5 STOREY COMMERCIAL

DELIRO ENGINEERING DESIGN SERVICES Project BUILDING WITH BASEMENT

ECC. PAD BASE CALCULATIONS
Client Made by Date Job No
FOOTING F5 AND 1-2-25 1
Description
tel & fax nos ---- & ------ COMPUTATIONS Checked Revision Page No
Originated from © 2003 mohamed salah Elsheikh AUTH. Copy - - -
Design of R.C. Eccentricity loaded pad base according the BS8110
take
fcu fy Col. Size ( cm ) Load ( Pu ) S.B.C. ( q all ) M1 M2
2 2 2
( N/mm ) ( N/mm ) length ( ac ) width ( bc ) ( ton ) ( KN/m ) m.t m.t
21 414 40 40 187.875 160 172.8 172.8

punch at sec 2-2 of shear at 2 M1 = 172.8m M 2 172.8 m

1.5d d .t = .t
187.875 187.875

sec 1-1 of shear at a

3.00

d c
b B
1 c
1
6.00
L 2 L B

1.88 21.08 1.88 21.08

e max Select Footing dimension ( m )
Z
Length ( L ) width ( B ) depth ( d ) quick report
(m) 6.00 3 0.4 3 ( Half of footing at Critical
(m )
Area, hence use 6.0x 6.0M
0.92 Dimension ( OK . ) 18.00 for F5) PUNCH UNSAFE

e < L/6 ( OK . ) TRUE

SHEAR SAFE
Y 12 Y 16 Y 20
AREA OF STEEL Use
cm2 cm2 cm2
M 1-1 (m.t) 212.79 No. of bars / m 2521 1417 907
Total As req. 17087.98 act. As 17088.99 17089.02 17091.02
 M 2-2 (m.t) 92.82 No. of bars / m 2009 1130 723
Total As req. 6810.83 act. As 6811.64 6811.89 6813.80

Check punching shear

punching is checked on a perimeter ( 1.5 d ) = 60 cm from the column face
The stress is checked on the most heaviest loaded side
Direction 1 - 1
perimeter = 1600 mm v (shear stress) = 1.67 N/mm2
shear = 1066.7 KN
Direction 2 - 2
perimeter = 1600 mm punching shear unsafe
shear = 560.8 KN
increase d or As
v (shear stress) = 0.876 N/mm2
Concrete shear stress
vc = 1.529 N/mm2 FALSE
check max shear stress at face of column
perimeter = 400.00 mm ( v ) all. Max (N/mm2) =
shear = 91.93 KN 3.666
v (shear stress) = 0.575 N/mm2
SAFE ( at col. Face )
check vertical shear

the critical section at ( d ) from the column face

Direction 1 - 1
v = 1241.37 KN
v (shear stress) = 1.03 N/mm2
SAFE

Direction 2 - 2 TRUE
v = 982.87 KN
v (shear stress) = 0.82 N/mm2
SAFE
 design of R.C. sections according the BS8110
For M 1-1
fcu (N/mm2) fy b (cm) d (cm) MU ( m.t ) M1-1 ( m.t )
21 414 600 40 314.50 212.79

From above the Sec. is Singly reinforced

For M 2-2
fcu (N/mm2) fy b (cm) d (cm) MU ( m.t ) M2-2 ( m.t )
21 414 300 40 157.25 92.82

From above the Sec. is Singly reinforced

M1-1 ( m.t ) M2-2 ( m.t )

Singly reinforced Design Singly reinforced Design

k= 0.106 k= 0.046
Z final = 34.573 Z final = 37.837
As = 17,087.98 mm2 As = 6,810.83 mm2

check shear & punching

νc = ( 0.79*(100 As/bd)1/3* (400/d)1/4* (fcu/25)1/3 ) / γm

where :- γm = 1.25 & 400/d ≥ 1 & (100 As/bd) ≤ 3
FOR SEC 1 - 1
 100 As/bd 400/d νc N/mm2 ( v ) all. Max v max all. (N/mm2)

3.00 10.00 1.53 3.666 max of ( 0.8√ fcu , 5 )

FOR SEC 2 - 2
100 As/bd 400/d νc N/mm2 ( v ) all. Max v max all. (N/mm2)
3.00 10.00 1.53 3.666 max of ( 0.8√ fcu , 5 )

M1 =172.8 m M2 = 172.8 m
.t
187.875 .t 187.875

6.00 3

3.2 2.8 1.7 1.3

1.88 1.88
21.08 21.08
12.12 12.76

M 1-1 = 212.79 M 2-2 = 92.82

STRESS AT ( d ) FROM COL. FACE = STRESS AT ( d ) FROM COL. FACE =

13.40 2 15.32 2
ton / m ton / m

Q max ( 1 -1 ) = 124.14 ton Q max ( 2 - 2 ) = 98.29 ton

punch at 1.5d 0.7
A
B
2.2 The punching shear is checked
3 on a perimeter (1.5d) from col. Face
1.6 The stress is checked on AB,
which is the heaviest loaded side
B
1.6

6.00

At most heaviest side only At face of column

P1 = 1600 mm P1 = 400 mm
V1 = 1066.71 KN V1 = 80.4075 KN
v 1-1 = 1.67 N/mm2 v1 = 0.50 N/mm2

P2 = 1600 mm P2 = 400 mm
V2 = 560.76125 KN V2 = 91.9275 KN
v 2-2 = 0.88 N/mm2 v2 = 0.57 N/mm2