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Transcript of Pile Design from Constructability Perspective - SEAOG · Pile Design from Constructability...
Pile Design from Constructability Perspective
Prestressed Concrete Piles in Coastal Georgia
Presented by:
Guoming Lin, Ph.D., G.E., D.GE
Senior Principal / Senior Consultant
Savannah, Georgia
November 8, 2017
Outline
Geology and Geotechnical Challenges
Prestressed Concrete Piles in the Marl
o Marl Formation
o Driveability and Driving Stresses
o Setup and Freeze Bearing
Project Case History
o Georgia Ports Container Berth 8
o Truman Parkway Phase V
o Kinder Morgan Elba Island Terminal
Summary & Conclusions
Savannah is in Coastal Plain
Bedrock 1500 - 2000 ft deep
Three Geology Regions
Blue Ridge
Piedmont
Coastal Plain
Soil Strata in Savannah
Ref: Dames & Moore “ Talmadge Memorial Bridge Foundation Load Testing Report” Sept 1985.
Soft Clay Sand
Soft Limestone
Marl Formation
Silty Clay Sand
380’ boring
Floridian Limestone
SPT SamplesNo Rock Core
Soft Clay
Sand
Marl Formation
Soil Profile in upper 150 ft boring
Supported on 6 piles
Ground settled >12 inches below pile-supported building
Restroom for Hutchinson Island Golf
Elba LNG Terminal Administration Building
A new step every 5 yearsBuilding Constructed in 1975
Photo taken in 2002
Martin Marietta Aggregates / Marine Terminal
Soils have consistency close to peanut butter
Soil Bearing Failure/Mud Wave
Outline
Geology and Geotechnical Challenges
Prestressed Concrete Piles in the Marl
o Marl Formation
o Driveability and Driving Stresses
o Setup and Freeze Bearing
Project Case History
o Georgia Ports Container Berth 8
o Truman Parkway Phase V
o Kinder Morgan Elba Island Terminal
Summary & Conclusions
Prestressed concrete piles
o Most commonly used along the Savannah River, Why?
All piles are supported in the Marl
o What is Marl?
o Driveability and Driving Stresses
o Setup and Freeze Bearing
PSC Piles
Advantages
Quality and reliability
Local experience
Corrosion resistant
Cost: less expensive
than steel H piles or
pipe piles or drilled
shafts
Disadvantages
Heavy to transport and
handle
Difficult to adjust length
Cost: more expensive
than timber pile, auger
cast piles
Marl
Loose or crumbling earthy
deposit (as of sand, silt, or clay)
that contains a substantial
amount of calcium carbonate
Miocene Formation-(5 to 23
million years ago)
Olive green and gray color
Marl
Marl, Origin and Characteristics
The Cooper Marl*
Skeletal remains of microscopic sea
organisms
Apparent over-consolidation due to
cementation
Uniform across the area
Constant properties along depth
SPT N=10 to 20, CPT tip qT~50 tsf,
VS~1500 fps, SU~4 ksf
* ref: W.M. Camp (2002) “Drilled and Driven
Foundation Behavior in Calcareous Clay” Proc.
GeoCongress, Orlando, FL.
Difference of Savannah Marl
Higher sand content
Less calcareous
Denser, SPT N=15 to 50, CPT tip qT~50 to
100 tsf
Pile driving difficulties: high blow counts
and limited penetration
High driving stresses and pile damage
Dense sandy silty claycan be excavated
imperious
Marl, Excavated at
SHEP Upper Water Intake Structure
Rincon, Georgia
PSC Pile Behaviors in the Marl in Savannah
High side frication capacities
High pore pressure (CPT or pile driving)
Setup/freeze effect
Low compressibility/settlement
Limited penetration
High driving stresses (~hammer)
Outline
Geology and Geotechnical Challenges
Prestressed Concrete Piles in the Marl
o Marl Formation
o Driveability and Driving Stresses
o Setup and Freeze Bearing
Project Case History
o Georgia Ports Container Berth 8
o Truman Parkway Phase V
o Kinder Morgan Elba Island Terminal
Summary & Conclusions
GPA Container Berth 8
Kinder MorganElba Island Terminal
Truman ParkwayPhase V
Three Case Histories
Georgia Ports Garden City Terminal
The longest contiguous berth in the US
CB8 and 9
• Construction: barge mounted cranes
• Pile driving rig with swing lead
• Rigid steel framed templates
Dock: 1700 ft long
Subsurface Profile
Marl (silty sand clay, CL/CH)
SPT N ~ 20 to 60
+15, Top of dock
-16, Top of marl, undredged
-48, Dredge depth
+10, Ground surface on land
Ref: Lockwood Greene, GPA Container Berth 8 Dock, Aug 2003.
