geotechnics 2013 in the piedmont -mayne - geosystem...
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5/13/2013
1
Geotechnics 2013 in the Atlantic Piedmont Province
Paul W. Mayne, PhD, P.E.Georgia Institute of Technology
07 May 2013
The 16th Annual Sowers LectureGeorge F. Sowers(1921 – 1996)
Professor, Civil and Environmental Engineering, Georgia Tech
Senior Consultant, Law Engineering Testing Company (LETCO→ MACTEC → AMEC)
International authority:
• earth and rockfill dams• foundations• soil mechanics• engineering geology• karst limestone
• geotechnical engineering• ports and harbors• stability• residual soils• common sense
George F. Sowers 1942 – BSCE from Case Institute, Ohio
Hydraulics Engineer for Tennessee Valley Authority
US Navy from 1944 – 1946 in electronics
Married Frances Lott and together they had 4 children: Carol, Janet, Nancy, and George Jr.
Attended Harvard University with classes under:
• Karl Terzaghi
• Arthur Casagrande
• Rec’d MS in 1947
Moved to Atlanta to begin his professional career
George F. Sowers Law Engineering:
• 1955 – Vice President• 1967 – Senior VP• 1971 – Chairman of Board• 1980 – Senior Consultant
GT: 1953 – Professor CE; 1965 – Regents Professor
Member: ASCE, ISSMGE, EERI, NSPE, ASTM, SSA, AEG
Author of over 150 papers and 8 Books:
• Introduction to Soil Mechanics & Foundations (MacMillan: 1951, 1961, 1970, 1979) – English, Spanish, Chinese
• Building on Sinkholes (ASCE 1996)
Awards ‐ George F. Sowers
Engineer of the Year 1973 – GSPE
Herschel Prize 1976 – Boston SCE
ASCE Middlebrooks Award 1977
ASCE Terzaghi Lecture 1979
ASCE Martin Kapp Lecture 1985
Brooks Award in 1990
ASCE Middlebrooks Award 1994
Elected to National Academy of Engineering 1994
ASCE Terzaghi Award 1995
George F. Sowers Quotes:
Reston Dam, VA CIA, McLean, Virginia Pennfield PA
“An earth dam is likea beautiful woman…….”
“Its one dam projectafter another” “Working at the
CIA is a huge PIA”
“Using drilled shafts vs. driven pilings in karst is like
the difference of being hung or being shot. Either
way you are screwed”
Concerns after Teton Dam Failed High K0 stresses on basement walls Karst Limestone
5/13/2013
2
LETCO in Thule, Greenland 1984 1952Magnetic North Pole 1984
LETCO in Thule, GreenlandSatellite Tracking Antenna for Ford Aerospace
Jefferson Accelerator ‐ JLAB(CEBAF) – Newport News, Virginia
Nuclear physics experimental hall for study of hadrons and quarks 1800 electromagnets in an elliptical ring for high‐energy beam Tolerate only 3 mm differential between adjacent units per month
Jefferson Accelerator ‐ JLAB(CEBAF) – Newport News, Virginia Embankment
Over Tunnel
Minimize primaryconsolidation
settlements and long‐term creep
Jefferson Accelerator ‐ JLAB(CEBAF) – Newport News, Virginia
YORKTOWNFORMATION
GT Geotechnical Group"Old Highway Lab"
5/13/2013
3
Georgia Tech Geotechnical EngineeringMike Jamiolkowski(2008 Sowers Lecture)
Georgia Tech Geotechs Co‐Taught CE 6159 Rock Mechanics (1991, 1995) Textbook: Goodman, R.E. (Dick gave 3rd Sowers Lecture) Classes in Old Highway Lab Tour of rock tunnels at Duke Power Energy Station Sowers, G.F. (1996): Building on Sinkholes, ASCE Press
ASCE Interview with Professor Sowers: "How long did it take you to write this book"
George answered: "My whole life"
GT Geotechnical EngineeringMonie Ferst Award (1994) to J. Mike Duncan
Wayne Clough1st Sowers Lecture
