Apresentao do PowerPoint

1
The Sixth International Conference on the
APPLICATION OF STRESS-WAVE THEORY TO PILES
Quality Assurance on Land and Offshore Piling
September 11, 12 and 13, 2000
São Paulo, BRAZIL
2
INTRODUCTION
3
Please select region that is your main business
market

• 1 Africa
• 2 Asia
• 3 Australia and Oceania
• 4 Central and North America
• 5 Europe
• 6 South America
• 7 Worldwide

4
Please select your main activity

• 1 Academic (professors and students)
• 2 Contractor
• 3 Foundation Designer and Consultant
• 4 Government Agency
• 5 Owner of foundation jobs
• 6 Testing Consultant Company
• 7 Equipment manufacturer
• 8 Nome of the above options

5
How long have you been working with Stress Wave
Theory?

• 1 less than 1 year
• 2 1 to 5 years
• 3 5 to 10 years
• 4 10 to 20 years
• 5 more than 20 years
• 6 I never used it

6
According to your own experience, what kinds of
piles are most commonly tested?

• 1 auger cast
• 2 Franki type
• 3 precast concrete
• 4 drilled
• 5 open ended steel pipe
• 6 steel (other)
• 7 wooden

7
Wave Mechanics and its Applications to Pile
Analysis
SESSION 1
8
Which is the field investigation more frequently
used in your country to estimate the static
capacity for driviability prediction?

• 1 SPT or SPT-T
• 2 CPT or CPTU
• 3 Pressiometer or Dilatometer
• 4 other

9
Which is the usual method for pile installation
predictions and field control in your country?

• 1 Wave Equation Analysis
• 2 Dynamic Formula
• 3 Simplified Methods from Wave E. Theory
• 4 Calibrated Dynamic Form. based on W.E.Theory
• 5 Other

10
Do you think that the Smith soil model represents
reasonably well the soil behaviour during dynamic
loading?

• 1 Yes
• 2 No
• 3 Only for some soils
• 4 I do not know

11
Do you use more sophisticated soil models for
pile installation predictions and signal match?

• 1 Yes
• 2 No

12
Do you normaly perform wave equation analysis
considering the Residual Stress Effect?

• 1 Yes
• 2 No

13
For a given time after pile installation, what is
the applied energy concept to evaluate the static
bearing capacity?

• 1 One blow with constant energy
• 2 Multiple blows with constant energy
• 3 Multiple blows with increasing energy
• 4 none of the above

14
How many dynamic tests with different time after
installation are necessary to evaluate the set-up
effects?

• 1 Only one
• 2 From 1 to 3 tests
• 3 From 3 to 5 tests
• 4 more

15
In your opinion Quake and Damping are soil
parameters?

• 1 Yes
• 2 No

16
If you have the possibility to measure only one
variable during dynamic test, which would be your
choise?

• 1 Force with time
• 2 Acceleration with time
• 3 Displacement with time

17
Driving Equipment and Recent Developments -New
Technologies for Quality Assurance of Piles
SESSION 2
18
Which hammer technology have you mostly analyzed,
monitored, operated and/or studied?

• 1 diesel
• 2 free-fall
• 3 hydraulic
• 4 steam or air compressed
• 5 vibratory
• 6 none of the above options

19
What is the most important hammer quality for a
pile driving contractor?

• 1 adjustability
• 2 kinetic energy
• 3 momentum
• 4 potential energy
• 5 ram weight
• 6 reliability
• 7 transferred energy
• 8 none of the above options

20
What is the most important hammer quality for a
dynamic load tester?

• 1 adjustability
• 2 kinetic energy
• 3 momentum
• 4 potential energy
• 5 ram weight
• 6 reliability
• 7 transferred energy
• 8 none of the above options

21
How frequently do you BELIEVE the hammer cushion
replacement should take place (EXCEPT HYDRAULIC
HAMMERS)?

• 1 of course it depends of the cushion type, but
  before it reaches 5000 blows is wise
• 2 of course it depends of the cushion type, but
  between 5000 and 10000 blows is wise
• 3 of course it depends of the cushion type, but
  between 10000 and 20000 blows is wise
• 4 I have it changed only when it burns or when I
  hear a metallic impact sound
• 5 I never think about it

22
Have you ever designed or specified a hammer
cushion?

• yes, I always do it
• no, I always use the hammer
• manufacturers recommendation
• yes, but just when it is really
• necessary
• 4 I never think about it

23
What is the most important property of a pile
cushion (packing on top of concrete piles)?

• 1 ability to adjust to pile surface
• 2 ability to easily replace
• 3 high coefficient of restitution
• 4 softness
• 5 none of the above options

