This document provides information on pile foundations, including different types of piles, classifications of piles, construction methods for piles, factors influencing pile capacity, load testing, and potential defects in cast in situ piles. It discusses deep foundations such as pile and well foundations. It classifies piles based on material, construction method, load transmission mode, cross-sectional area, size, inclination, and describes end bearing, friction, and friction-cum-end bearing piles. Construction methods for driven precast, driven cast in situ, and bored cast in situ piles are outlined.

1. PILE FOUNDATION
By –
C.M.GUPTA
Sr.Prof/Br.2
IRICEN
1

2. TYPE OF FOUNDATIONS
• SHALLOW
– SINGLE FOOTING
– COMBINED FOOTING
– RAFT
– STRIP
• DEEP
– PILE
– WELL
2

3. DEEP FOUNDATIONS
• ADEQUATE GRIP- BELOW DEEPEST
ANTICIPATED SCOUR
• DEPTH OF FOUNDATION BELOW WATER LEVEL
FOR Qf –
• NOT LESS THAN 1.33 X MAX DEPTH OF SCOUR
• SHALL NOT REST ON SLOPING ROCK STRATA
• DYNAMIC AUGMENT NEED NOT BE
CONSIDERED
3

4. CLASSIFICATION OF PILES
• BROAD CALSSIFICATION
– DRIVEN (DISPLACEMENT PILES)
– BORED (REPLACEMENT PILE)
• ON THE BASIS OF MATERIAL
– TIMBER
– STEEL
– PCC
– RCC
– PSC
– COMPOSITE
4

5. CLASSIFICATION OF PILES
• Method of construction
– Driven precast piles
– Driven cast in situ piles
– Bored precast piles
– Bored cast in situ piles
• Mode of load transmission
– End bearing piles
– Friction piles
– Friction cum end bearing piles
5

6. CLASSIFICATION OF PILES
• Sectional area
– Circular
– Square
– Tubular
– Octagonal
– H-section
• Size
– Micro (mini) piles (<150 mm)
– Small diameter pile (>150 mm < 600 mm)
– Large diameter pile (>600 mm)
6

7. CLASSIFICATION OF PILES
• INCLINATION
– VERTICAL PILES
– RAKER (BATTER PILES)
7

8. 8

9. 9

10. END BEARING PILE
10

11. FRICTION PILES
11

12. DRIVEN PILING
12

13. BORED PILING
13

14. CONSTRUCTION OF PILE FOUNDATION
• Driven precast piles
• Driven cast in situ piles
• Bored cast in situ piles
14

15. Driven precast piles
15
Drop hammer
Single/ double acting hammer
Diesel hammer
Vibratory hammer

16. Driven cast in situ Piles
– Steel casing pipe
with shoe at
bottom driven to
reqd depth
– Casting after
placing
reinforcement cage
16

17. Bored cast in situ piles
– Guide casing of 3-4 m at top of bore hole
– Bailer – chiesel
– Bentonite slurry for stabilisation
– Flushing
– Concreting after placing rein. cage
– Tremie method of concreting
– Concrete grade m 20 or higher
– High slump concrete
17

18. INSTALLATION OF BORED CAST IN
SITU PILES
• BAILER AND CHISEL METHOD
• AUGUR BORING
• BORING USING OSCILLATORS
• VIBRATORY DRILLING RIGS
18

19. BAILER AND CHISEL METHOD
19

20. AUGAR
BORING
20

21. UNDER REAMING RIG
21

22. BORED CAST IN SITU PILES
• Stabilization of bore
–Drilling Mud Circulation
(Bentonite Slurry)
Bentonite is impure clay
consisting of Montmorillonite.
Na cation responsible for
support
22

