Numerical problem , single ,group pile capacity (usefulsearch.org) (useful search)

1. SOLUTION:-
Qa = WH/ 6(S+C)
WHERE W= 20 KN, H= 1*100= 100CM
S= 0.5 CM , C= 2.5 CM
Qa= 20* 100 /6(0.5+ 2.5)=
=111.1 KN/m2

2. Q:-10 In a 16 pile group the pile diameter is 45cm and center to
center spacing of the square group is 1.5m if c=50kN/M²,
determine whether the failure would occur with the pile acting
individually or as a group? Neglect bearing at the tip of the pile.
All the pile are 10m long. Take m=0.7 for shear mobilization
around each pile..
 Solution:- given , n = 16, d=45cm , l= 10 m , b= (150*3)+ 45=4.95 m
1. For the group of piles, Qg= c* perimetre*l=c* 4b *l
=50x4x4.95x10= 9900 kN
2. For the pile acting individually, Qg= n(mAp)
Qg= 22x45x10/7=7917kN
 Which is less than group pile and the foundation will fail by the pile
acting individaully and load at failure would be 7917kN.