Pile Load Test
What is it? Why? How is it done? How many piles? Which piles? When to conduct the test? What is the maximum test load? How to interpret test results?
Which test method should we adopt?
Pile Testing
Static Load Test - Test Setup
Reaction Beam Load Cell Stiffeners Plate Spherical Bearing
Ram
Hydraulic Jack Bourdon Gage Dial Gage
LVDT Mirror
Bracket Attached to Pile Wire Scale Test Pile Grade
Kentledge Reaction System
Pile Testing
Anchored Piles Reaction System
Methods of Static Load Test
Pile Testing
Pile Testing
Results of a Maintained Load Test
Osterberg Load Test Concept
Conventional Q Osterberg Cell
Qs
Qs Qo
Expanding O-Cell
Qt
Qo Qt
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Pile Testing
The Osterberg Cell
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Bored Pile
Dimaeter = 3 m Length =67m
Max. Load = 279,000 kN 27,900 t
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Pile Testing
The Osterberg Cell
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Pile Testing
The Osterberg Cell
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Pile Dynamic Analyzer (PDA Tests)
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Pile Testing
Pile Dynamic Analyzer (PDA Tests)
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Statnamic Load Test Setup
Concrete or Steel Reaction Mass
Pressure Chamber Load Cell Base Plate Grouted to Foundation
Loose Granular Fill Propellant Launching Cylinder Piston Base Displacement Measuring Means
Pile or Drilled Shaft
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Pile Testing
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Pile Testing
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Comparison of Test Duration
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Pile Testing
Comparisons between Static, Statnamic and Dynamic Pile Load Tests
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When should the pile load test be conducted?
Clay Pile Type
Sand Driven Piles & Bored Piles
Rock
Method of Testing
PDA, Statnamic, O-Cell, Static
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Pile Testing
Field Data on Friction Pile Capacity in Clay
(after Vesic, 1977)
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Number of piles to be tested?
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Pile Testing
BCA/IES/ACES Advisory Note 1/03
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What is the maximum test load?
Working Load Test Qmax = 2 QALL Qmax = 2.5 or 3 QALL
QULT Q
Preliminary or Ultimate Load Test
QALL 2QALL 3QALL
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Pile Testing
Interpretation of Failure Load
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Forms of Load-Settlement Curves
(Tomlinson, 1987)
Friction pile in soft clay
Friction pile in stiff clay
Pile end bearing on weak porous rock
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Pile Testing
Forms of Load-Settlement Curves
(Tomlinson, 1987)
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Proper Scaling of Load-Displacement Diagram
What are the failure loads of these two tests?
Proper Scaling
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Pile Testing
Determination of Qult
(after De Beer, 1967)
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Determination of Qult
(after Mazurkiewics, 1974)
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Pile Testing
Determination of Qult
(after Van Der Veen, 1953)
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Brinch Hansens 90% Criterion
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Pile Testing
Brinch Hansens 80% Criterion
Qu 0.8Qu
0.25 u
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Hirany & Kulhawys Method for Bored Piles
(Hirany and Kulhawy, 1989)
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Pile Testing
Hirany & Kulhawys Method for Bored Piles
(Hirany and Kulhawy, 1989)
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Tangent Intersect Method
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Pile Testing
Tangent Intersect Method (Fuller & Hay, 1970; Butter & Hay, 1977)
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Davissons Method (1973)
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Pile Testing
10% Rule
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Qu
Chins Method
(Chin, 1970)
m = 1/Qu
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Pile Testing
Pile Load Test
(after Chin, 1970)
Qs = 1 / a1 Qs + Qp = 1 / a2 = Qult
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Ultimate Skin Friction and End Bearing by Chins Method
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Pile Testing
Comparison of Interpretation Methods
(Sharma et al, 1984)
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Chins Stability Plot
(after Chin, 1985)
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Pile Testing
Chins Stability Plot (after Chin, 1985)
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Chins Stability Plot
(after Chin, 1985)
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Pile Testing
Chins Stability Plot
(after Chin, 1985)
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Pile Instrumentation
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Pile Testing
Static Load Test on Pile with Telltales
Q1+Q2+Q3, etc. Q1+Q2+Q3 Q1+Q2 Q1 Load (Q)
Telltale B Telltale A Telltale A
Movement
Pile Head
Telltale B
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Load Test of Bored Pile in Old Alluvium
(Chin et al, 1985)
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Pile Testing
Load Test of Bored Pile in Old Alluvium
(Chin et al, 1985)
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Load Test of Bored Pile in Jurong Formation
(Chang & Goh, 1988)
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Pile Testing
Load Test of Bored Pile in Old Alluvium (Chin et al, 1985)
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Load Test of Bored Pile in Old Alluvium (Chin et al, 1985)
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Pile Testing
Load Test of Bored Pile in Reclaimed Land
(Wong et al, 1996)
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Load Test of Bored Pile in Reclaimed Land
(Wong et al, 1996)
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Pile Testing
Residual Stresses in Driven Piles
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Correction for Residual Stress in Driven Piles
(Altaee et al, 1992)
(-ve)
(+ve)
(+ve)
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Pile Testing
Correction for Residual Stress in Driven Piles
(Fellenius, 1989; Altaee et al, 1992)
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Correction for Residual Stress in Driven Piles
(Fellenius, 1989; Altaee et al, 1992)
Before correction
After correction
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Pile Testing
