advances in foundation testing equipment and the potential...
TRANSCRIPT
©Strainstall 2016
Advances in Foundation Testing equipment and the
potential for dynamic testing of cast in place foundations
using the SIMBAT method in Singapore
©Strainstall 2016
Session One
Current practices used for the assessment of
new foundations and existing foundations
• Low Strain Frequency response & Impedance Profiling
• Parallel Seismic
• Downhole Magnetometer
• Sonic Logging Tomography
• Thermal integrity profiling
• Rate of Corrosion
Huw Williams - Product Manager Foundation Testing
©Strainstall 2016
Session TWO
The SIMBAT method for assessment of pile
performance dynamically.
• SIMBAT testing methodology and practical
considerations
• Comparison with other dynamic and RLT methods
• Relevant case histories
• The potential for SIMBAT in Singapore
Iwan Jones – Technical Authority Foundation Testing
©Strainstall 2016
Who we are: James Fisher History
©Strainstall 2016
Who we are: JF subsidiaries
©Strainstall 2016
Who we are: JF Global Locations
©Strainstall 2016
Materials Testing
What we do: Expertise
Structural Investigation
Test Equipment Pavement Analysis
SMART Asset
Management
Proof Testing
©Strainstall 2016
What we do: Expertise
Foundation Testing
Bi-Directional LT
Rate of Corrosion
Static Load testing
Low Strain testing Sonic Logging
SIMBAT Dynamic testing
©Strainstall 2016
Auger stays
behind casing
Casing is taken
past weak soil
layers
What Causes Defects?
©Strainstall 2016
`
Concrete slumps
into void leaving
neck
Short casing… Bore partially
collapses
Casing is
extracted
and….
or Auger advances
deeper than casing
What Causes Defects?
©Strainstall 2016
Pile cased through
running water
Pile washed out when
casing extracted
What Causes Defects?
©Strainstall 2016
Pile is cased though
weak ground
Drilled through
bentonite or water
Tremie is placed
Pile is concreted
If tremie lifts out of
concrete…
A band of contaminated
concrete can be left
What Causes Defects?
©Strainstall 2016
Pile Cracked in top few
metres in weak soil The good news is… its
easy to detect with PIT
What Causes Defects?
©Strainstall 2016
Session One: Low Strain Frequency Response
©Strainstall 2016
Session One: Low Strain Frequency Response
TDR2 Pile Integrity Tester
©Strainstall 2016
Session One: Low Strain Time Domain
TECOLITE Pile Integrity Tester
©Strainstall 2016
Session One: Low Strain Frequency Response
Time Domain Test
Pile Head Velocity v Time Force Applied v Time
©Strainstall 2016
Fourier Transform
Convert to Freq Velocity / Force
Force
Velocity
Mobility
Session One: Low Strain Frequency Response
©Strainstall 2016
Time
Time domain
L = c t / 2
Frequency
Frequency domain
∆F ½∆F
L = c / 2 ∆F
t
Fixed End
Time t
L = c t / 2
Time domain
Frequency
∆F ∆F
L = c / 2 ∆F
Frequency domain
Free End
©Strainstall 2016
Length = c/2∆f
Stiffness = 2π f(m)
V/F(m)
Mobility = 1/ρcA
Frequency
V
F
Session One: Low Strain Frequency Response
Frequency Response (Mobility) Curve
©Strainstall 2016
Mobility = 1/ρcA
Frequency
V
F c = 3500m/sec
ρ = 2300Kg/m3
c = 4000m/sec
ρ = 2400Kg/m3
Session One: Low Strain Frequency Response