24
Pile integrity and low strain dynamic testing
SESSION 3
25
Please select the appropriate name for integrity
by low strain dynamic testing

• 1 Integrity by low strain dynamic testing
• 2 Low strain pile integrity testing
• 3 Sonic integrity testing (SIT)
• 4 Pile integrity testing (PIT)
• 5 Integrity by impact echo measurement
• 6 Integrity by pulse echo measurement
• 7 Integrity by acoustic wave analysis
• 8 Integrity by low strain wave analysis
• 9 None of the above

26
Please select THREE of the following that you
consider most vital for wider use and acceptance
of pile integrity by low strain dynamic testing
technique

• Standardization of testing
• interpretation procedure
• Further research on piles and models
• with known defects
• Use of the latest in acquisition and
• processing of dynamic signal
• Research to quantify the reliability of
• and the risk from predicted defect
• Predefined clear strategy for remedial
• action when defects are predicted
• Research on analytical processing and
• display of vital information
• Continuing education and awareness
• efforts aimed at practicing engineers
• Further research on testing on piles with
• footings in existing structures
• 9 There are other aspects more important

27
Pile-Soil Interaction
SESSION 4
28
Statement Today almost all affects concerning
the pile soil interaction are described and
understood!

• 1 I agree
• 2 I disagree

29
Statement Today most of the questions related
to the comparison of static and dynamic load test
results are answered!

• 1 I agree
• 2 I disagree

30
How are static load tests in your home country
performed and then compared with dynamic load
tests?

• 1 Constant rate of penetration test
• 2 Long term maintained load test
• 3 Stepped load increment test
• 4 Cyclic loading test
• 5 Combination of the above

31
What minimum time do you consider necessary
between a dynamic and a static load test at a
pile embedded in silt/clay?

• 1 gt 1 day
• 2 gt 2 days
• 3 gt 1 week
• 4 gt 2 weeks
• 5 gt 4 weeks

32
Do contractors and/or officials from your
experience generally demand the evaluation of
dynamic load test results by static load tests?

• 1 no, normally not
• 2 yes, sometimes in critical cases
• 3 yes, frequently
• 4 yes, always

33
Statement Today most of the questions related
to set-up effects of piles are answered!

• 1 I agree
• 2 I disagree

34
From your experience Up to what percentage can a
driven pile embedded in silt/clay gain shaft
resistance four weeks after the end of initial
driving?

• 1 100 - 125
• 2 125 - 150
• 3 150 - 175
• 4 over 175

35
What period of time between two tests would you
recommend, if you want to test for set up effects
in sand?

• 1 gt 1 hour
• 2 gt 1 day
• 3 gt 1 week
• 4 gt 2 weeks
• 5 gt 4 weeks

36
Do you take advantage of finite element analysis
of the pile-soil interaction in your daily
practice?

• 1 no, usually not
• 2 yes, sometimes
• 3 yes, frequently

37
Do you use finite element analysis for the
evaluation of _____ pile properties?

• 1 dynamic
• 2 static

38
Statement Today almost all affects concerning
the pile soil interaction are described and
understood!

• 1 I agree
• 2 I disagree

39
Statement Today most of the questions related
to the comparison of static and dynamic load test
results are answered!

• 1 I agree
• 2 I disagree

40
Codes
SESSION 5
41
Are you familiar with concepts of limit states
design?

• 1 Yes
• 2 Have heard of it.
• 3 No

42
Do you think that limit states design leads to
more rational and more economical design ?

• 1 Yes
• 2 No
• 3 Do not know

43
Are you familiar with ISO 2394 "General
principles on reliability for structures"?

• 1 Yes.
• 2 Have heard of it.
• 3 No.

44
Which do you prefer, material factor approach or
resistance factor approach for pile foundation
design?

• 1 Material factor approach
• 2 Resistance factor approach
• 3 Depends

45
My rating for Signal matching is

• 1 excellent
• 2 fair
• Bad
• Dont know the method

46
My rating for Case method is

• 1 excellent
• 2 fair
• Bad
• Dont know the method

47
High strain dynamic testing of Driven and
Cast-in-Site Large Piles - Dynamic testing of
Large Piles
SESSION 6
48
For those performing high strain dynamic pile
testing, what piles do you dynamically test?