23. MUD CIRCULATION
23

24. TREMIE CONCRETING
• concrete to be rich in cement (min 370 kg/ m3),
slump – 150 -180 mm
• casing- temp/permanent
• sliding plug/steel plate flushed ahead of first
charge – to prevent mixing of water
• hopper and tremie should be closed system
• dia of tremie pipe – 200mm for 20mm aggregare
• concreting to be uninterrupted
• top of concrete in pile – above cutoff level
• min embedment in pile cap – 50 mm
24

25. TREMIE CONCRETING
25

26. TREMIE CONCRETING
26

27. Method statements for casting of piles
27

28. Method statements for casting of piles
28

29. Method statements for casting of piles
29

30. Method statements for pile cap casting
30

31. Method statements for pile cap casting
31

32. Method statements for pile cap casting
32

33. SELECTION OF TYPE OF PILES
• Availability of space and head room
• Proximity to structures
• Reliability – driven precast better
• Limitation of length- driven piles – 25 - 30 m
33

34. SOCKETTING IN ROCK
• For the end bearing piles
– Sound relatively homogenous rock including
granite and gneiss -- 1 to 2D
– Moderately weathered closely formed
including schist & slate ---- 2 to 3D
– Soft rock --- 3 to 4D
34

35. SEQUENCING OF PILING
• Normally from centre to periphery or from one
side to other
• Possibility of harm to adjacent piles be
considered. More damage in compact soils
• Order of installation should avoid creating a
compacted block of ground
• In stiff clay or compacted sand layers – from
center to outward or from one edge to across the
group
• In very soft soils – from outside to inside
35

36. SPACING OF PILES
• Determined based on the
–Type of soil
–Empirical approach
• Practical aspects of installing a pile
• Nature of load transfer
• Possible reduction in bearing capacity of a
group of piles
36

37. SPACING OF PILES
• For end bearing piles
– Governed by competency of bearing strata
– Not less than 2.5 D
• For friction piles
– Sufficiently apart to avoid overlapping zones
– Not less than 3 D
• Closure spacing possible in loose sand or fillings
for driven piles only
• Max spacing 4 D
37

38. LOAD CARRYING CAPACITY OF PILE
• In context of foundation engineering
• Load that a pile can carry without undergoing
continuous settlement for insignificant load
increments – by virtue of its boundary
conditions
• Failure of surrounding soil occurs before
failure of pile material
38

39. FACTORS INFLUENCING PILE CAPACITY
• Surrounding soil
• Installation technique
• Spacing of piles
• Symmetry of the group
• Location of pile cap
• Shape of pile cap
• Location of pile in a group
• Drainage conditions in soil
39

40. LOAD CARRYING CAPACITY OF SINGLE
PILE
• Dynamic pile formula – by using the data
obtained during piling ( conservation of energy)
– Hiley’s Formula
• More reliable for non-cohesive soils
• Not reliable for cohesive soils
• Static formula – using soil test results
• Load test – after 4 weeks of casting of pile
• Resistance due to skin friction available only
below scour line
• Drag down force
40

41. Engineering news formula
41

42. Hileys formula
42

43. LOAD CARRYING CAPACITY
• Annex B-1 of IS:2911 Part 1, Sec.2:2010 - For Granular soil
•Similar formula for clayey soil is also given in Annex B-2
43

44. 44

45. Bearing capacity factor Nγ
45

46. 46
Bearing capacity factor Nq

47. 47

48. 48

49. 49

50. 50

51. FACTOR OF SAFETY
• THE MINIMUM FOS – 2.5 FOR STATIC
FORMULA
• MINIMUM FOS – 2 FOR LOAD TEST
51

52. BEARING CAPACITY OF A PILE GROUP
• MAY BE
– EQUAL TO THE BC OF SINGLE PILE X NO. OF PILES
– LESS THAN THE ABOVE
• FRICTION PILES, CAST OR DRIVEN INTO
PROGRESSIVELY STIFFER MATERIALS & END
BEARING PILES – EQUAL
• FRICTION PILES INSTALLED IN SOFT AND CLAYEY
SOILS – LESS
• DRIVEN PILES IN LOOSE SANDY SOILS – MORE
DUE TO EFFECT OF COMPACTION
52

