(2) footing design
TRANSCRIPT
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FOOTING DESIGN PROGRAMME USING LIMIT STATE METHOD
S = 300 260.87
C = 20 fcd=0.85*fck/1.5 9.07
0.90
= 0.5fctd(1+50*rho) = 672.90
Allowable bearing pressure, s (KPa) 200
= 0.25fctd(1+50*rho) = 336.45
3.00
18.00
Column width, a (m) 0.30
Footing Group F1
229.00
Footing Dimension, L * L (m) 1.50 1.50
2.25
Depth, D (m) 0.25
Effective depth, d (m) = D - 0.05 = 0.20
Own Weight of Footing, Wc (KN) = 18.28
Soil Weight , Ws(KN) = 144.79
= Ps+Wc+Ws = 392.07 174.25
Checking Bearing Capacity = 174.25
Punching Shear, Vp (kN) = 203.56
Punching Shear Stress, Vup (KPa) = 508.89
= 40.71
= 203.56
= 18.32
N = 0.051
B 1 -(1 - 2*N)^0.5 0.052
As B*fcd*b*d/fyd 360.48
Asmin 0.5/fyk*b*d 333.33
Asing (3.14*d^2/4) 12.00 113.14
Spacing for As Asig*1000/As 313.87
Spacing for Asmin Asig*1000/Asmin 339.43
Final use 812 c/c 240
Take rho = rmin
= 0.002
fctd = 0.21*((fck)^0.67)/1.5=
Allowable punching resistance of
concrete, Vup(KPa)
Allowable wide beam shear
resistance of concrete, vud
(KN/m2)
Foundation depth, fd
(m)
Unit weight of soil, gs (KN/m3)
Super-structural load, Ps(KN)
Footing Area, A(m2)
=1.3*Af*d*g
s
= 1.3*Af*(f
d-D)*g
s
Total load on footing, PT (KN)
= PT/A
=Ps*(1-((a+d)/L)^2)
= Vp/(4(a+d)*d)
Wide beam Shear, Vw
(KN) = Ps/A
f(L/2-d-a/2)
Wide beam Shear stress Vuw(KN/m2) = Vw/(b*d)
Design Moment, Md (KN-m/m)
= (Ps/A
f)*((L-
a /2 ^2*0.5= (M
d*10E+6/f
cd*b*d^2)
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FOOTING DESIGN PROGRAMME USIN
S = 300
C = 25
1.04
= 0.5fctd(1+50*rho)
200
= 0.25fctd(1+50*rho)
1.50
18.00
Column width, a (m) 0.30
Footing Group F2
390.00
Footing Dimension, L * L (m) 1.60
2.56
Depth, D (m) 0.30
Effective depth, d (m) = D - 0.05
Own Weight of Footing, Wc (KN)
Soil Weight , Ws(KN)
= Ps+Wc+Ws
Checking Bearing Capacity
Punching Shear, Vp (kN)
Punching Shear Stress, Vup (KPa)
= Ps/Af(L/2-d-a/2)
Take rho = rmin
= 0.002
fctd
= 0.21*((fck
)^0.67)/1.5=
Allowable punching resistance ofconcrete, Vup(KPa)Allowable bearing pressure, s(KPa)
Allowable wide beam shearresistance of concrete, v
ud
(KN/m2
)Foundation depth, f
d(m)
Unit weight of soil, gs(KN/m3)
Super-structural load, Ps
(KN)
Footing Area, A(m2)
=1.3*Af
*d*gs
= 1.3*Af*(f
d-D)*g
s
Total load on footing, PT
(KN)
= PT/A
=Ps*(1-((a+d)/L)^2)
= Vp/(4(a+d)*d)
Wide beam Shear, Vw
(KN)
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= Vw/(b*d)
N
B 1 -(1 - 2*N)^0.5
As B*fcd*b*d/fyd
Asmin 0.5/fyk*b*d
Asing (3.14*d^2/4) 14.00
Spacing for As Asig*1000/As
Spacing for Asmin Asig*1000/Asmin
Final
Wide beam Shear stress Vuw(KN/
Design Moment, Md
(KN-m/m) = (Ps/Af)*((L-a)/2)^2*0.5
(Md*10E+6/fcd*b*d^2
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LIMIT STATE METHOD
260.87
fcd=0.85*fck/1.5 11.33
= 781.41
= 390.71
1.60
= 0.25
= 24.96
= 71.88
= 486.84 190.17
= 190.17
= 343.92
=625.30
= 60.94
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= 243.75
= 32.18
= 0.045
0.047
505.22
416.67
154.00
304.82
369.60
se 714 c/c 300
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FOOTING DESIGN PROGRAMME USING LIMIT STATE METHO