Mike Duncan2nd Sowers Lecture
GeorgeSowers
Terzaghi Lectures by GT Geotechs
16
1979 ‐ George F. Sowers "There were Giants on the Earth in those days"
1994 ‐ G. Wayne Clough"Soft Ground Tunneling"
2014 ‐ J. Carlos SantamarinaASCE GeoCongress ‐ Atlanta
George F. SowersFamous for:
Case Studies
Lessons Learned
Importance of Engineering Geology
Practical Aspects of Geotechnical Engineering
Be careful, cautious, and stand your ground
Tell it like it is
Anecdotes
Geotechnics 2013 in the Piedmont
State‐of‐the‐Art (SOA) = What we COULD be doing: Guney Olgun
State‐of‐the‐Practice (SOP) = what we ARE doing: Ken Been
Limited time, so focus on Geocharacterizationfor Foundation Systems in the Piedmont
This talk = part SOA + part SOP → be erment
Mayne ≠ SOB
5/13/2013
4
Atlantic PiedmontGeologic Province
Surficial Extent of Appalachian Piedmont
VA‐MD‐DC
GA‐AL‐SC‐NC
Piedmont GeologicProvince
AL
GASC
NC
VA
MD DE
PA NJ
VM Quarry, I‐85
Stone MountainRed Top Mountain
Lake Lanier
Primary Rock Types by Geologic Origin
Grain
Aspects
Clastic Carbonate Foliated Massive Intrusive Extrusive
Coarse Conglomerate
Breccia
Limestone
Conglomerate
Gneiss Marble Pegmatite
Granite
Volcanic Breccia
Medium Sandstone
Siltsone
Limestone
Chalk
Schist
Phyllite
Quartzite Diorite
Diabase
Tuff
Fine‐
Grained
Shale
Mudstone
Calcareous Mudstone
Slate Amphi‐bolite
Rhyotite Basalt
Obsidian
Sedimentary Types Metaphorphic Igneous Types
PIEDMONT
GeologicTimeScale
Era Period Epoch Time Boundaries (Years Ago) Holocene - Recent Quaternary 10,000 Pleistocene 2 million Pliocene 5 million Cenozoic Miocene 26 million Tertiary Oligocene 38 million Eocene 54 million Paleocene 65 million Cretaceous 130 million Mesozoic Jurassic 185 million Triassic 230 million Permian 265 million Pennsylvanian Carboniferous 310 million Mississippian 355 million Paleozoic Devonian 413 million Silurian 425 million Ordovician 475 million Cambrian 570 million Precambrian 3.9 billion Earth Beginning 4.7 billion
PiedmontGneiss
and Schist
PiedmontGranite
Z‐Age ≈ 1 billion years ago
Piedmont Residuum: a.k.a. “Georgia Red Clay”
5/13/2013
5
Piedmont Subsurface Profile
"Georgia Red Clay"(CL ‐ML)
RESIDUUM (ML to SM)
SAPROLITE
Partially‐WeatheredRock (PWR)
Intact Rock: GneissSchist, Granite
GT Load Test Site, West Campus
0
10
20
30
40
50
60
70
80
0 10 20 30 40 50 60 70 80 90 100
SPT N-values (bpf)
Dep
th (fe
et)
GRANITIC GNEISS
Piedmont Residuum:Silty Fine Sand (SM)
PWR
Major Rock Formations in USA
Piedmont
In‐Situ Testing in the Piedmont• SPT = standard penetration testing
• PMT = pressuremeter testing
• DP = dynamic penetrometers
• percussive soundings (air‐track)
• VST = vane shear testing
• DMT = flat plate dilatometer
• CPT = cone penetration testing
• CPTu = piezocone testing
• Vs = shear wave velocity
• SCPTu = seismic piezocone
• SDMT = seismic dilatometer
Miller & Sowers (1967). Shear characteristics of
Piedmont soils using rotating vanes
SCPTU in Piedmont residual siltsWinston‐Salem, NC
Fairfax Hospital, Northern Virginia (1984)Case Study: Drilled shaft (L = 65' and d = 3') in Piedmont residuum
5/13/2013
6
Axial Pile Influence Factors (Rigid Pile)
Randolph & Wroth (1979); Poulos & Davis (1980)
Rigid Pile in an Infinite Elastic Medium
0.01
0.10
1.00
0 10 20 30 40 50 60 70 80 90 100
Slenderness Ratio, L/d
Infl
uen
ce F
act
or,
I o
Boundary Elements
Closed Form v = 0.5
Closed Form v = 0.2