Frequency Response (Mobility) Curve
©Strainstall 2016
Frequency
V
F
Frequency Response (Mobility) Curve
Reduced section or concrete quality
Session One: Low Strain Frequency Response
Frequency Response (Mobility) Curve
Mobility = 1/ρcA
©Strainstall 2016
Mobility = 1/ρcA
Frequency
V
F
Increased section or concrete quality
Session One: Low Strain Frequency Response
Frequency Response (Mobility) Curve
©Strainstall 2016
Frequency Hz
1/ρcA
V
F
Session One: Low Strain Frequency Response
Short Pile – Weak Soil
©Strainstall 2016
Frequency Hz
1/ρcA
V
F
Session One: Low Strain Frequency Response
Long Pile - Stiff Soil
©Strainstall 2016
influenced heavily by pile head
diameter and upper soils
Stiffness is best used
comparatively for each site
Pile Diameter (m)
Sti
ffn
ess (
MN
/mm
)
0.5 1.0 1.5
1
2
3
4
5
As guide should be approx
2 x diameter (m)
Session One: Low Strain Frequency Response
Dynamic Pile Head Stiffness – MN/mm
©Strainstall 2016
Session One: Low Strain Frequency Response
Simulation and Impedance Profiling
©Strainstall 2016
Software
Demonstration
©Strainstall 2016
Case History
Session One: Low Strain Frequency Response
• Frequency Response Testing
• Tower leg Foundations
• New Zealand
• Line Refurb
• Additional Load
• Wind Loading
©Strainstall 2016
Case History
Session One: Low Strain Frequency Response
High winds caused extensive
Power Infrastructure damage
©Strainstall 2016
Case History
Session One: Low Strain Frequency Response
Foundations were torn out
of the ground
©Strainstall 2016
Case History
Session One: Low Strain Frequency Response
Foundations were not as
Expected to be !!
©Strainstall 2016
Case History
Session One: Low Strain Frequency Response
All Pre-1960 tower foundations
were tested using frequency
response method
©Strainstall 2016
Session One: Low Strain Frequency Response
Case History : Accuracy of Depth Measurement
Length measurements were
generally within 5% accuracy
Assumed wave-speed velocity on
older piles found to be approx
3500m/sec
©Strainstall 2016
Session One: Low Strain Frequency Response
Case History : Impedance Profile
Impedance profiling used to check
presence of under-reaming – or not
- on all foundations
©Strainstall 2016
Session One: Low Strain Frequency Response
Case History : Now specified and used worldwide by power companies
Costa Rica Saudi Arabia Hungary
New Zealand United Kingdom Russia
©Strainstall 2016
Session One: Low Strain Frequency Response
Limitations
• Pile head needs to be accessible and in
good condition
• Limited info on pile toe
• Depth Limitation approx 25 diameters
• Not possible if connected to other
structures
• No information on performance under
load
• Unlikely to detect defects less than 10%
section
©Strainstall 2016
Session One: Parallel Seismic
©Strainstall 2016
Session One: Parallel Seismic
PARAS Pile Integrity Tester
©Strainstall 2016
Applications
Determine depth of
existing connected
foundations
Session One: Parallel Seismic
©Strainstall 2016
Applications
Can be used where low
strain PIT will not work,
i.e. sheets piling
Session One: Parallel Seismic
©Strainstall 2016
How does it work?
