PROJEK:
RENOVATION MUSA HOUSE
BAHAGIAN BAHAGIAN ST RUKTUR:
NO. RUJUKAN: RUJUKAN:
FOOTING
RUJUKAN LUKISAN:
1
MUKA:
DIKIRA OLEH: DISEMAK OLEH: RUJUKAN
TARIKH:
KIRAAN
HASIL
DESIGN OF CANTILEVER FOOTING (J4)
B.S 8110
x a oa stump,
=
190
kN
Characteristic strength of reinforcement, fy
=
460
N/mm
2
Characteristic concrete strength, fcu
=
30
N/mm
2
Cover of footing, C
=
40
mm
Diameter of bar size (assume)
=
12
mm
Thickness of footing, h
=
750
mm
Selfweight of footing (assume)
=
80
kN
Bearing pressure of soil
=
100
kN/m
+
80
v
2
Plan area of base Total load
=
190
=
270
Plan area of base
=
kN Total load Bearing pressure
=
270 100
=
2.7
Provi de 1.7m 1.7m x 1.7 1.7 m, area = b a s e i s 7 50 50 m m t h i c k n e s s .
selfweight footing
F
2
2
m a n d as as s u m i n g
=
l x b x h x density concrete
=
1.7m x 1.7m x 0.7m x 24kN/m
=
base
2.89 2.89
m
52.02
kN < 80 kN
Eccentric load, e l
=
len length of fou foundat dation ion
b
=
width dth of fou foundatio tion
F
=
tota totall load load on foun founda dati tion on (including weight of base)
F base
=
weight of base
3
ok
PROJEK:
NO. RUJUKAN:
BAHAGIAN ST RUKTUR: RUJUKAN LUKISAN:
2
MUKA:
DIKIRA OLEH: DISEMAK OLEH: RUJUKAN
B.S 8110
TARIKH:
KIRAAN
total load, F
HASIL
axial load stump, Fv + Fbase
= =
242.02
kN
242.02
kN
Fv = 190kN F= ew = 625
750mm 75 300 1700
a2
75 300
b =
l
a2
=
= =
e
=
1700
1700
1/2 ( l - a ) + e w 1325
mm
Fv ew + Fh h + M Fv + Fbase
which is more than l / 6 k
=
0.63
m
=
0.28
m
=
4 l 3 ( l - 2e )
=
5.18
thus
PROJEK:
NO. RUJUKAN:
BAHAGIAN ST RUKTUR: RUJUKAN LUKISAN:
3
MUKA:
DIKIRA OLEH: DISEMAK OLEH: RUJUKAN
BS 8110
TARIKH:
KIRAAN
HASIL
the maximum ground pressure are :
f max
=
kF b l
=
433.7
850
e= 630
2
kN/m
F
f base f1
f max
1700
f base
F base
=
bxl = f1
=
2
kN/m
18 f max - f
=
Net pressure, Np
base 2
415.7
kN/m
=
f1 x b
=
707
kN/m
moment, M Myy
Mxx
=
F 8b
2
( b - a )
=
34.88
kNm
=
a2 b
f2 +
2 =
161.15
a2 3l
kNm
( f1 - f2 )
PROJEK:
NO. RUJUKAN:
BAHAGIAN ST RUKTUR: RUJUKAN LUKISAN:
4
MUKA:
DIKIRA OLEH: DISEMAK OLEH: RUJUKAN
BS 8110
TARIKH:
KIRAAN
HASIL
Flexure Maximum moment, M Effective depth, d
=
161.15 =
h - C - dia. Bar/2
=
Clause 3.4.4.4
K
kNm
704
=
M fcu b d2
=
0.006
mm
<
0.156
so, compression reinforcement is not required Lever arm, z
so,
z
=
d ( 0.5 +
0.25 - K/0.9)
=
0.99
d
=
0.95
d
=
668.8
mm
Area steel required
Area steel minumum
>
0.95
=
M 0.87 fy z
=
602.1
=
0.13bh/100
=
975
Hence, provide T 16-175 Area = for main and secondary bars.
Shear Punching shear
critical perimeter
stump 1.5d
1149
mm
2
2
mm
2
mm /m
d
PROJEK:
NO. RUJUKAN:
BAHAGIAN ST RUKTUR: RUJUKAN LUKISAN:
5
MUKA:
DIKIRA OLEH: DISEMAK OLEH: RUJUKAN
TARIKH:
KIRAAN
stump size,
BS 8110
b d
critical perimeter, Cp
= =
=
=
9648
=
( 400 + 3d )
=
6.310
mm 2
6
x 10
x
2
mm
2.89
-
6.310
-1421.64 kN
Design punching shear stress, v
=
V / Cp x d -0.20931 N/mm
= Table 3.9
704
Np(area of base - area perimeter)
415.7
=
mm mm
4 x 300 + 8 x 1.5 x
Ultimated punching force, V = =
300 300
stump perimeter + 8 x 1.5d
=
Area within perimeter is
HASIL
2
Design concrete shear stress, Vc Vc
=
(100As/bd)
1/3
1/4
1/3
x (400/d) x (fcu/25) x 0.79 1.25
100As/bd
=
0.163
<
3
take
=
0.163
400/d
=
0.568
<
1
take
=
1.000
fcu/25
=
1.2
Vc
=
0.37
N/mm
2
Since Vc > v , 750mm depth of footing is acceptable
Ok
Maximum shear
Maximum shear occurs at face of column V max
=
N / column perimeter x d < permisible 0.8
=
190 x 10 4 x 300 x 504
=
3
0.225
<
2
N/mm
<
0.8
(fcu)
(30)
4.38178 N/mm
2
Ok
PROJEK:
NO. RUJUKAN:
BAHAGIAN ST RUKTUR: RUJUKAN LUKISAN:
6
MUKA:
DIKIRA OLEH: DISEMAK OLEH: RUJUKAN
BS 8110
TARIKH:
KIRAAN
HASIL
Force shear
1d
300
704 621
Ultimate shear force ( Uv )
Design shear stress
=
415.7
=
438.82
=
Uv / bd
=
0.367
x 1.7 x 0.621 kN
2
N/mm
Since Vc > v, no reinforcement shear is required
Ok