Pile Design
• Sizes: 20”, 18”, 16” square PSC
• Length: 60 to 98 ft
• Compression Capacities: 100 to 135 tons
Pile Test Program
• 11 Indicator piles with PDA testing
• PDA testing: initial driving, 6 or 7 day restrike
• Static Load Testing:
• 2 Compression tests
• 1 Tension test
Pile Test Results-Driveability and Stresses
Pile Hammer
• Model APE 46-32
• Rated Energy: 107.2 kips-ft
• Ram Weight: 10.1 kips
• Pile cushion: 9” thick plywood
Pile Casting Details
• 7000 psi concrete (actual>10,000 psi)
• 1000 psi effective prestressing
• Allowable Stress: compressive: 4.95 ksi
• Allowable Stress: tensile: 1.25 ksi
Driving Resistances (blow counts):
• 10 to 45 bpf in the marl
• Occasionally > 50 bpf in dense layers
• All driven to tip elevations
• No pile damage observed
Driving Stresses:
• Compressive: 2.4 to 4.7 ksi
• Tensile: 0.5 to 1.2 ksi
• Lower fuel setting to 2 to reduce driving
stresses
Pile Test Results-Pile Capacities
Max Load=360 tonsMax deflection=0.40 inchesPile did not fail
Max Load=440 tonsMax deflection=0.41 inchesPile did not fail
Pile Test Results-Setup Effect and Capacity Increases
Pile Capacity (tons)
Test Pile End of Initial Drive 6D/7D Restrike Increase (tons) Percent
IP4 (E-76) 368 412 192 52%
IP5 (E-66) 276 423 147 53%
IP6 (A-53) 264 493 229 87%
IP7 (A-18) 226 539 313 139%
IP8 (F-52) 248 486 238 96%
IP9 (P-39.7) 258 525 266 103%
IP10 (D-38) 140 256 115 82%
IP11 (E-24) 193 332 139 72%
IP12 (D-4) 247 277 29 12%
IP13 (F.5-61) 199 368 169 85%
IP14 (G-31) 253 526 273 108%
Average 192 81%
Piles at CB8
Over 2,000 Piles
Vertical and Horizontal Tolerance (rigid template)
Only One Pile Damaged
GPA Container Berth 8
Kinder MorganElba Island Terminal
Truman ParkwayPhase V
Three Case Histories
Truman Parkway V
Marsh and Vernon River
$72 million
1782 piles
16” for end bents
18” for intermediate bents
Design Load: 80 tons compression
Pile Casting Details-GDOT Standards
• 5000 psi concrete
• 734 psi prestressing
• Allowable Stress: compressive: 3.6 ksi
• Allowable Stress: tensile: 0.9 ksi
Pile Hammer
• Model ICE I-30
• Rated Energy: 71.7 kips-ft
• Ram Weight: 6.6 kips
• Pile cushion: 8” thick plywood
BFI Report
• Min tip elevation=-12 to -16 m
• Estimated tip elevation=-17 m
Pile Testing and Driving Conditions
Pile Testing:
• 17 probe piles along alignment
• GDOT does not require continuous monitoring
• End of Driving Blow Count as acceptance criteria
Driving Resistances (blow counts):
• Mostly normal driving, achieved the required bearing
• Occasionally > 50 bpf in dense layers
• Min tip was adjusted to -13 meters for a few bends
Truman Parkway Phase V
Pile Damage due to Tensile Driving Stress
PDA Testing and Driving Stresses
PDA Testing:
• Bent 44, 18” Square, 73.8 ft long and tip -12.1 m (-40 ft)
• CAPWAP Capacity 312 tons
Driving Stresses:
• Max compression stress: 3.0 ksi
• Max tension stress: 0.7 ksi
• Pile driving procedures were adjusted to avoid driving damage
GPA Container Berth 8
Kinder MorganElba Island Terminal
Truman ParkwayPhase V
Three Case Histories
Elba Island LNG Terminal
20,000 piles at the terminal>9,000 piles in current phase
SPT, CPT and DMT within 5 ft at Tank Center
Comparison of SPT, CPT and DMT Soundings
Comparison of SPT, CPT and DMT at Tank Center
T5B5 T5C5 T5D1SPTCPT DMT
Static Load Test-Setup
Static Test-Load Deflection Curves
Pile Instrumentation Plan
Piles cast at Standard Concrete ProductsSavannah, Georgia
Static Test-Unit Side Friction
Pile Driving Stressesand Damage
PDA Monitor
Test Pile No.