• 1 Only driven piles (concrete or steel)
• Only drilled Shafts, bored piles, CFA
• piles or other non-driven cast-in-situ piles
• 3 More driven piles than non-driven piles
• 4 More Non-driven than driven piles

49
What global or total safety factor should be used
for high strain dynamic testing and signal
matching (e.g. CAPWAP) of non-driven piles like
drilled shafts, bored piles or CFA piles?

• 1 less than 2.0
• 2 2.0
• 3 2.25
• 4 2.5
• 5 greater than 2.5

50
What is main consideration in planning for
dynamic testing of large piles? (max. 2 options)

• 1 Obtaining appropriate sized hammer
• 2 Acceptability of test results by client
• 3 Pile top preparation
• 4 Cost savings or time savings
• Prove higher loads or reduce safety
• factor for economic benefit

51
If dynamic test result is lower than desired
ultimate capacity, but permanent set is less than
1 mm per blow, you would...

• Require more energy input to
• prove desired ultimate load
• Consider dynamic result as acceptable
• "proof test", if safety factor is at least 1.5
• Use safety factor of 2.0 to compute a
• reduced design load
• 4 Reject dynamic test result

52
What aspect of dynamic testing of large diameter
piles needs the most additional research? (max. 2
options)

• 1 Shaft soil model
• 2 Toe soil model
• 3 Pile Model for non-uniform shafts
• 4 How to select hammer
• How to analyze a sequence of
• blows with variable drop heights

53
Signal matching (e.g. CAPWAP) of dynamic pile
test results provides resistance distribution
information for high capacity piles. Which use
is LEAST important to you?

• 1 Helps optimize pile lengths
• 2 Uplift capacity
• 3 Compression capacity
• Evaluates soils for negative
• friction (downdrag) potential
• Superposition of driving and
• restrike results at refusal

54
What capacity evaluation method for static load
tests is preferred for large diameter end bearing
piles?

• Methods relating to diameter
• (e.g. load at settlement of D/10)
• Methods for some fixed settlement
• (e.g. load at settlement of 20 mm)
• Methods relating to pile stiffness
• (e.g. Davisson procedure)
• Methods evaluating shape of curve
• (e.g. tangents)
• 5 Judgment

55
SPT Measurements and Special Field Monitoring
Tests
SESSION 7
56
Did you have any experiences of measuring the
driving efficiency of SPT at actual sites?

• 1 None
• 2 1-2 times
• 3 over 3 times

57
If you select b or c in question 2, which
region does your country belong to?.

• 1 North America
• 2 South America
• 3 North Europe
• 4 South Europe
• 5 Asia
• 6 Middle East
• 7 Africa
• 8 Oceania
• 9 Others

58
Is it necessary to measure the driving energy or
work done, for accuracy of SPT N value in every
test? Or, Is it sufficient in practice to use a
constant driving efficiency for each SPT?

• 1 Necessary to measure
• 2 Use a constant driving efficiency
• 3 Others

59
What kind of test do you think is preferable for
pile foundation design, SPT or CPT?

• 1 SPT
• 2 CPT
• 3 Combination SPT and CPT
• 4 Others

60
Is there any possibility of determining some soil
parameter or strength from SPT?

• 1 I think so
• It is difficult. It needs to
• change SPT method itself.
• If some other testing, such as
• shear velocity measurement, is
• combined, it may be possible.
• 4 Others

61
Which is better for obtaining the soil
parameters, the development of a new testing
method combining SPT with CPT, such as percussion
drilling, or the modification of the current SPT?

• 1 New Method
• 2 Modification of SPT (including interpretation)
• 3 Others

62
Vibration Pile DrivingVibration in Pile Driving
SESSION 8
63
Does the statement below describe an aspect of
your professional practice and local experience
? Variable frequency vibratory hammers are
commonly used to install sheet piles

• 1 Yes
• 2 No

64
Does the statement below describe an aspect of
your professional practice and local experience ?
Fixed frequency vibratory hammers are commonly
used to install sheet piles

• 1 Yes
• 2 No

65
Does the statement below describe an aspect of
your professional practice and local experience
?Pre-construction surveys of existing structures
to document pre-existing damage are often
performed
1 Yes 2 No
66
Does the statement below describe an aspect of
your professional practice and local experience
?Predictions of ground vibrations are made as a
part of the design studies

• 1 Yes
• 2 No

67
Does the statement below describe an aspect of
your professional practice and local experience
?Ground vibrations are often monitored when
vibration-induced problems for nearby facilities
are a project concern

• 1 Yes
• 2 No

68
Does the statement below describe an aspect of
your professional practice and local experience
?Measurements of vibratory hammer-pile
performance (e.g. force and acceleration
measurements) are becoming a part of our practice