Closed Form v = 0s
ptt Ed
IPw
Poulos & Davis (1980) Solution vs. Randolph Solution
Pt = load at top = Ps + Pb
Homogeneous Soil: Es = Elastic modulus' = Poisson's ratio
RIGID PILE RESPONSELength L and diameter d
Side Load, Ps= Pt ‐ Pb
Top Displacement, wt
s
tt Ed
IPw
Load Transfered to Base:
)]1)(/(5ln[)/(
)1(1
11
2 vdLdL
I
21
I
P
P
t
bPb = Base load
Ground Surface
Randolph Solution
Fairfax Hospital, Northern Virginia
s
ptt Ed
IPw
E' ≈ ED (ave. 64 DMTs) = 35 MPa = 364 tsfL = 65 feet and d = 3 feetRatio L/d = 21.7 Ip = 0.076
Buildings on Piedmont ‐ Northern Virginia and Washington DC
DMT‐SPT Correlation in Piedmont Residuum(Mayne & Frost, TRR 1988) Also EPRI Manual (1990)
Foundation Systems in the Piedmont Spread footings
Mat foundations
Augercast pilings
Drilled shafts
Micropiles
Driven pipe piles
H‐pilings
Monotubes
Step‐taper piles
Franki piles (PIFs)
5/13/2013
7
Case Study: First American Bank, Northern Virginia Case Study: First American Bank, Northern Virginia
Franki Piles, a.k.a. "Pressure Injected Footings"
Compacted Bulbof Zero‐SlumpConcrete
Pipe Casing
Concrete Shaft
Base
Case Study: Lincoln Center, Fairfax County, VA
150 Franki Piles Installed
Load Test → 5" settlement
Mat Foundation (raft)
Geotechnical Meeting• Dames & Moore• Law Engineering• Woodward-Clyde• Schnabel Engineering• ASCE National
Geotechnical Section
• No more PIFs in NoVA• Also, no law suit
First AmericanBank Mat
22-story Bank Building - Mat Foundation Tysons Corner, Virginia
0
50
100
150
200
0 50 100 150 200
West Side (feet)
No
rth
Sid
e (
feet
)
Structural ReinforcedConcrete Mat Foundation: t = 4.5 feet
Foundation Perimeter
Bank Tower:Total Q = 73,400k
Bearing Elev = +495 feet mslMat Thickness, t = 4.5 ftApplied Stress: q = 3.47 ksf
Georgia Tech
Wachovia/Wells FargoTysons Corner, VA
PREDICTED
Corner
Edge
Center
5/13/2013
8
Georgia Tech
GSU Dormitory B Settlements
0
1
2
0 1 2 3 4 5 6
Finite Layer Thickness, h/d
Influe
nce
Fact
or, I H
d
c
c/d10 5 3 21.5 1
Harr (1966)Approximation
s
Hc E
IdqDeflectionCenter
)1(:
2
c
Dormitory B Settlement Contours
0
5
10
15
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105
Breadth Distance (m)
Wid
th D
ista
nce
(m)
100 mm 120 mm 140 mm 160 mm
180 mm 200 mm 220 mm 240 mm
North
Reinforced Concrete Mat Foundation: c = 105 m; d = 18.3 m, thickness t = 1.07 m
0
50
100
150
200
250
300
0 10 20 30 40 50 60 70 80 90 100
Distance (meters)
Set
tle
me
nt
(mm
)
SW-NE DiagonalNW-SE DiagonalDMT Calculated (h = 12 m)DMT Calculated (h = 18 m)DMT Calculated (h = 24 m)
10" mat settlements DMT ED = 85 tsfwww.geoengineer.org
Elastic Solution for Foundation Displacement
0
2 )1(
s
EFGHecenter E
IIIdqs
q = applied surface stress
de = equiv. footing width
IGH = displacement influence factor
IF = foundation rigidity factor
IE = embedment factor
= Poisson’s ratio Es0 = soil modulus (bearing elev)
(Mayne and Poulos, JGGE 1999, 2001)
Harry Poulos(2002 Sowers Lecture)
Closed‐Form Solution for Finite Gibson Soil (Elhakim, 2005)
*22
*41sinh
2
1sinh
)14(
8
1*4)14(
*22
14
2
1*4*22
*22ln 11
5.12
3
2222 h
h
h
h
hh
hIG
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0.01 0.1 1 10 100
Normalized Gibson Modulus, =E o /(k E d)
Dis
pla
cem
ent
Infl
uen
ce F
acto
r, I G
h/d = 0.5
h/d = 1
h/d = 2
h/d = 5h/d = 10h/d > 30
h/d = 0.2
Mayne & Poulos, 1999 - dotsClosed-Form Solution - lines
so
o
E
qdIs
)1( 2
ADSC‐ASCE‐FHWA Load Test Program Georgia Tech, Atlanta