• Install tube within 500m of pile
and beyond expected depth
• Grouted tube in place
• Fill with water
• Lower sensor on 0.5m
increments
• Impact structure with
instrumented hammer
• Measure transit time of signal
Session One: Parallel Seismic
©Strainstall 2016
Data Analysis
Individual signals are processed
and correct first arrival time
determined
Session One: Parallel Seismic
©Strainstall 2016
Depth and Soil Information
Pile depth and both soil and
concrete velocities can be
determined
Session One: Parallel Seismic
Slope 1 = 3500 m/sec
Slope 2 = 500 m/sec
Pile Toe at 12.5m
©Strainstall 2016
Case History
• Old BBC HQ, London
• Pile Depth Determination
• Bored Cast Piles
Session One: Parallel Seismic
©Strainstall 2016
Case History
Session One: Parallel Seismic
©Strainstall 2016
Case History
Session One: Parallel Seismic
©Strainstall 2016
Limitations
• Cost of tube installation can out weight cost of test
• Will only confirm continuity
• Will not detect local reductions or increases in pile section
• No information on performance
Session One: Parallel Seismic
©Strainstall 2016
Session One: Downhole Magnetometer
©Strainstall 2016
Applications
• Depth of sheets steel piles
• Depth of Steel reinforcement in foundations
• Depth of steel casings
• Location of UXO
Session One: Downhole Magnetometer
©Strainstall 2016
Methodology
• Detects changes magnetic fields perpendicular to borehole
• Ferrous material adjacent to borehole induces change in field
• Readings taken at 0.5m intervals
Session One: Downhole Magnetometer
©Strainstall 2016
Session One: Downhole Magnetometer
Case History
• Old BBC HQ
• Pile Depth Determination
• Bored Cast Piles
©Strainstall 2016
Fluxgate Magnetometer
Data Parallel Seismic Data
Session One: Downhole Magnetometer
Case History
©Strainstall 2016
Session One: Downhole Magnetometer
• Cost of tube installation can out weight cost of test
• Will not measure concrete continuity – only relative magnitude of steel present
• Will not detect local reductions or increases in pile section
• No information on performance
Limitations
©Strainstall 2016
Session One: Cross Hole Sonic Logging
©Strainstall 2016
Session One: Cross Hole Sonic Logging
SCXT3000 CSL System
©Strainstall 2016
How does it work?
The CHSL test is an ultrasonic test. It measures the time, t for an ultrasonic signal to travel
through concrete
Session One: Cross Hole Sonic Logging
Emitter Receiver t
©Strainstall 2016
The ultrasonic pulse is generated by a piezo-ceramic disc, when a high voltage (800V) is
applied across it.
The disc is exited horizontally at approx 50KHz, resulting in a horizontal displacement
Session One: Cross Hole Sonic Logging
How does it work?
©Strainstall 2016
Ceramics are encased
in plastic casings 25mm
in diameter
Session One: Cross Hole Sonic Logging
How does it work?
SCXT Probes
©Strainstall 2016
Session One: Cross Hole Sonic Logging
Emitter Receivers
The time, t will depend on the propagation velocity of the signal, c through the concrete and
the path length L
How does it work?
©Strainstall 2016
Session One: Cross Hole Sonic Logging
The propagation velocity, c is related to the properties of the concrete by:
How does it work?
c = √ E ρ
Therefore if the tube spacing is constant, then transit time t is a function of the properties of
the modulus and density concrete the signal is passing through
©Strainstall 2016
Session One: Cross Hole Sonic Logging
Transmitter Receiver
©Strainstall 2016
Session One: Cross Hole Sonic Logging
LED Display:
Profile No
Amplidude
Depth
Over speed
Warning
Buttons to Select
profiles and
control acquisition
Trigger pins
Acquisition light
SCXT3000 Winch unit
©Strainstall 2016
Session One: Cross Hole Sonic Logging
1
2
3
4
T0 T1
First Arrival Time traces
depth
H
1 - 2 2 - 3 3 - 4 4 - 1 1 - 3 2 - 4
1
2
3
4
time
2D Tomography Software
©Strainstall 2016
Session One: Cross Hole Sonic Logging
1
2
3
4
1
2
3
4
1
2
3
4
2D Tomography Software
Green areas correspond to normal FAT Values
©Strainstall 2016
Session One: Cross Hole Sonic Logging
2D Tomography Software
Red areas correspond to comparatively low FAT Values – i.e. anomalies
©Strainstall 2016
Session One: Cross Hole Sonic Logging
dept
h 1 - 2
time T0 T3
H1
H2
H3
H4
H5
T2
H1
H5
FAT to area colour conversion for trace 1 – 2.
1
2
3 4
3D Tomography Software
©Strainstall 2016
Session One: Cross Hole Sonic Logging
Assessment Criteria Recommendations
• Analysis of First Arrival Time (FAT) is of primary importance
• Increases of FAT in excess of 20% are significant
• Increases of FAT less than 10% are not significant on their own
• The effect on overall pile integrity will depend on the number of profiles affected
• Analysis of signal energy is of secondary importance – tube debonding is not a defect but
can lead to significant reduction
• It is essential to view the whole signal and waterfall plot – not just the FAT & Energy plot
©Strainstall 2016
Session One: Cross Hole Sonic Logging
Software
Demonstration
©Strainstall 2016
Session One: Thermal Integrity Profiling
©Strainstall 2016
Session One: Thermal Integrity Profiling
©Strainstall 2016
TIP Limitations
• The test ceases to provide information once the concrete starts to cool.