• 1 Yes
• 2 No

69
Ground vibrations can have the following
consequences

• Soil slope instability
• Damage to structures
• Disturbance to people
• Damage to buried pipes
• Instability of retaining walls

70
The levels of tolerable vibrations are
established by (max 3 options)

• 1 National building code
• 2 Regional or local building code
• 3 Published empirical correlations
• 4 Synthesis of local experience

71
What three factor(s) most influence the
determination of threshold levels of ground
vibrations causing problems?

• 1 Types of nearby structure/foundation
• 2 uses of nearby facilities
• 3 Site-specific geology
• 4 Groundwater level
• 5 Type of pile driving equipment
• 6 Type of pile
• 7 Distance from the pile driving activity

72
At what distance from your sensitive nearby
structures should you become concerned about
vibrations from impact-driven piles?

• 1 60 m
• 2 30 m
• 3 15 m
• 4 10 m
• 5 5 m
• 6 Closer

73
When pile driving in a city environment, in loose
to medium granular soils, what hammer type is
most preferable?

• Low frequency vibrodriver
• High frequency non-resonant vibrodriver
• Air hammer
• Heavy hydraulic hammer
• Pre-augering

74
Which method of installation of a closed end pipe
pile to a given depth into medium dense sand will
provide the highest long-term bearing capacity ?

• Impact driving
• Vibratory driving
• Jacking
• No difference

75
Statnamic and Other Similar Tecniques
SESSION 9
76
How is your intuitive feeling on the accuracy of
rapid load testing compared to static load
testing (SLT)?

• 1 Almost equivalent to SLT
• 2 Within 10 error of SLT
• 3 Within 20 error of SLT
• 4 Poor
• 5 Variable

77
Case Histories, Pile Setup and Correlations
Between Test MethodsPrediction Reliability
SESSION 10
78
If you could choose only one set of test results
from a given site to predict static performance
(load x displacement curve to failure) of driven
piles, which one would you choose for design
purposes?

• 1 SPT
• 2 triaxial tests of samples taken at several
  depths
• 3 dilatometer
• 4 cone
• 5 pressuremeter
• 6 other

79
If you could choose only one set of test results
from a given site to predict static performance
(load x displacement curve to failure) of
cast-in-place piles, which one would you choose
for design purposes?

• 1 SPT
• 2 triaxial tests of samples taken at several
  depths
• 3 dilatometer
• 4 cone
• 5 pressuremeter
• 6 other

80
Consider the ratio A Qd/Qs, where Q represents
ultimate bearing capacity and subscripts d and s
refer to dynamic and static load tests. On
average you would expect

• 1 A gt 1.3
• 2 1.3 gt A gt 1.1
• 3 1.1 gt A gt 0.9
• 4 0.9 gt A gt 0.7
• 5 0.7 gt A

81
Consider the ratio C Sd/Ss, where S represents
displacement at working load and subscripts d and
s refer to dynamic and static load tests. On
average you would expect

• 1 C gt 1.3
• 2 1.3 gt C gt 1.1
• 3 1.1 gt C gt 0.9
• 4 0.9 gt C gt 0.7
• 5 0.7 gt C

82
Quality assurance of driven piles is most
efficiently achieved by means of

• just pile construction records
• (set elastic rebound)
• static load tests pile
• construction records
• dynamic load tests pile
• construction records
• statnamic load tests pile
• construction records
• static load tests dynamic or statnamic
• tests pile construction records
• 6 other

83
Quality assurance of cast-in-place piles is most
efficiently achieved by means of

• just pile construction records (penetration
• torque, injection pressures and volumes)
• static load tests pile construction
• records
• dynamic load tests pile construction
• records
• statnamic load tests pile construction
• records
• static load tests dynamic or statnamic
• load tests pile construction records
• 6 other

84
Consider N to be the number of piles in a
specific job and n the number of tests required
for quality assurance. The ratio n/N should be
specified in codes as

• 1 a fixed ratio
• a variable ratio, dependent
• on pile type
• a variable ratio, dependent on
• pile type and working load
• a variable ratio, dependent on pile type,
• working load, and size of pile groups
• a variable ratio, dependent on pile type,
• working load, size of pile groups, and N

85
Confidence of Pile Integrity Testing
Workshop 1
86
In what region of the world do you exert most of
your professional activities?

