2 = 20  Provide Vertical Stem bars at Water Face as dia 12 MM @ 300 MM c/c Provide Vertical Stem bars Away from Water Face as dia 12 MM @ 300 MM c/c Provide Horizontal Stem bars at Each face as dia 8 MM @ 140 MM c/c  Factored Shear Stress in Stem in Kg/CM2 = 0.57 Max. Permissible Shear Stress in Stem in Kg/CM2 = 36.7 Capacity of Stem Section in Shear in Tons = 6.35  Permissible Bending Tension in Base Slab in Kg/CM2 = 20 Actual Tensile Bending Stress in Base Slab in Kg/CM2 = 6.43 Permissible Direct Tensile Stress in Base Slab in Kg/CM2 = 15 Actual Direct Tensile Stress in Base Slab in Kg/CM2 = 0.27 Ratio is < 1.0 = 0.34 Actual Bending Tensile Stress in Base when in Comp. in Kg/CM2 = 2.1  Provide Bothways Base Reinforcement at Water Face (Top) as dia 12 MM @ 209 MM c/c Provide Bothways Base Reinforcement at Bottom Face as dia 12 MM @ 209 MM c/c Factored Shear Stress in Base in Kg/CM2 = 0.5 Max. Permissible Shear Stress in Base in Kg/CM2 = 36.7 Capacity of Base Section in Shear in Tons = 7.51  Total Concrete Quantity Consumed by Tank in M3 = 52.27 Total Steel Quantity Consumed by Tank in Kg = 1988.57 Clear Cover to Reinforcement is taken as 40 MM : Load Factor = 1.5 For Construction Joint details refer Standards. Design Roof Slab (If reqd.) as per IS 456. Use Minimum M30 Grade Conc. The Applied Unbalance Load { H } if any shown on Top is from Roof Slab / Platform. ooooooooooooooooooo fini oooooooooooooooooooooooo 