PART ART III: III: PILE PILE GROP GROP
A. In!r"d#$!%"n & E'a(p)* "+ P%)* Gr"#p
Keywords: single footings, foundation walls, friction pile, end-bearing pile, footing
A. In!r"d#$!%"n & E'a(p)* "+ P%)* Gr"#p
Keywords: single footings, foundation walls, friction pile, end-bearing pile, footing
& P%)* Gr"#p %n ,)a
perimeter, plan, undrained shear strength Keywords: elevation, plan, perimeter,
T"p%$ T"p%$ A"$%a!*d %!h P%)* P%)* Gr"#p & E$%*n$ "+ P%)* Gr"#p & S*!!)*(*n! "+ P%)* Gr"#p & L"ad %!r%#!%"n A("n P%)* %n P%)* Gr"#p & *a!%5* S%n 7r%$!%"n & E8*$! "+ P%)* r%5%n %n P%)* Gr"#p
B. E$%*n$ "+ P%)* Gr"#p Gr"#p & O9*$!%5*: Appreciate
the difference between between single pile and pile group (model test test by Kezdi and Whitaker)
nderstand
approach to consider effect of pile group
& *n%!%"n
η = η
Q g (u )
∑ Qu
!roup efficiency
Q g (u ) ltimate capacity of group pile ∑ Qu "otal capacity of single pile
& S!r* %n$r*a* *)" p%)* r"#p
Keywords: single pile, pile group, stress distribution
7a$!"r A8*$!%n Gr"#p ,apa$%!/E$%*n$ & P%)* r"#p %n and ;("d*) !*!< =*>d%
Keywords: load, displacement, pile group, Kezdi, diameter, spacing, fine sand
& E$%*n$ "+ p%)* r"#p %n and =*>d%
Keywords: efficiency, width, length, model test, fine sand, row, group, pile
spacing
& E$%*n$ "+ p%)* r"#p ;("d*) !*!< ?h%!a*r #fficiency & %
#fficiency
%$Keywords: pile load, applied load, Whitaker, ultimate load of pile group, center
pile, corner pile, model test
& E$%*n$ "+ p%)* r"#p %n $)a ;*'p*r%(*n!a)< S"*r
Keywords: pile spacing, efficiency, optimum spacing, 'owers, length, model
test, clay, entonite, calculated, measured
& Pr"p"*d *$%*n$ *@#a!%"n
& ,apa$%! "+ p%)* r"#p %n $)a Step 1 *alculate capacity of single pile
Qu=Q p+Q s Step 2 *alculate ultimate capacity of group pile (taking into account efficiency of group pile) Step 3 Assuming that group pile act as a single block with dimension L g xB g xL, calculate point
bearing and shaft resistance and of the block as
Q p=A g xq g =A g cu=(L g xB g )cu N c*, and Q s= ∑ 2(L g xB g xL)∆ L Step 4 *ompare ultimate load from 'tep + and and the lower value is Q g(u).
E'a(p)* and App)%$a!%"n & E$%*n$ "+ p%)* r"#p
*onsider a group pile .f n1/0, and n2/, the pile diameter, D/011mm and pile spacing, d /211mm 3etermine the efficiency of pile group θ = tan −% (011 5 211) = +24+
(0 − %) − ( − %)0 +24+ = 1220 21 6 0 6
η = % −
& Gr"#p $apa$%! %n $)a #7ample %%%0 8et n1/0, n2/, D/19mm, d /%++1mm, L/%9m :ile has s;uare cross section and embedded in a homogenous saturated clay with cu/<1k=5m+ sing factor of safety e;ual to 0, determine the bearing capacity of group pile 'tep % *alculate bearing capacity of single pile
'tep + *alculate efficiency and group capacity (Q g(u)1) θ = tan −% (19 5 %++1) = +24+
(0 − %) − ( − %)0 +24+ = 1220 21 6 0 6
η = % −
'tep Assume single block, calculate >block? bearing capacity (Q g(u)2)
S*$!%"n O#!$"(* & A)* !" *'p)a%n !h* d%8*r*n$* %n *ha5%"r *!**n %n)* p%)* and r"#p p%)* & A)* !" "#!)%n* +a$!"r a8*$!%n $apa$%!/*$%*n$ "+ r"#p p%)* & A)* !" $a)$#)a!* *$%*n$ "+ r"#p p%)* & A)* !" $a)$#)a!* $apa$%! "+ r"#p p%)* %n and & A)* !" $a)$#)a!* $apa$%! "+ r"#p p%)* %n $)a
R*+*r*n$* & ,hap!*r 11.24 and 11.2 ;a Pr%n$%p)* "+ 7"#nda!%"n En%n**r%n<
,. S*!!)*(*n! "+ P%)* Gr"#p
