ANNULAR PILE CAP DESIGN OF Sarenga PWSS - 8
ANNULAR PILE CAP DESIGN OF Sarenga PWSS - 8
ANNULAR PILE CAP DESIGN OF Sarenga PWSS - 8
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3 Q3 0.41 -28 (-28) x (-278.90) = + 7809.2
4 R1 0.65 -23.5 (-23.5) x (925.56) = -21750.66
Total Moment (Kn) = -5273.38
Now,
Radial moment at outer edge (Mrβ1) = (- 10014.68 x 4.25) / 100 = (-) 425.63 KN-m/m. and
Radial moment at inner edge (Mrα) = (- 5273.38 x 4.25) / 100 = (-) 224.12 KN-m/m.
As in reality, this inner edge is a free edge. For an annular raft apply equal and opposite moment
in the inner surface. The sum of the two effects will give the final value.
Now, applying an equal and opposite moment, Mα at f = α, the radial moment at f = β is:
𝛼 2 (1 − 𝑓 2 )
𝑀𝑟𝛽2 = 𝑀𝑟𝛼 𝑥 2 𝑥
𝑓 (1 − 𝛼 2 )
So, Radial Moment, Mrβ2 = (-224.12) x (0.1089/0.442) x ( 0.558 / 0.891) = -34.59 Kn-m/m
Now, Design radial Moment (Mrβ ) = Mrβ1 + Mrβ2 = 460.22 Kn-m/m
Sl.
Position Radius (m) Calculation β value
No.
1 Outer Pile Line 5.9 5.9/6.4 0.93
2 Middle Pile Line 4.25 4.25/6.4 0.65
3 Inner Pile Line 2.6 2.6/6.4 0.41
4 Column Line 4.25 4.25/6.75 0.65