Load Tests
End‐bearing drilled shaft: d = 0.76 m L = 19.2 m
Friction‐type drilled shaft: d = 0.76 m L = 16.9 m
Deep plate load test: d = 0.61 m z = 16.9 m
GT End‐Bearing Shaft C1: d = 2.5' by L = 70'
Axial Load Transfer Distribution
0
10
20
30
40
50
60
70
80
0 200 400 600 800 1000
Axial Load, Q (tons)
Dep
th (
feet
)
50 tons
100 tons
200 tons
300 tons
400 tons
500 tons
600 tons
700 tons
800 tons
900 tons
1000 tonsBas
LOAD Q
Base
Elastic Continuum Response ‐ GT Shaft C1
0
10
20
30
0 2000 4000 6000 8000 10000
Axial Load, Q (kN)
Top
Def
lect
ion,
wt (m
m)
Qtotal = Qs + Qb Pred. Qs Pred. Qb
Meas. Total Meas. Shaft Meas. Base
5/13/2013
9
GT Friction Shaft C2: d = 2.5' by L = 55'
0
10
20
30
40
50
60
0 100 200 300 400 500 600
Axial Load, Q (tons)
Dep
th (
feet
)
25 tons
50 tons
75 tons
100 tons
150 tons
200 tons
300 tons
350 tons
450 tons
500 tons
Base
LOAD Q
Axial Load Transfer Distribution
BASE
Elastic Continuum Response ‐ Shaft C2
0
50
100
150
200
0 1000 2000 3000 4000 5000 6000
Axial Load, Q (kN)
Top
Def
lect
ion,
wt (m
m)
Qtotal = Qs + Qb Pred. Qs Pred. Qb
Meas. Total Meas. Shaft Meas. Base
Cone Penetration Tests (CPT) at GT West Campus
0
2
4
6
8
10
12
14
16
18
20
0 2 4 6 8 10
De
pth
(m
)
qt (MPa)
0
2
4
6
8
10
12
14
16
18
20
0 100 200 300
fs (kPa)
0
2
4
6
8
10
12
14
16
18
20
0 1 2 3 4 5 6
FR = fs/qt (%)
qt
fs
Continuous Readings at20 mm/s
CPT• Current Phase Tranformer
• Cross Product Team
• Cellular Paging Teleservice
• Chest Percussion Therapy
• Crisis Planning Team
• Consumer Protection Trends
• Computer Placement Test
• Current Procedural Terminolgy
• Cost Per Treatment
• Choroid Plexus Tumor
• Cardiopulmonary Physical Therapy
• Corrugated Plastic Tubing
• Cumulative Price Threshold
• Cell Prepartion Tube
• Central Payment Tool
• Certified Proctology Technologist
• Cockpit Procedures Trainer
• Cone Penetration Test
• Color Picture Tube
• Critical Pitting Temperature
• Certified Phelbotomy Technician
• Control Power Transformer
• Cost Production Team
• Channel Product Table
• Conditional Probability Table
• Command Post Terminal
ADSC Load Test at West GT Campus
0
2
4
6
8
10
12
14
20 30 40 50 60
Effective Stress Friction Angle, ' (deg)
Dep
th (
met
ers)
CPT qc(K&M'90)
TriaxialTests
GT Load Test ProgramADSC‐FHWA‐ASCE
McKinney Drilling
Long Foundation
Georgia Tech
ADSC
FHWA
Russo Corporation
Georgia DOT
Law Engineering‐MACTEC‐AMEC
Golder Associates
GeoSyntec Consultants
Johnson Drilling
AT&E (QORE)
Dames & Moore (URS)
CH2M‐Hill
Coastal Caisson
Allied Fence Company
Chatham Brothers
McLean‐Behm
R.H. Harris Inc.
Stan Agee Company
Thomas Concrete Inc.
Vulcan Materials
ATEC Consultants (ATC)
Georgia Power
Tensar Corporation
Turner Engineering
W.T. Mayfield & Sons
Brainerd‐Kilman
5/13/2013
10
CPT‐SPT Trend in Piedmont Residuum
0
2
4
6
8
10
12
14
16
0 10 20 30 40Penetration Value
DEP
TH (met
ers)
SPT-N (bpf)
CPT: 3 qt (MPa)
qt (bars) 3.3 N
CPT‐SPT Interrelationship in Piedmont
GeorgiaAlabama
qt/N
60(atm
/bpf)
Kulhawy & Mayne 1990
Mean Grain Size, D50 (mm)
CPT‐DMT Interrelationships in Piedmont 0 0
10000 50000
0
10000
20000
30000
40000
50000
0 2000 4000 6000 8000 10000
CPT Tip Stress, qt (kPa)
DM
T M
od
ulu
s, E
D
(kP
a) GA
AL
NC
ED = 5 qt
Opelika National GeotechnicalExperimentation Site, Alabama
Preconsolidation Stress from ConsolidometerPiedmont Silt, Opelika, Alabama (Mayne & Brown 2003)
?