53. BEARING CAPACITY OF A PILE GROUP
STRATA TYPE OF PILE BC PF PILE GROUP
1. DENSE SAND NOT
UNDERLAIN BY WEAK
DEPOSITS
DRIVEN NO. OF PILES X SPC
2. LOOSE SANDY SOILS ½ (NO. OF PILES X SPC)
3. SAND NOT
UNDERLAIN BY WEAK
DEPOSITS
BORED ⅔ (NO. OF PILES X SPC)
SPC – SINGLE PILE CAPACITY
FOR PILES DRIVEN INTO SOFT OR MEDIUM CLAYS WITH 3
TO 4 D SPACING – ULTIMATE GROUP CAPACITY = ⅔ OF
THE SUM OF SINGLE PILE CAPACITY
53

54. PERMISIBLE TOLERANCE FOR PILES
• ALIGNMENT CONTROL
– VERTICAL PILES – DEVIATION OF 1.5%
– RAKER PILES – DEVIATION OF 4%
• SHIFT
– FOR PILES LESS THAN OR EQUAL TO 600 MM DIA
• NOT MORE THAN 75 MM OR D/4 WHICHEVER IS LESS
– FOR MORE THAN 600 MM. DIA. PILES
• 75 MM OR D/10 WHICHEVER IS MORE
• EXCESS DEVIATION BEYOND DESIGN LIMITS –PILE TO
BE REPLACED OR SUPPLEMENTED BY ADDITIONAL
PILES
54

55. OVERLOADING OF PILES
• 10% OF THE PILE CAPACITY MAY BE ALLOWED
ON EACH PILE
• MAX OVERLOADING ON A GROUP SHALL BE
RESTRICTED TO 40% OF THE ALLOWABLE
LOAD ON A SINGLE PILE
• SHALL NOT BE ALLOWED AT INITIAL DESIGN
STAGE
55

56. LOAD TEST
• STRESS TEST
– MAINTAINED LOAD TEST
– CONSTANT RATE OF PENETRATION TEST
– LATERAL LOAD TEST
– DYNAMIC LOAD TEST
– CYCLIC LOAD TEST
• STRAIN TEST
– LOW STRAIN INTEGRITY TEST
– HIGH STRAIN INTEGRITY TEST
56

57. PILE LOAD TESTING
(IS-2911 PART-IV)
• Initial Test
• Purpose
1. Determination of ultimate load capacity and
arrival at safe load by application of factor of
safety,
2. To provide guidelines for setting up the limits of
acceptance for routine tests,
3. To get an idea of suitability of piling system, and
4. To have a check on calculated load by dynamic
or static approaches.
57

58. PILE LOAD TESTING
(IS-2911 PART-IV)
• The number of initial tests may be selected as given below
depending upon the nature of sub-strata, number of piles and past
experience at the site.
• For small size projects (for piles less than 1 000 numbers), a
minimum of two tests.
• For large size projects (for piles more than 1 000 numbers), a
minimum of two tests for first 1 000 piles and additional one test
for every additional 1 000 piles and part thereof.
• The frequency of testing stipulated above is applicable for each
diameter of pile and rated capacity of pile in each type (mode) of
loading.
• The number of tests may be increased/decreased depending upon
whether the strata is erratic/uniform, subjected to a minimum of
two tests.
58

59. PILE LOAD TESTING
(IS-2911 PART-IV)
• Routine Test
– On ½ percent of piles, can be increased to
2% depending on strata
• Purpose
1. Checking the safe load as determined from static
analysis
2. Detection of any unusual performance contrary
to the findings of the initial test, if already done;
and
3. Workmanship.
59