S = 300 260.87
C = 25 fcd=0.85*fck/1.5 11.33
1.04
= 0.5fctd(1+50*rho) = 781.41
200
= 0.25fctd(1+50*rho) = 390.71
1.50
18.00
Column width, a (m) 0.30
Footing Group F3
310.00
Take rho = rmin
= 0.002
fctd
= 0.21*((fck
)^0.67)/1.5=
Allowable punching resistance ofconcrete, Vup(KPa)Allowable bearing pressure, s(KPa)
Allowable wide beam shearresistance of concrete, v
ud
(KN/m2)
Foundation depth, fd
(m)
Unit weight of soil, gs(KN/m3)
Super-structural load, Ps(KN)
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Footing Dimension, L * L (m) 1.40 1.40
1.96
Depth, D (m) 0.25
Effective depth, d (m) = D - 0.05 = 0.20
Own Weight of Footing, Wc (KN) = 15.93
Soil Weight , Ws(KN) = 57.33
= Ps+Wc+Ws = 383.26
Checking Bearing Capacity = 195.54
Punching Shear, Vp (kN) = 270.46
Punching Shear Stress, Vup (KPa) = 676.15
= Ps/Af(L/2-d-a/2) = 55.36
= Vw/(b*d) = 276.79
= 23.92
N = 0.053
B 1 -(1 - 2*N)^0.5 0.054
Footing Area, A(m2)
=1.3*Af*d*g
s
= 1.3*Af*(f
d-D)*g
s
Total load on footing, PT
(KN)
= PT/A
=Ps*(1-((a+d)/L)^2)
= Vp/(4(a+d)*d)
Wide beam Shear, Vw
(KN)
Wide beam Shear stress Vuw(KN/
Design Moment, Md
(KN-m/m) = (Ps/Af)*((L-a)/2)^2*0.5
(Md*10E+6/fcd*b*d^2
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As B*fcd*b*d/fyd 471.29
Asmin 0.5/fyk*b*d 333.33
Asing (3.14*d^2/4) 14.00 154.00
Spacing for As Asig*1000/As 326.76
Spacing for Asmin Asig*1000/Asmin 462.00
Final use 614 c/c 300
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195.54
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FOOTING DESIGN PROGRAMME USIN
S = 300
C = 25
1.04
= 0.5fctd(1+50*rho)
200
= 0.25fctd(1+50*rho
1.50
18.00
Column width, a (m) 0.30
Footing Group F4
210.00
Footing Dimension, L * L (m) 1.20
1.44
Depth, D (m) 0.20
Effective depth, d (m) = D - 0.05
Own Weight of Footing, Wc (KN)
Soil Weight , Ws(KN)
Take rho = rmin
= 0.002
fctd
= 0.21*((fck
)^0.67)/1.5=
Allowable punching resistance ofconcrete, Vup(KPa)Allowable bearing pressure, s
(KPa)Allowable wide beam shearresistance of concrete, v
ud
(KN/m2)
Foundation depth, fd
(m)
Unit weight of soil, gs(KN/m3)
Super-structural load, Ps(KN)
Footing Area, A(m2)
=1.3*Af*d*g
s
= 1.3*Af*(f
d-D)*g
s
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= Ps+Wc+Ws
Checking Bearing Capacity
Punching Shear, Vp (kN)
Punching Shear Stress, Vup (KPa)
= Ps/Af(L/2-d-a/2)
= Vw/(b*d)
N
B 1 -(1 - 2*N)^0.5
As B*fcd*b*d/fyd
Asmin 0.5/fyk*b*d
Asing (3.14*d^2/4) 14.00
Spacing for As Asig*1000/As
Spacing for Asmin Asig*1000/Asmin
Final
Total load on footing, PT
(KN)
= PT/A
=Ps
*(1-((a+d)/L)^2)
= Vp/(4(a+d)*d)
Wide beam Shear, Vw
(KN)
Wide beam Shear stress Vuw(KN/
Design Moment, Md
(KN-m/m) = (Ps/Af)*((L-a)/2)^2*0.5
(Md*10E+6/fcd*b*d^
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G LIMIT STATE METHOD
260.87
fcd=0.85*fck/1.5 11.33
= 781.41
= 390.71
1.20
= 0.15
= 9.36
= 43.80
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= 263.16 182.75
= 182.75
= 180.47
= 668.40
= 43.75
= 291.67
= 14.77
= 0.058
0.060
388.95
250.00
154.00
395.94
616.00
se 514 c/c 350