Generalized Pc' Method for CPT in all soils
10
100
1000
10000
10 100 1000 10000 100000
Net Cone Resistance, qt - vo (kPa)
Ap
par
ent
Yie
ld S
tres
s,
p' (
kP
a)
General Trend:
p' = 0.33(qt-vo)m
Intact clays: m = 1.00 Organic clays: m = 0.90Silts: m = 0.85
Silty Sands: m = 0.80Clean Sands: m = 0.72
pp m1atm
mvotp )100/()q(33.0'
Amherst, MAWashington DCAtchafalyala LABoston Blue Clay, MAColebrook Road BCEmpire LAEvanston ILSF Bay Mud, CALower 232rd St BCPort Huron MISt. Alban, QuebecNRCC, OntarioYorktown VASt.Jean Vianney, QESurry, VABaton Rouge, LAStrong Pit, BCOttawa STP, OntarioVarennes, QETaranto, ItalyBrent Cross UKMadingley UKSurrey UKCanons Park UKCretaceous DCBothkennarTrendStockholm SandPo River SandHolmen SandNorth Sea SandHibernia SandTrend 2Opelika Sandy SiltTrend 3Rio de JaneiroAtlanta Silty SandPentre SiltDutch PeatEuripides Silty SandTrend 4Trend
5/13/2013
11
Apparent OCR Profiles at Opelika
0
1
2
3
4
5
6
7
8
9
10
11
12
0 1 2 3 4 5 6 7 8 9 10
Yield Stress Ratio, YSR
Oedometer
Groundwater Lowered to 20 m
Disturbed sample
CPTU
0
1
2
3
4
5
6
7
8
9
10
11
12
0 100 200 300 400
Apparent Yield Stress, y' (kPa)
Dep
th (
met
ers)
silts: p' = 0.33(qtnet)0.85 (0.1∙atm) 0.15
Cone Trucks at Opelika NGES
A.P. Van Den Berg (Morris Shea) Hogentogler (Williams Earth Sciences)
Fugro Geosciences Pagani Rig (WPC) GeoStar (Georgia Tech)
Dielectric Piezocone Sounding at Opelika
Digital Oscilloscope
Control Panel
Nitrogen Tank
0
5
10
15
20
25
30
35
0 10 20qt (MPa)
De
pth
BG
S (
m)
0
5
10
15
20
25
30
35
0 300 600fs (kPa)
0
5
10
15
20
25
30
35
-100 200 500u2 (kPa)
0
5
10
15
20
25
30
35
0.5 1DEM, e
60o
qc
fs
u2
DEM
Piezocone Response in the Piedmont
0
1
2
3
4
5
6
7
8
9
10
0 2 4 6 8 10
Depth (meters)
Cone Tip Resistanceqt (MPa)
0
1
2
3
4
5
6
7
8
9
10
0 100 200 300 400
Sleeve Frictionfs (kPa)
0
1
2
3
4
5
6
7
8
9
10
-100 0 100 200
Porewater Pressureu2 (kPa)
0
1
2
3
4
5
6
7
8
9
10
0 500 1000 1500
Porewater Pressureu1 (kPa)
qt
u1
u2
fs
Height ofCapillarity
Piezo‐Dissipation in Piedmont ResiduumLAB TESTING
Grain size Hydrometer Plasticity indices Unit weights Triaxial shear (CIUC, CIDC) Direct shear, UU, and UC Fixed wall permeameter Flex‐wall permeability Resonant column tests One‐dim consolidation
IN‐SITU TESTING and GEOPHYSICS
Standard penetration tests (SPT) Full‐displacement pressuremeter (FDPMT)
Menard pre‐bored pressuremeter (PMT)
Flat plate dilatometer tests (DMT)
Cone penetration tests (CPT) Piezocone tests with dissipations (CPTù) Seismic dilatometer tests (SDMT)
Dual element piezocones (CPTu1u2)
Resistivity cones (RCPTu) Seismic piezocones (SCPTu)
Dielectric cones (DCPTu) Borehole shear tests (IBST) Geophysical crosshole tests (CHT) Spectral analysis of surface waves (SASW)
Torque measurements following SPT
Penetration rate effects studies
Frequent interval Vs profiling
Surface resistivity surveys
FULL‐SCALE LOAD TESTS Drilled shaft foundations Axial tests on drilled shafts Lateral tests on drilled shafts Time and construction effects studies Driven pipe piles at varied rates De Waal piles Lateral loading testing of pile groups Shafts with self‐compacting concrete
Opelika NGES, Alabama ‐ Piedmont Residuum
5/13/2013
12
CPTu in Piedmont PWR‐ Atlanta, GA
SPTN6023
34
71
34
56
67
50/6"
50/6"
50/2"
50/3"
0
2
4
6
8
10
12
14
0 10 20 30 40 50 60
qT (MPa)
Dep
th (
m)
0 0.2 0.4 0.6 0.8 1
fs (MPa)
-0.1 -0.05 0 0.05 0.1