60. PILE LOAD TESTING
(IS-2911 PART-IV)
• Routine Test
•The piles to be tested for routine tests may preferably be selected on
the basis of the following:
a. Abnormal variation in concrete consumption.
b. Sudden drop in concrete level during construction of piles.
c. Problems encountered during boring and tremie operation.
d. Significant variation in depth of pile with respect to other
adjoining piles and boring record.
e. Anomalies observed during the driving operation in case of driven
piles.
f. Piles under sensitive locations of structures.
g. Any doubt arising from non destructive test results.
60

61. PILE LOAD TESTING
(IS-2911 PART-IV)
• VERTICAL LOAD TEST
–Maintained load method
–Cyclic load test (To separate skin friction and end bearing)
–CRP test (Uniform penetration)
• LATERAL LOAD TEST
• PULL OUT TEST
61

62. LOAD TEST-INITIAL TEST
• The safe load on a single pile will be least of the
following
For piles dia upto 600 mm
– Two third of the final load at which total displacement
attains a value of 12 mm
– 50 % of the final load at which the total displacement
equals 10 % of the dia. of pile and 7.5% of bulb dia in
case of under reamed piles
For piles dia more than 600 mm
– Two third of the final load at which total displacement
attains a value of 18 mm or 2% of dia whoever is less
– 50 % of the final load at which the total displacement
equals 10 % of the dia. of pile and 7.5% of bulb dia in
case of under reamed piles
62

63. LOAD TEST - INITIAL
• THE SAFE LOAD FOR GROUP OF PILES
– FINAL LOAD AT WHICH TOTAL
DISPLACEMENT IS 25 MM
– TWO THIRD OF FINAL LOAD AT WHICH
DISPLACEMENT IS 40 MM
63

64. LOAD SETTLEMENT CURVE
SAFE LOAD
Least of 2/3
P1 or ½ P2
FOR GROUP
Least of Load
corrp. to 25 mm
sett or 2/3
corrp. to 40 mm
sett.
LOAD IN
INCREMENTS
OF 20%
Final load
maintained for
24h
64

65. LOAD TEST – ROUTINE TEST
• Test load will be atleast 1.5 times the
working load
• Max. settlement should not > 12 mm
for piles dia upto 600 mm
• 18 mm or 2 percent of pile diameter whichever
is less for piles of diameter more than 600 mm.
• for group of piles max. Settlement
should not > 25 mm
65

66. STATIC LOAD TEST
66

67. PILE LOAD TEST
(KENTELEDGE ARRANGEMENT)
67

68. PILE LOAD TEST
(WITH ANCHOR PILES)
68

69. DYNAMIC PILE TESTING
• SUPPLEMENTS STATIC TESTING
• HIGH STRAIN TESTING
– PROVIDES DATA ON FORCE & ACCELERATION OF PILE
– EVALUATION OF BEARING CAPACITY
– FACILITATE IMMEDIATE DECISION ABOUT ACCEPTANCE
OR REJECTION OF PILE
• LOW STRAIN TESTING
– FOR TESTING CONTINUITY OF PILE
– INFORMATION ABOUT DIMENSIONS AND
CONSISTANCY OF MATERIAL
ASTM D 4945
69

70. DYNAMIC PILE TESTING as per ASTM D 4945
70

71. DYNAMIC PILE TESTING
71

72. DEFECTS IN CAST IN SITU PILES
• HONEY COMBING DUE TO INADEQUATE
VIBRATIONS
• SEGREGATION DUE TO IMPROPER CONCRETE
PLACEMENT METHODS
• WASHOUT OF CEMENT DUE TO GROUNDWATER
FLOW
• CRACKS IN PILE SHAFT DUE TO SHRINKAGE
• INCLUSION OF FOREIGN MATERIAL
• NECKING DUE TO COLLAPSE OF SIDE WALLS
DURING WITHDRAWAL OF TEMPORARY CASING
72

73. NECKING IN PILE
73

74. NECKING IN PILE
74

75. 75