Project:
CONSTRUCTION OF 200 CUBIC METRES R. C RECTANGULAR ABOVEGROUND
WATER TANK FOR RUBBER ESTATES NIGERIA LTD. ARAROMI - OBU, ODIGBO
LOCAL GOVERNMENT AREA, ONDO STATE - NIGERIA.
Consultant:
Page :
Job No.: RENL / RCWT / 2024
Prepared by : Engr. Omar Ngura
Subject: R. C RECTANGULAR ABOVEGROUND WATER STRORAGE TANK
Checked by : Engr. Niyi Folayan
Structure: CONCRETE STRUCTURES
Date: May, 2024
CALCULATIONS
ITEM
OUTPUT
INPUT DATA
WORKING CAPACITY:
200 M3
LENGTH (L):
9.60 M
BREADTH (B):
9.60 M
HEIGHT (H):
2.40 M
FREE BOARD:
0.20 M
MATERIAL STRENGTHS
Concrete grade, fcu
=
20 N/mm2
Steel bar characteristic strength, fy
=
415 N/mm2
Concrete characteristic strength
=
24 KN/m2
Soil Bearing capacity
=
100 KN/m3
2. PERMISSIBLE STRESSES
σcb
σst
σst
=
=
=
7 N/mm2
150 N/mm2 (on faces near water face)
190 N/mm2 (on faces away from water face)
Near Water
Face
E cm = 27.433
Es
=
Away from
Water Face
E cm = 27.433
200
m
=
7.290
m
= 7.290
j
=
0.872
j
= 0.890
Q
=
1.170
Q
= 1.030
R
=
1.00
<
2.00
The top portion of the side walls will be designed as a continuous structural member
while the bottom part, 1 m or H / 4 whichever is more will be designed as cantilever.
H/4 =
0.600 m <
1.0 m, Hence bottom 1m will be designed as cantilever.
Designing height = 1.000 m
Water pressure at 1.400 m height from the top of cant. member =
Water pressure at 2.400 m height from the bottom =
23.54 kN/m2
Page 1 of 6
13.73 kN/m2
Project:
CONSTRUCTION OF 200 CUBIC METRES R. C RECTANGULAR ABOVEGROUND
WATER TANK FOR RUBBER ESTATES NIGERIA LTD. ARAROMI - OBU, ODIGBO
LOCAL GOVERNMENT AREA, ONDO STATE - NIGERIA.
Consultant:
Structure: CONCRETE STRUCTURES
CALCULATIONS
OUTPUT
3
(Unit weight of water used = 9.81 kN/m )
2.40
9.60
13.734 kN/m2
23.54 kN/m2
TANK ELEVATION.
9.60
E
B
9.60
A
D
C
TANK G.A PLAN.
FIXED END MOMENTS:
MAB
=
105.5 kNm
MAD
=
-105.5 kNm
A A
D
9,600
Checked by : Engr. Niyi Folayan
Date: May, 2024
ITEM
Mmt.
Job No.: RENL / RCWT / 2024
Prepared by : Engr. Omar Ngura
Subject: R. C RECTANGULAR ABOVEGROUND WATER STRORAGE TANK
F
Page :
B
9,600
0
0.25 0.25
0
0
-105.48 105.48
0
0
0.00 0.00
0
0
0.00 0.00
0
0
-105.48 105.48
0
Page 2 of 6
Project:
CONSTRUCTION OF 200 CUBIC METRES R. C RECTANGULAR ABOVEGROUND
WATER TANK FOR RUBBER ESTATES NIGERIA LTD. ARAROMI - OBU, ODIGBO
LOCAL GOVERNMENT AREA, ONDO STATE - NIGERIA.