u2 (MPa)
Partially‐
Weathered
Rock
(gneiss)
Saprolite
(hard fine
sandy silt)
Residuum:
silty fine
sand
Combo CPT‐Drill Rig
CPTDrill/SPT
SCPTU in Piedmont residual siltsWinston‐Salem, NC
Geotechnics 2013 in the Piedmont
More Measurements
is
More Better
Mas Mejor
Seismic Piezocone (SCPTu)Piedmont silts in Marietta, GA
Tip Resistance
0
2
4
6
8
10
12
14
16
18
20
22
24
0 10 20 30
qT (MPa)
Dep
th (
m)
Sleeve Friction
0 200 400 600
fs (kPa)
Porewater Pressure
-100 0 100 200
u2 (kPa)
Shear Wave Velocity
0 100 200 300 400 500
Vs (m/s)
Vs
fs
u2
qt
u0
Ken Stokoe2004 Sowers
Lecture
In‐Situ QA/QC Testing for Dynamic Compaction
Hartsfield Airport Runway 5
5/13/2013
13
SCPTù at Atlanta Airport Runway 5
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
0 5 10 15 20
qT (MPa)
Dep
th (
m)
0 200 400 600
fs (kPa)
-100 0 100 200 300
ub (kPa)
0 100 200 300 400
Vs (m/s)t50 (seconds)
1 10 100 1000
Five Independent Readings of Soil Behavior: qt, fs, ub, t50, Vs
Equivalent Modulus for Static Loading
Gmax = t Vs2
t = t/g
Emax = 2Gmax(1+)
Modulus Reduction from Laboratory Data
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Mobilized Strength, /max or q/qmax
Mo
du
lus
Red
uct
ion
, G/G
max
or
E/E
max
NC S.L.B. Sand
OC S.L.B. Sand
Hamaoka Sand
Hamaoka Sand
Toyoura Sand e = 0.67
Toyoura Sand e = 0.83
Ham River Sand
Ticino Sand
Kentucky Clayey Sand
Kaolin
Kiyohoro Silty Clay
Pisa Clay
Fujinomori Clay
Pietrafitta Clay
Thanet Clay
London Clay
Vallericca Clay
= 1/FS
Open Dots = DrainedClosed Dots= Undrained
Resonant Column Torsional Shear Triaxial Shear with
local strain measurements
Modulus Reduction Scheme (Fahey & Carter 1993)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Mobilized Stress Level, q/qmax
Mo
du
lus
Red
uct
ion
, E
/Em
ax
g = 1.0
g = 0.4
g = 0.3
g = 0.2
Note: f = 1
gqqfEE )/(1/ maxmax
= 1/FS
Equivalent Modulus for Static Monotonic Loading
• Initial Stiffness from Shear Wave Velocity (Vs)
Shear Modulus: Gmax = Vs2
Young's Modulus: Emax = 2 Gmax(1+) 0.20 at small strains
• Modified Hyperbola for Modulus Reduction (Fahey
& Carter, 1993; Mayne 2007): E/Emax = 1 – (Q/Qult)g
• Factor of Safety, FS = Qult /Q
• For uncemented, unstructured soils: g 0.3
Randolph Compressible PilesL
ptt Ed
IPw
:]1[
d
L
L
Lx
)tanh(
)1(
811)1(41
d
L
L
Lx E
)tanh(4
)1(
43
[2] Ip = x1/x3
The proportion of load transferred from the top to base:
[3] Pb/Pt = x2/x3
The proportion of load carried in side shear is:
[4] Ps/Pt = 1 - Pb/Pt
The displacement at the pile toe/base is given by:
[5] wb = wt/cosh(L)
[6] = db/d = eta factor (Note: db = base diameter, so that = 1 for straight shaft piles)[7] = EsL/Eb = xi factor (Note: = 1 for floating pile; < 1 for end-bearing pile)[8] E = Esm/EsL = rho term. The parameter can be evaluated from: E = ½(1+Es0/EsL). [9] = 2(1+)Ep/EsL = lambda factor[10] = ln{[0.25 + (2.5 E(1- ) - 0.25)] (2L/d)} = zeta factor[11] L = 2(2/)0.5 (L/d) = mu factor
)cosh(
1
)1(
42 L
x
Es = Equivalent Elastic
Soil Modulus
AXIAL PILEDISPLACEMENTS
LengthL
Diameter dEso(surface)
EsM (mid-length)
EsL (along side at tip/toe/base)
Eb (base geomaterialModulus of layer 2)
sL
tt Ed
IPw
Pt Where Ip = displacementInfluence factor fromelastic continuum theory
z = Depth
Soil Layer 1
Soil or Rock Layer 2
5/13/2013
14
Drilled Shaft C2, Georgia Tech, Atlanta
0
10
20
30
40
50
60
0 1000 2000 3000 4000
Axial Load, Q (MN)
Top
