Design Information Length b Breadth c Depth a Volume d Weight of water Weigth of moist soil
7 7 5.5 269.5
m m m m3
1000 kg/m3 15.71 kN kN/m3
fc
ft ft ft ft3 in lb/ft3 lb lb/ft3
4000.0 psi 6000 60000.0 0.0 psi psi
Wall thickness
18.0 in
Water pressure Ratio b/a c/a Design for shear forces For b/a Bottom edge - midpoint Side Edge - maximum Side edge - midpoint
23.0 23.0 18.0 9517.2 18.0 62.4 100.0
624.3 lb/ft 1.27 1.27
0.36 0.25 0.25
1.25 1.25
For b/a = 1.25 Bottom edge - midpoint Side Edge - maximum Side edge - midpoint
0.36 0.25 0.25
Check shear at the bottom of the wall Maximum shear coeffiecents, Cs Maximum shear coeffiecents, Cs
0.36 long wall 0.36 short wall
1. Check shear at bottom of the wall Shear force, V
V Vu d Vc fVc
If fVc > Vu 2. Check shear at side edge of long wall V Vu
Shear in short side wall: V Nu Ag
Vc fVc
If fVc > Vu
4055.3 6894.1 15.7 23830.9 20256.3 OK
lbs lbs in lbs lbs
2816.2 lbs 4787.6 lbs
2816.2 lbs -4787.6 lbs 216.0 in1
22774.5 lbs 19358.3 lbs OK
Design for vertical bending moments(determine vertical steel
Reference
Calculations
Output
DESIGN OF EQUALIZATION BASIN
Exposure Conditions BS 8110 Severe exposure BS 8007 Design crack width 0.2 mm Material Concrete grade 35 A Steel grade 460
Concrete strength:
Table 2.3 Characteristic yield proof stress, fy pg 18 Partial factor of safety Materials Concrete 1.5 Steel 1.15 Loads Water Soil
1.4 1.4
35.00 N/mm2 460 N/mm2
Reference
Calculations
Output
LIMIT STATE DESIGN Cantilever Wall Consider 1m length of wall Design a cantilever wall to withstand water pressure Height H 5.5 m Normal Height of wate 5m Water Wg 10 kN/m3 Partical safety factors:Service limit state, g f Table 21 1.4 Ultimate limit state, g f 1 Service moment at roote of cantilever 208.3 kNm/m Ultimate moment, M 388.2 kNm/m From design charts the estimated root thickess h 700 mm Table 3.1 T 20 100 bar spacing (mm) able A.2.12 Limiting moment Ms 396.1 kNm Service steel stress fs 222 N/mm2 Ultimate shear capcity 363 kN/m For Ms
388.2083 ,fs
217.6 N/m2
Ok Using the values obtained from the design tables a check on the accuracy of the orignal assumption must be now made. cover 40 T
T 16 distribution steel
1625.00
Reference
Calculations
Output
Cover, c 40 R1 16 R2 20 Effective depth,d 650 Table 2 M/bd2 0.92 BS 8110 -3 100As/bd 0.25 As 1625.00 Ultimate limit state For ulitmate limit state, recall M 388.21 The Ultimate moment of resistance based on the steel is given by
mm mm mm mm
mm2 kNm/m
= 0.157
Maximum, Mu 2321.638 kNm/m If the Design Ultimate moment < Maximum Ultimate Moment then it is satisfactory
atisfactor
The ultimate moment of resistance based on the steel is given by: = 0.87 z
Depth of neutral axis,x
=
1−
1 − 0.7
/0.9
pg 43 Eq 7 x= = 0.06705 d Where the lever arm , = − 0.45 But maximum value is 0.95d zmax = 0.95 Mu (ultimate moment of resistance)
43.6 0.97 630 617.5
mm d mm mm
401.6 kNm/m
This section is therefore satisfactory as the applied ulitmate momment is less than the moment of resistance of the section Ultimate shear force at root of wall, V V BS8110 3.4.5.2
Therefore design shear stress,v = V/b vd
211.75 0.33
kN/m
Use atisfactor
Reference
Calculations 100
Output
0.25
Table 3.8 Design concrete shear stress,Vc (see Table 3.8) by interpolation Effective depth 0.25 0.25 0.50
0.40 vc 0.50
Gradient
0.4
vc 0.4 This is satisfactory and no shear stee is necessary. ote: s s ear stress s sat s actory at t e root o wa , t s not necessary to consider the critical secion of a height 2d above root.