T"p%$ A"$%a!*d %!h S*!!)*(*n! "+ P%)* Gr"#p & E)a!%$ *!!)*(*n! "+ %n)* p%)* ;C**rh"+ and V*%$ (*!h"d & E)a!%$ *!!)*(*n! "+ r"#p p%)* ;C**rh"+ V*%$ and B*r*>an!*5 (*!h"d< & ,"n")%da!%"n *!!)*(*n! "+ r"#p p%)*
Ba$r"#nd & L"ad d%!r%#!%"n *)" p%)* +"#nda!%"n
Keywords: pressure bulb, raft, piled raft, width, sand
& S*!!)*(*n! *)" p%)* r"#p %n and
Keywords: applied load, single pile, loaded pile, sand
& S*!!)*(*n! %n p%)* r"#p
Keywords: side of pile group, 'kempton, single pile, pile group, width
S*!!)*(*n! $a)$#)a!%"n & L"ad d%!r%#!%"n +"r *!!)*(*n! $a)$#)a!%"n "+ p%)* r"#p %n $)a
Keywords: pile group, clay, +% distribution, pile length
& L"ad d%!r%#!%"n +"r *!!)*(*n! $a)$#)a!%"n "+ p%)* r"#p %n and
Keywords: single pile, pile group, settlement, width, erezantsev, friction angle
P%)* )"ad !ran+*r (*$han%(
S*!!)*(*n! "+ %n)* p%)* & G*n*ra) *@#a!%"n
se = se (%) + se ( +) + se(,) s s
e
e
s
(%)
( +)
e
(,)
#lastic shortening of pile #lastic settlement of surrounding soil due to tip load #lastic settlement of surrounding soil due to shaft load
& E)a!%$ h"r!*n%n "+ p%)* *;1<
se(%) =
(Qwp + ξ Qws ) L A p E p
@ #lastic settlement of surrounding soil due to tip load, *;2<
se ( +) =
qwp D E s
(% −
+ µ s ) I wp
@ #lastic settlement of surrounding soil due to shaft load, *;2<
Qws D + se() = (% − µ s ) I ws pL E s
& V*%$ (*!h"d
se ( +)
se()
=
=
Qwp C p Dq p
Qws C s Lq p
S*!!)*(*n! "+ r"#p p%)* & E)a!%$ *!!)*(*n! ;V*%$ and C**rh"+<
esic e;uation
Beyerhof chart
s g ( e) =
B g D
se
& E)a!%$ *!!)*(*n! ;B*r*>an!*5<
Keywords: single pile, pile group, settlement, width, erezantsev, friction angle
& ,"n")%da!%"n *!!)*(*n!
i
( B g + i )( L g + i )
E'a(p)* and App)%$a!%"n 'oil and foundation data as given *alculate consolidation settlement !eneral e;uation for consolidation settlement
σ ! + ∆σ ! log ∆ sc = % + e" σ ! C c #
La*r " 1 2 3
S*$!%"n O#!$"(* & A)* !" $a)$#)a!* *)a!%$ *!!)*(*n! "+ %n)* p%)* #%n C**rh"+ and V*%$ (*!h"d & A)* !" $a)$#)a!* *)a!%$ *!!)*(*n! "+ r"#p p%)* #%n C**rh"+ V*%$ and B*r*>an!*5 (*!h"d & A)* !" $a)$#)a!* $"n")%da!%"n *!!)*(*n! "+ r"#p p%)*
R*+*r*n$*
. L"ad %!r%#!%"n %n P%)* Gr"#p
& L"ad %!r%#!%"n %n P)a Gr"#p
Keywords: pile group, ultimate strength, compression, tension, center or rotation
& E$$*n!r%$ L"ad%n %n P%)* Gr"#p
Keywords: assumed centre of rotation, imaginary pile, rows
& E$$*n!r%$ L"ad %n P%)* r"#p
Keywords: assumed centre of rotation, imaginary pile, rows
E. E8*$! "+ *a!%5* S%n 7r%$!%"n "n P%)*
& T" $a* "+ n*a!%5* %n +r%$!%"n
(a) *lay fill over sand (b) 'and fill over clay
(a)
(b)
& *a!%5* %n +r%$!%"n a)"n p%)* ha+! %n $)a
Keywords: fill, clay, neutral point, ground water level, lowering
& E8*$! "+ n*a!%5* %n "n p%)* %n $)a
Keywords: point bearing piles, floating piles, crushing, settlements
a. ,)a )) "5*r and C C
Qn =
C
p% γ # $ tan δ
+
. Sand )) "5*r $)a =eutral point, L1 L% =
(& − # $ ) L − # $ L
+
+
γ $ C #
+γ C$ #
− C γ γ
C Qn = ( p% Cγ $ # $ tan δ ) L% +
C
L%+ p% Cγ C tan δ
+
& Pr"!*$!%"n "+ p%)* +"r r*d#$!%"n "+ n*a!%5* %n +r%$!%"n %n $)a
Keywords: protection piles
E'a(p)* and App)%$a!%"n
R*+*r*n$*
7. E8*$! "+ P%)* r%5%n "n P%)* Gr"#p
& H*a5* $a#*d p%)* dr%5%n
Keywords: clay, surface heave
& S*!!)*(*n! $a#*d p%)* dr%5%n %n and
Keywords: settlements, cone
& S*!!)*(*n! $a#*d p%)* dr%5%n %n *'$a5a!%"n
Keywords: clay, sand, sheet pile wall, vibrations, soil anchor