Def
lect
ion,
wt (m
m)
Qtotal = Qs + Qb Pred. Qs Pred. Qb
Meas. Total Meas. Shaft Meas. Base
D = 0.76mL = 16.9 m
Opelika NGES
Mean SCPTu ProfilesOpelika NGES, Alabama
Load Tests: Opelika, Alabama (Brown 2002)
0
5
10
15
20
25
30
0 1 2 3
Axial Load, Q (MN)To
p Def
lect
ion
(mm)
Qtotal = Qs + Qb
Pred. Qs
Pred. Qb
Meas. Total
Meas. Shaft
Meas. Base
Drilled Shaft No. 01(cased)d = 0.91 mL = 11.0 m
Q (total)
Q shaft
Q base
Drilled Shaft Load Tests: Opelika, Alabama (Brown 2002)
4 Drilled Shafts d = 0.91 mL = 11.0 m
Q (total)
Q shaft
Q base
0
20
40
60
80
100
120
0 1000 2000 3000 4000
Dis
pla
cem
ent,
s (
mm
)
Applied Load, Q (kN)
Opelika NGES
Shaft S02
Shaft S04
Shaft S07
Shaft S09
Load Test at I‐85 Bridge, Coweta County, GA
GDOT Drilled Shaft Load Test:
D = 0.91 mL = 20.1 m
Load TestDirected byMike O'Neill
5/13/2013
15
SCPTu at I‐85 Bridge, Newnan, GA
0
2
4
6
8
10
12
14
16
18
0 2 4 6 8
qT (MPa)
De
pth
(m
)
0
2
4
6
8
10
12
14
16
18
0 100 200 300
fs (kPa) Ub (kPa)
0
2
4
6
8
10
12
14
16
18
-100 0 100 200
0
2
4
6
8
10
12
14
16
18
0 100 200 300 400
Vs (m/s)
Axial Load Response of Coweta Shaft
0
10
20
30
40
50
0 2000 4000 6000 8000
Axial Load, Q (kN)
Top
Def
lect
ion,
wt (m
m) Qtotal = Qs + Qb
Pred. Qs
Pred. Qb
Meas. Total
Meas. Shaft
Meas. Base
RHYMESWITHORANGEby Hilary Price
Rock → Stone → Sand = Formation of Residuum
Saprolitic
Class “A” Prediction of Axial Pile ResponseJackson County, Georgia
Gmax from SCPTu for dynamically‐loaded block foundations
Switched to driven 273 mm diameter closed‐ended steel pipe piles: 8 < L < 18 m.
CPT qt, fs and u2 used for axial capacity and Vs for initial stiffness.
Turbine Foundations,Plant Dahlberg Power StationSouthern Companies
Courtesy Marty Meeks
Seismic Piezocone Sounding, Jackson County, GA Axial Pile Response from SCPTu, Jackson County, GA
Driven Steel Pipe Pile No. P22 (L = 9.45 m)
0
2
4
6
8
10
12
14
0 200 400 600 800 1000 1200
Axial Load, Q (kN)
Def
lect
ion,
w t
(m
m)
Predicted by SCPTuin Advance
Measured
5/13/2013
16
Axial Pile Response from SCPTu, Jackson County, GA
Driven Steel Pipe Pile No. P33 (L = 17.8 m)
0
2
4
6
8
10
12
14
0 200 400 600 800 1000 1200
Axial Load, Q (kN)
Def
lect
ion,
w t
(m
m)
Predicted in advance from SCPTU data
Measured from Load Test
92
www.hindu.com www2.dot.ca.gov
www.statnamiceurope.com
Reaction FrameDead Weight
Osterberg CellStatnamic Load Testwww.fhwa.dot.gov
Pile Load Tests
GDOT Viaduct at International Boulevard near CNN, Atlanta
Drilled Shaft Load Test
by multi‐stage O‐Cells
GT Class “A” Prediction
March 2003
GDOT Load Test for Viaduct at CNN
2.9 m
11.8 m
6.2 m
d = 1.68 m
d = 1.59 m
d = 1.44 m
Residual Soils(ML/SM)
Partially-WeatheredRock (PWR)
Stage 1 O-cell
Stage 2 O-cell
Constructed Dimensionsof Drilled Shaft
Geotechnical Site CharacterizationGDOT ‐ International Blvd.
GDOT Viaduct at CNN-International Blvd
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60 70 80 90 100 110 120
Equivalent N-value (bpf)
De
pth
(m
)
CPT equivalent N
ave CPT N
SPT N
Boring Log RecordB-5 Sta 30+306
Fill: silty sand
Brown-pink sandy SILT, v. stiff hard, soft
SAND, some silt, graymedium dense, dense
PARTIALLY-WEATHEREDROCK (sand, some silt) trace mica, dark gray to grayish brown
PARTIALLY-WEATHEREDROCK (sand, some silt) trace mica, gray to grayish white
SAND, some silt, gray
GT Seismic Piezocone Sounding (SCPTu)GDOT ‐ International Blvd.