TypeAxial Load Test Results (tons)
EOD1 4DR2 6DSTN3
12DSLT4
TP1 18-in sq PPC 186 321 447
TP2 18-in sq PPC 189 316 373 425
TP3 17.7 in dia. ICP 123 322 430
TP4 18-in sq PPC Not Tested
TP5 18-in sq PPC 200 230
Axial Capacity Testing Program Summary.NOTES:
•EOD = End Of Driving (Dynamic)
•4DR = 4 Day Restrike (Dynamic)
•6D STN = 6 Day STATNAMIC test – SLD capacity
•12D SLT = 12 Day Static Load Test
Pile Setup Effect (Strength Gain over Time)
Average increases: 4 days=70%; 6 days=151%
Pile Driving Sequence
Started with peripheral rings
Over-densified sand layers
Predrilling required to complete pile driving
Liq
uid
Le
ve
l =
11
3 ft
Inner diameter = 252 ft
Outer diameter = 258 ft
68 ft 1600 18-inch Square
prestressed concrete piles
Elba Liquefaction Project (on-going)
• $2.4 billion project to convert the terminal into an LNG export facility
• 10 MMLS (movable modular liquefaction system)
• >9,000 prestressed concrete piles
Pile Test Program
• Prestressed concrete piles (18” and 14” square)
• Steel H piles
• Three types of auger cast piles: conventional auger, displacement and partial displacement piles
Very long caseDifficult drilling
Speed !Speed !Speed !
Very large hammer
High driving stress
Green concrete
No templates
Alignment
Outline
Geology and Geotechnical Challenges
Prestressed Concrete Piles in the Marl
o Marl Formation
o Driveability and Driving Stresses
o Setup and Freeze Bearing
Project Case History
o Georgia Ports Container Berth 8
o Truman Parkway Phase V
o Kinder Morgan Elba Island Terminal
Summary & Conclusions
Conclusions
The Marl Formation is a reliable bearing stratum for piles. Marl has special
characteristics that affect pile foundation design and construction.
Prestressed concrete piles (PSC) have been the most popular foundation
system along the Savannah River.
Pile driving into the Savannah Marl can be difficult. Selection of pile hammer is
critical for pile drivability.
PSC piles are prone to damage by excessive driving stresses (compression and
tension). Using higher strength concrete and prestressing than the current
GDOT standards can help reduce the risk of pile damage.
The setup effect for PSC piles in the marl is very significant and should be taken
into account in the design and construction.
Acknowledgements
Clients: Georgia Ports, Georgia DOT, Chatham County, Kinder
Morgan
Partners: CH2M-Hill, Moffatt Nichol, Jacobs, CB&I, IHI E&C
Contractors: Orion Marine, Balfour Beatty, TIC, Bo-Mac, Cajun n
Standard Concrete Products
The Terracon Team (65+ strong in Savannah)
Thank You!
Any Questions / Comments ?
Guoming Lin, Ph.D., G.E., D.GE
Terracon Consultants
Savannah, Georgia
P: (912) 629 4000