• There is a limited functional window of a few days, reducing with plie diameter
• shaft diameter decreases.
• Improvement in delayed strength gain due to admixtures may not be detected within
limited window.
• Poor thermal conductivity of concrete could mean problems core of shaft are not detected
by peripheral sensors
• Accurate tomographic images of the location, shape and extent of an inclusion cannot be
produced in same manner as CSL
• Unlikely to be able to detecting or delineating an inclusion at the pile toe
• Cannot correlate temperature to concrete strength as with CSL
• Cost of disposable in place TIP sensors can be high
Session One: Thermal Integrity Profiling - TIP
©Strainstall 2016
Session One: Rate of Corrosion
©Strainstall 2016
Session One: Rate of Corrosion
BGCMAP Rate of Corrosion meter
©Strainstall 2016
Session One: Rate of Corrosion
Applications
• Rate of Corrosion of steel below
ground
• Foundations
• Lamp Posts and Columns
• Transmission towers leg
foundations
©Strainstall 2016
Fe2+
Anode
Site
Cathode
Site
Iron
O2 OH-
H2O
e-
e-
e-
Corrosion Zone
Session One: Rate of Corrosion
LPR Theory
• Corrosion occurs at the anode,
where metal ions are oxidised
©Strainstall 2016
uA
BGCMap
Half Cell Electrode
mV
Session One: Rate of Corrosion
LPR Theory
• Current between electrode in
ground and steel is applied in
increments
• Changes in electric potential is
recorded
©Strainstall 2016
Session One: Rate of Corrosion
• Applied current and measured
voltage are plotted and is linear
about Free Corrosion Potential
Ecorr
• The slope is the Polarisation
Resistance Rp – from which
analysis is done
LPR Theory
©Strainstall 2016
Rp (ohm) Degree of Corrosion
19 Ohm and
Greater No Significant Corrosion Activity
9 – 18 Ohm Minor Corrosion Activity
6 - 8 Ohm On-Going Corrosion Activity
0 - 5 Ohm Significant Corrosion Activity
Session One: Rate of Corrosion
©Strainstall 2016
Icorr (mA) Degree of Corrosion
0.01 – 0.99 mA No significant corrosion
1.00 – 1.99 mA Minor Corrosion
2.00 – 2.99 mA On-Going Corrosion – Inspect
within 3 months
Greater than 3 mA Significant Corrosion – inspect
Immediately
Session One: Rate of Corrosion
©Strainstall 2016
Session One: Rate of Corrosion
Case History
• Transmission Tower Foundation
legs
• New Zealand
• Assessment of Corrosion
potential below ground
• 64No Towers assessed
©Strainstall 2016
Line Tower Ave
Icorr(mA
)
Worst
Leg
Worst
Leg
Icorr(mA
)
Assessment
BOB-
OTA C
63 4.26 D 5.78 Severe
Corrosion
BOB-
OTA C
65 1.75 D 2.89 Ongoing
Corrosion
BOB-
OTA C
64 1.66 A 2.48 Ongoing
Corrosion
BEN-HAY
A
1519 1.54 B 1.93 Minor
Corrosion
OTA-
WKN C
224 1.38 A 1.58 Minor
Corrosion
OTA-
WKN C
225 0.98 A 1.45 Minor
Corrosion
BEN-HAY
A
1513 0.91 C 1.34 Minor
Corrosion
OTA-
WKN C
223 0.83 B 1.24 Minor
Corrosion
BEN-HAY
A
1524 0.68 A 1.07 Minor
Corrosion
Session One: Rate of Corrosion
Case History
BOB-OTA C 63 leg D
©Strainstall 2016
Session One: Rate of Corrosion
LPR – Limitations
• Measurement only indicates corrosion activity at time of test
• Cannot measure corrosion that has occurred
• Can be affected by seasonal ground conditions
• Best used comparatively to identify foundations at higher risk of corrosion
©Strainstall 2016
Session TWO
The SIMBAT method for assessment of pile
performance dynamically
Iwan Jones – Technical Authority Foundation Testing
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT Dynamic Pile test system
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Extremes of SIMBAT testing
75Kg Drop Weight 30,000Kg Drop Weight 1,000Kg Drop Weight
©Strainstall 2016
• Instrument pile, impact it and gather data
• Process data to get dynamic reaction
• Convert dynamic load to static and
produce load/settlement plot
• Create model from simulation and match
displacement
• Produce static load/settlement plot form
simulation data
Session Two: SIMBAT Dynamic Pile Testing
How Does it Work ?