Limit State of Cracking Service moment, Ms Section 3.4
208.3 kNm
Depth of neutral axis (elastic no-tension theory)
=
1+
2
− 1
Table 3.4 Modular ratio, ae = Es/Ec 15 pg 40 Where Es - modulus of elasticity of concrete, Es modulus of elasticity of steel
=
Therefore
0.0025
0.0375
Depth of neutral axis is given by And x =
x/d
Lever arm z = d-x/3
0.238917 155.30 mm 598.2 mm
Moment of resistance of section =
Therefore fs
214.3 N/mm2
Statisfactor
Reference
Calculations
BS 8007 Check steel and concrete service stress App B fs 214.3057 B2 0.8fy 368 Fcb 2Ms/zbx 4.484945 0.4fcu 15.75
Output
N/mm2 N/mm2 N/mm2 N/mm2
fcb<0.45fu Ok fs<0.8fy Ok
Ok Ok
Elastic strain at surface = e1
=
ℎ− −
×
200 kN/mm2
Es
0.00118
(ℎ − )(ℎ − ) 3 ( − )
e2
0.000615
Average surface strain em =e1 -e2
0.000565
Crack width w =
Recall bar spacing,s c bar size,f Ca = cmin+ f/2 acr
3 − 1 + 2 ( ) ℎ−
100 56 20 66
mm mm mm mm 72.80097 mm
Threrfore surface crack width,w Allowable w
0.116165 mm 0.2 mm 0.4
0.55 Cantilever wall 0.6
0.7 0.85 A
1 3.5
2.5
0.116165 atisfactor
Reference
Calculations
Output
Wall Footing Water pressure Soil pressure Surage Roof load Dead Load only
10.00 h 0.50 h 0 24 kN/m3
Case 1 Tank full Taking moments about A Restoring forces/ water 99 wall 92.4 Base
71.4
0.36 12.6 275.76 kN/m
Soil
Moments about A 311.85 117.81 124.95 0.216 6.3 561.126 kNm/m
Overturning Moment, =
1 6
561.126 kNm/m 277.2917 kNm/m 283.8343
Factor safety against over turning Case2 Tank empty Factor safety against over turning Footing reinforcment Soil pressure under base Calculate moment about centre line of base Case1 Mc Soil pressure 78.78857 +/Soil pressure Footing Reinforcement Moment at root of toe
2.023595
Safe
2.251023
Safe
-198.746 -81.1207 159.9093 kN/m2 2.332109 kN/m2 -65.315 kN/m/m
55 17 114.8872
Reference
Calculations
Moment root of heel
Output
63.95095 kN/m/m
By inspection not critical Heel reinforcement M Mu
63.95095 kN/m/m 1.4xM 89.53133 kN/m/m h 800 d 736 x1 0.026542 z = 1-0.45x 0.988056 But maxiumum value z is 0.95 Ast
228.5433 mm2
83.37178
Reference
Calculations
Output
Tank Floor Slab
Assuming uniform ground conditions, the floor slab is uniformly loaded and has no tranverse bending stresses. To proivide a reasonable thickness of concrete, and allowing for possible construction tolerances (crack tolerances) Use Critical steel ratio rcrit = fct/f y Where: fct =Tensile stress in concrete
To proivde a resaonable thickness of concret and allowing rcrit = fct/fy 1.6/460
200 mm thick
200 mm thick 0.003478
Provie top reinforcment only based on a surface zone 100 mm that is (one half of slab depth) As = 0.35% x 100 x1000 347.8261 mm2/m Use a welded mesh fabric with 10 mm wires in each direction at 200 mm spacings (393) Bottom zone does not require r einforcment