Consultant:
Page :
Job No.: RENL / RCWT / 2024
Prepared by : Engr. Omar Ngura
Subject: R. C RECTANGULAR ABOVEGROUND WATER STRORAGE TANK
Structure: CONCRETE STRUCTURES
Checked by : Engr. Niyi Folayan
Date: May, 2024
CALCULATIONS
ITEM
MAB
=
105.48 kNm
MAD
=
-105.48 kNm
Moment at centre of long span wall AB=
52.74 kNm
Moment at centre of long span wall AD=
52.74 kNm
Direct tension in long wall (AB)=
65.92 kN
Direct tension in long wall (AB)=
65.92 kN
OUTPUT
DESIGN OF LONG WALLS:
At support:
Mmt. = 105.48 kNm
T =
65.92 kN
Tension on Lquid factor
From Table 9-6
Q =
0.306 Assuming d/D=
0.9
D =
587.1 mm
=
Say D
Concrete cover =
25 mm
Assumed Reinf't.=
20 mm
d =
600 mm
565 mm
From Table 9-5
Ast1 for moment =
1427.3 mm2
Ast2 for direct tension =
Total (Ast1 + Ast2) =
439.5 mm2
1866.7 mm2
Provide 20 mm Diameter High tensile bar
168.31 mm
Spacing of bar =
Provide 20 mm Diameter High tensile bar @ 150mm c/c …marked (a) =
At Centre
M
=
52.7 kNm
T
=
65.9 kN
e
=
0.8 m
Tension on remote face
Page 3 of 6
2,094 mm2/m
Project:
CONSTRUCTION OF 200 CUBIC METRES R. C RECTANGULAR ABOVEGROUND
WATER TANK FOR RUBBER ESTATES NIGERIA LTD. ARAROMI - OBU, ODIGBO
LOCAL GOVERNMENT AREA, ONDO STATE - NIGERIA.
Consultant:
Page :
Job No.: RENL / RCWT / 2024
Prepared by : Engr. Omar Ngura
Subject: R. C RECTANGULAR ABOVEGROUND WATER STRORAGE TANK
Checked by : Engr. Niyi Folayan
Structure: CONCRETE STRUCTURES
Date: May, 2024
CALCULATIONS
ITEM
E
=
535 mm
Modified moment
=
35.27 kNm
Ast1 for moment =
369.1 mm2
Ast2 for direct tension =
Total (Ast1 + Ast2) =
439.5 mm2
OUTPUT
808.6 mm2
Provide 16 mm Diameter High tensile bar
248.68 mm
Spacing of bar =
Provide 16 mm Dia. Ht bar @ 200mm c/c …marked (b) =
From Table 9-3: Minimum reinforcement =
Distribution steel =
960 mm2
On each face =
480 mm2
1,005 mm2/m
0.16 %
Provide 12 mm Diameter High tensile bar
235.65 mm
Spacing of bar =
Provide 12 mm Dia. Ht bar @ 200mm c/c …marked (d) =
565 mm2/m
Vertical Steel (c)
Provide 12 mm Diameter High tensile bar
235.65 mm
Spacing of bar =
Provide 12 mm Dia. Ht bar @200mm c/c both faces (c)=
565 mm2/m
Horizontal Steel
Remote face (b):
Provide
16 mm Dia. Ht bar @ 200mm c/c …marked (b) = 1,005 mm2/m
Liquid face (d):
Provide
12 mm Dia. Ht bar @ 200mm c/c …marked (d) =
565 mm2/m
Vertical Steel (c):
Provide
12 mm Dia. Ht bar @200mm c/c both faces (c)=
565 mm2/m
DESIGN OF SHORT WALLS:
At support:
Mmt. =
T =
105.48 kNm
65.92 kN
Tension on Lquid factor
Page 4 of 6
Project:
CONSTRUCTION OF 200 CUBIC METRES R. C RECTANGULAR ABOVEGROUND
WATER TANK FOR RUBBER ESTATES NIGERIA LTD. ARAROMI - OBU, ODIGBO
LOCAL GOVERNMENT AREA, ONDO STATE - NIGERIA.