©Strainstall 2016
• Dynamic Performance of Piles under load
• Estimated static performance of Piles
• Permanent and elastic displacement
• Distribution of shaft resistance with depth
Session Two: SIMBAT Dynamic Pile Testing
What Can it Measure ?
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Pile Sensors
• Accelerometers and Strain Gauges
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
High Speed Theodolite
Simbat Theodolite – accurate to 0.14mm
at 5m @ 10,000Hz
SIMBAT High speed theodolite
©Strainstall 2016
Optical/Digital Theodolite
Accelerometers
Strain Gauges
SIMBAT Methodology
©Strainstall 2016
SIMBAT – Lyon, France
©Strainstall 2016
Total Force
Session Two: SIMBAT Dynamic Pile Testing
©Strainstall 2016
Velocity from downward
wave
Velocity from upward
wave (compressive
wave)
VE
LO
CIT
Y Combined Velocity
Session Two: SIMBAT Dynamic Pile Testing
©Strainstall 2016
Fo
rce
Downwards Force F
This lies midway between the total
force Ft and ZV
F = ½ (Ft + ZVt)
Session Two: SIMBAT Dynamic Pile Testing
©Strainstall 2016
Fo
rce
This is the F in a free pile.
It is shifted in time by 2l/c
and inverted.
©Strainstall 2016
Fo
rce
The difference between the
upwards force measured
and the upwards force in a
free pile is the dynamic
reaction, Rdy
Session Two: SIMBAT Dynamic Pile Testing
©Strainstall 2016
Simbat Software
Demonstration
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Table of Results
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Application of Damping Factor
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Simulation
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Simulation
• Pile head displacement as
measured by the test (Blue)
and simulated value (Red)
• Simulated Displacement is
generated from a Finite
Element model where the
pile is split into 20 horizontal
layers. For each layer the
model calculates Quake,
Viscosity and Rupture
values
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Static Load Simulation
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT Simulation
The purpose of the Simulation is twofold
• To Verify the predicted static load/settlement results obtained from the whole set of data
• To separate the soil resistances into those acting on the shaft and those acting on the toe
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT System Differences
Independent measurement of temporary & permanent displacement using high
speed Theodolite
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT System Differences
Correction of velocity integration errors using displacement data
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT System Differences
High and low strain blows to correct dynamic data without assuming J factors.
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT System Differences
Simulation is modelled on displacement which is more accurate than velocity
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Belgium Limelette Trial
Strainstall Group have attended numerous trials over the years, including one which was
organised by Professor Holeyman on behalf of the Belgian Building Research Institute.
This was an independent, blind trial and the SIMBAT system was assessed against the
standard dynamic pile testing systems manufactured by PDI and Profound system and also
against the Statnamic rapid load test system.