• 1 South and Central America
• 2 North America
• 3 Europe
• Middle East
• Far East
• 6 Australia and New Zealand
• 7 Africa

87
What is your or your companys main activity?
(Multiple choices allowed)

• Foundation design and Geotechnical consulting
• Specialist testing company
• 3 Foundation contractor
• 4 Main contractor
• 5 University (professor, student)
• 6 Hammer manufacturer
• 7 Other

88
What kind of dynamic testing is older in your
region?

• 1 Dynamic Load Testing
• 2 Low strain (sonic) integrity testing
• 3 Both started at about the same time

89
What kind of integrity testing is more popular in
your region?

• Low strain (sonic) integrity
• testing (PIT or SIT)
• Cross-hole Sonic Logging
• (CSL)
• Core drilling
• Other
• None (no integrity testing is
• usually done in my region)

90
What do you think of the results of low strain
(sonic) integrity testing?

• 1 Always reliable
• 2 Most of the times reliable
• 3 Sometimes reliable
• 4 Never reliable

91
What do you think of the results of Cross-hole
Sonic Logging (CSL)?

• 1 Always reliable
• 2 Most of the times reliable
• 3 Sometimes reliable
• 4 Never reliable

92
Is the Transient Response Method used in your
region?

• 1 Always
• 2 Sometimes
• 3 Never
• I dont know what the Transient Response
• Method is

93
Is Frequency Domain Analysis used in your region?

• 1 Always
• 2 Sometimes
• 3 Never
• 4 I dont know what Frequency Domain Analysis is

94
What integrity test method you think is more
reliable?

• 1 Low strain (sonic) integrity testing (PIT or
  SIT)
• 2 Cross-hole Sonic Logging
• 3 Both are equally reliable
• 4 Both are totally unreliable
• 5 Depends on the job

95
Quality in Dynamic Testing
Workshop 2
96
From whom did you receive training in your field
of testing?

• 1 The manufacturer of the testing equipment
• 2 An agent of the equipment manufacturer
• A member of my company who had
• received training from the manufacturer
• A member of my company who had
• received similar internal training
• I received no formal training
• Not applicable

97
When I am uncertain about data I have collected
or analyzed, I generally .

• 1 Cover up the problem
• 2 Solve the problem myself
• 3 Report the uncertainty to my client
• 4 Seek assistance from a senior colleague
• Seek assistance from the manufacturer or his
  agent
• Not applicable

98
When I am testing in the field, I generally .

• Give the client as much advice
• as he requests
• Give the client as much advice
• as I can
• Give the client some preliminary
• written advice
• Give the client some preliminary
• verbal advice
• Never give any advice on the pile
• capacity or condition
• Not applicable

99
My pile testing involves

• Assessments of pile compression
• capacity only
• Assessments of pile compression
• and tension capacity
• Assessment of pile damage and/or
• capacity
• All the above PLUS hammer
• performance
• All the above PLUS providing advice
• on driving criteria
• Not applicable

100
I believe that pile testing should be conducted
by persons with at least the following
qualification

• 1 A specialist geotechnical engineer
• 2 A civil engineer
• 3 An engineer (other branch)
• A university graduate with a Science
• degree
• A technician
• No opinion

101
The term quality assurance means to me

• A system which requires reporting of
• any outcome or process which is not
• in compliance with the specification
• A system where there is a checking
• superintendent
• Having experienced personnel
• performing the construction
• Having experienced personnel
• performing the testing
• 5 Lots of paperwork

102
My clients

• Have no knowledge of pile
• design or testing
• Have no knowledge about
• pile testing
• Understand only the broad basis
• of pile testing
• Have a good understanding of
• pile testing
• Are able to independently
• evaluate my results
• Not applicable

103
On most projects, the testing services I provide
are

• The only method of foundation
• verification used
• The primary method of foundation
• verification used
• A secondary method of foundation
• verification used
• Used only as a back-up
• 5 Question does not apply

104
On most projects, the number of piles tested is
about

• 1 1 or less
• 2 2 to 5
• 3 6 to 15
• 4 16 to 25
• greater than 30
• Not applicable

105
Comment on this statement.I feel I need more
training to increase my testing knowledge

• 1 Strongly agree
• 2 Agree
• 3 Partly agree
• 4 Disagree
• Strongly disagree
• Not applicable

106
Comment on this statement. I believe
there is a need for a comprehensive textbook or
guide to be written in my field of pile testing

• 1 Strongly agree
• 2 Agree
• 3 Partly agree
• 4 Disagree
• Strongly disagree

107
Comment on this statement. Given that pile
testing is a central element of foundation
quality assurance, pile testers should be subject
to a quality assurance process.

• 1 Strongly agree
• 2 Agree
• 3 Partly agree
• 4 Disagree
• 5 Strongly disagree