Consultant:
Page :
Job No.: RENL / RCWT / 2024
Prepared by : Engr. Omar Ngura
Subject: R. C RECTANGULAR ABOVEGROUND WATER STRORAGE TANK
Checked by : Engr. Niyi Folayan
Structure: CONCRETE STRUCTURES
Date: May, 2024
CALCULATIONS
ITEM
OUTPUT
From Table 9-5
Ast1 for moment =
1427.3 mm2
Ast2 for direct tension =
Total (Ast1 + Ast2) =
439.5 mm2
1866.7 mm2
Provide 20 mm Diameter High tensile bar
168.31 mm
Spacing of bar =
Provide 20 mm Diameter High tensile bar @ 150mm c/c …marked (b) =
2,094 mm2/m
At Centre
M
=
52.74 kNm
T
=
65.92 kN
From Table 9-5
Ast1 for moment =
Tension on liquid face
713.6 mm2
Ast2 for direct tension =
Total (Ast1 + Ast2) =
439.5 mm2
1153.1 mm2
Provide 16 mm Diameter High tensile bar
Spacing of bar =
174.39 mm
Provide 16 mm Dia. HT bar @ 150mm c/c …marked (e) =
From Table 9-3: Minimum reinforcement =
Distribution steel =
960 mm2
On each face =
480 mm2
1,340 mm2/m
0.16 %
Provide 12 mm Diameter High tensile bar
Spacing of bar =
235.65 mm
Provide 12 mm Dia. HT bar @ 200mm c/c …marked (d) =
2
565
mm /m
565
mm /m
Vertical Steel (c)
Provide 12 mm Diameter High tensile bar
Spacing of bar =
235.65 mm
Provide 12 mm Dia. HT bar @ 200mm c/c both faces (c)=
Page 5 of 6
2
Project:
CONSTRUCTION OF 200 CUBIC METRES R. C RECTANGULAR ABOVEGROUND
WATER TANK FOR RUBBER ESTATES NIGERIA LTD. ARAROMI - OBU, ODIGBO
LOCAL GOVERNMENT AREA, ONDO STATE - NIGERIA.
Consultant:
Page :
Job No.: RENL / RCWT / 2024
Prepared by : Engr. Omar Ngura
Subject: R. C RECTANGULAR ABOVEGROUND WATER STRORAGE TANK
Structure: CONCRETE STRUCTURES
Checked by : Engr. Niyi Folayan
Date: May, 2024
CALCULATIONS
ITEM
OUTPUT
Horizontal Steel
Remote face (e):
Provide
16 mm Dia. HT bar @ 150mm c/c …marked (e) =1,340 mm2/m
Liquid face (d):
Provide
12 mm Dia. HT bar @ 200mm c/c …marked (d) = 565 mm2/m
Vertical Steel (c):
Provide
12 mm Dia. HT bar @ 200mm c/c both faces (c)= 565 mm2/m
BOTTOM 1M WILL BE DESIGNED AS CANTILEVER
Cantilever moment:
M
=
3.92 kNm
From Table 9-5
Ast1 for moment =
53.1 mm2
From Table 9-3: Minimum reinforcement =
0.16 %
2
Distribution steel =
960 mm
On each face =
480 mm2
Provide 12 mm Diameter High tensile bar
Spacing of bar =
235.65 mm
Provide 12 mm Dia. High tensile bar @ 200mm c/c each face …marked (c) =
565 mm2/m
BASE SLAB:
Base slab is resting on ground. For a water head
For a
2.40 m water head, provide
150 mm thick slab
From Table 9-3: Minimum reinforcement = 0.229 %
Min. steel =
344 mm2 ( 171.8 mm2 bothways)
Provide 10 mm Diameter High tensile bar
Spacing of bar =
457.35 mm
Provide 10 mm Dia. High tensile bar @ 200mm c/c both ways, T & B =
Page 6 of 6
393 mm2/m