All dynamic tests were compared against static load tests carried out in the same field
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
4 Tonne Drop Weight
system
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Instrumenting pile
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
4 Tonne Drop Weight
system
©Strainstall 2016
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
00 500 1000 1500 2000 2500 3000 3500
Se
t m
m
Load KN
B6 Atlas
A9 Olivier
A6 Omega
C10 Atlas
A7 Olivier
B8 Prefab
A10 Fundex
B10 Omega
B9 Prefab
B7 De Waal
C9 De Waal
A8 Fundex
56
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Predictions
©Strainstall 2016
OLIVIER PILES
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
0 1000 2000 3000 4000
Load KN
Pile
he
ad
se
ttle
me
nt
(mm
)
A9 Simbat
A7 Simbat
A2 Static
C2 Static
C8 Statnamic
Notes: Static
load test reload
cycles omitted
for clarity. Pile
C2 ruptured at
2690KN
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Predictions
©Strainstall 2016
OMEGA PILES
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
0 1000 2000 3000 4000
Load KN
Pile
He
ad
se
ttle
me
nt
(mm
)
A6 Simbat
B10 Simbat
A3 Static
C3 Static
C7 Statnamic
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Predictions
©Strainstall 2016
PREFAB PILES
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
0 1000 2000 3000 4000
Load KN
Pile
He
ad
se
ttle
me
nt
(mm
)
B8 Simbat
B9 Simbat
B1 Static
B2 Static
C6 Statnamic
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Predictions
©Strainstall 2016
FUNDEX PILES
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
0 1000 2000 3000 4000
Load KN
Pil
e H
ead
sett
lem
en
t (m
m)
A8 Simbat
A10 Simbat
A1 Static
C1 Static
A5 Statnamic
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Predictions
©Strainstall 2016
DE WAAL PILES
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
0 1000 2000 3000 4000
Load KN
Pile
He
ad
se
ttle
me
nt
(mm
)
B7 Simbat
C9 Simbat
A4 Static
C4 Static
C5 Statnamic
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial
Predictions
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Case History: Belgium Limelette Trial Conclusions
• Simbat accurate to within 11% of Static load
• Statnamic accurate to within 12% of static load
• Other Dynamic tests varied by up to 40% !
• Trail concluded that “based on dynamic
measurements SIMBAT predictions can be
considered as the fittest for all piles”
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT Sites
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT Sites
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Key Advantages of SIMBAT System
• SIMBAT Accuracy can be comparable with Rapid Load testing
• SIMBAT testing rate is considerably higher than Rapid LT and
comparable with dynamic
• SIMBAT testing is cost effective compared to static testing
• SIMBAT test size is not limited by specialist drop weight system
• SIMBAT permanent and elastic displacement is recorded remotely
and accurately
• SIMBAT testing is less likely to damage working piles due to the
large cushion used
• SIMBAT testing can be carried out without assuming soil damping
factors
• Minimal disruption to site activity
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Acceptance & Standards
• SIMBAT is widely used on projects in the UK
• Over 1500 Simbat tests carried out last year by Strainstall group
alone
• Widely Accepted by consultants, contractors & building control
• Conforms to the ASTM standards for dynamic testing (D4945-12)
with minor differences but with additional features
• SIMBAT is included in ICE Manual of Geotechnical Engineering
• The SIMBAT methodology is in the process of being written into a
new EN ISO 22477 standard covering dynamic pile testing as a
specific annex.
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
SIMBAT Limitations
• Not designed for pile driving analysis.
• Not often used in marine environment due to requirement of stable
platform for theodolite.
• Cannot take into account long term effects such as creep, but then
neither can other dynamic or rapid load testing
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Applied Load Duration Time Comparison
• Low strain pile integrity test 1ms
• Dynamic pile test PDA 5ms
• Simbat dynamic pile test 10ms
• Rapid dynamic pile test 60ms
• Statnamic dynamic load test 120ms
• CRP pile test 1hr
• Static Load pile test 19hr
• Building life 50 years
©Strainstall 2016
Session Two: SIMBAT Dynamic Pile Testing
Pile Testing Methods Applied Load Duration Time
Log Scale
©Strainstall 2016
Huw Williams - Product Manager Foundation Testing
Iwan Jones – Technical Authority Foundation Testing
Strainstall
No. 1 Bukit Batok Crescent
#04-33 WCEGA Plaza Singapore
658064
Tel: +65 6561 4628
Questions Please!