Tip Resistance
0
2
4
6
8
10
12
14
16
18
20
22
0 10 20 30
qT (MPa)
Dep
th (
m)
Sleeve Friction
0 200 400 600 800
fs (kPa)
Porewater Pressure
-100 0 100 200
u2 (kPa)
Shear Wave velocity
0 100 200 300 400 500 600
Vs (m/s)
5/13/2013
17
Class A Prediction ‐ GDOT Bridge at CNN
GDOT International Blvd. at CNN
0
10
20
30
40
50
0 1 2 3 4 5 6 7 8 9 10 11 12
Axial Load, Q (kN)
Top
Def
lect
ion,
wt (m
m)
Qt Predicted
O-cell top down
O-cell Creep Limit
(MN)
O‐cell load tests in Piedmont rocksDrilled shafts ‐ Lawrenceville, GA (2011)
Axial Pile Capacity: Qtotal = Qsides + Qbase
Qt
Qs = ∫ fp dAs
Qb = qb ∙ Ab
unit sidefriction, fp
unit base resistance, qb
Geomaterial
Fred Kulhawy(2005 Sowers Lecture
Unit Side Friction in Drilled Shafts(Kulhawy and Phoon 1993)
0.1
1
10
100
0.1 1 10 100 1000
Unit Side resistan
ce, f
p/
atm
TC equivalent shear strength, su/atm or ½ qu/atm
Clay
Shale & Mudstone
Sandstone & Limestone
= 321
SOILS
IGM
ROCKS
Unit Side Friction in the PiedmontDrilled Shafts in Residuum, PWR, and Rock
0.1
1
10
100
0.1 1 10 100 1000
Unit Side resistan
ce, f
p/
atm
TC equivalent shear strength, su/atm or ½ qu/atm
Lawrenceville O‐Cells
ADSC at GT
Opelika NGES
SILTS
Open Symbols (Kulhawy & Phoon, 1993)
PWR
O‐Cell Elastic Solution
01
1
111o1s
1
r
L2
wrG
P
P = applied force
L = pile length
ro = pile radius
Ep = pile modulus
Gs = soil side shear modulus
= Poisson's ratio of soil
2o
2
222o2s
2
r
L2
)1(
4
wrG
P
Rigid pile or plate under compression loading
Rigid pile shaft under upward loadingupper
segment
lower segment
O‐Cell
w = pile displacement
l = Ep/GsL = soil‐pile stiffness ratio
= Gs2/Gsb (Note: floating pile: = 1)Gsb = soil modulus below pile base/toe
= ln(rm/ro) = soil zone of influencerm = L{0.25 + [2.5 (1‐) – 0.25]} = magic radius
P1 = P2
Diameterd1 = 2r1LengthL1
Diameterd2 = 2r2LengthL2
5/13/2013
18
O‐cell tests ‐ ADSC/ASCE Lawrenceville, GA
‐1.0
‐0.5
0.0
0.5
1.0
1.5
2.0
0 1000 2000 3000 4000 5000 6000
Displacement, w (inches)
Applied Load, Q (tons)
Upper Segment Base Response
Elastic Pred Upward Elastic Down Pred
‐1.0
‐0.5
0.0
0.5
1.0
1.5
2.0
2.5
0 200 400 600 800 1000 1200
Displacement, w (inches)
Applied Load, Q (tons)
Upper Segment Base Response
Elastic Pred Upward Elastic Down Pred
E' = 3500 tsf E' = 1050 tsf
Test Shaft 1 in Rock Test Shaft 2 in PWR
Application of Randolph Elastic SolutionRecommendations toGeotechnical Practice
Site Characterizationin the Piedmont
FIRMCLAY
DIRECT‐PUSH TECHNOLOGY
SDMTàVp
Vstflexp1p0
NON‐INVASIVE GEOPHYSICS
(Resistivity, Radar, Conductivity)
SCPTùVs fst50u2qt
DENSESAND
loosesand
softclay
Direct Push Borehole MethodsContinuous Push Sampling Steel mandrel with inner plastic lining (d = 35 to 70 mm) Hydraulic and/or percussive push in 3‐m strokes
www.geoprobe.com www.ams‐samplers. com boartlongyear.com
Sonic Drilling Vibrations at resonant frequency of drill pipe Fast and continuous sampling of soil and rock
Calibration of SPT Energy ‐ Auto Hammers
Manufacturer Type ID No. Mean Energy Ratio (%) Reference
Diedrich D‐120 ID 26 46 UDOTDiedrich D‐50 321870551 56 GRLCME 850 ID 21 62.7 UDOTBK‐81 w/ AW‐J rods B2 68.6 ASCEMobile B‐80 ID 18 70.4 UDOTSK w/ CME hammer B6 72.9 ASCEDiedrich D50 UF5 76 UFCME 55 UF2 78.4 FDOTCME 850 296002 79 GRLCME 45 UF1 80.7 UFCME 85 UF4 81.2 UFCME 75 w/ AW‐J rods A3 81.4 ASCECME 75 UF3 83.1 UFCME 750 ID 4 86.6 UDOTMobile B‐57 DR‐35 93 GRLCME 75 rig ID 10 94.6 UDOT
Factorof 2.1
O‐cell load tests in Piedmont rocksDrilled shafts ‐ Lawrenceville, GA (2011)
5/13/2013
19
Methods for Rating Rock Masses
Core Recovery (CR) Rock Quality Designation (RQD); Deere et al. (1966) Rock Mass Rating (RMR); Bieniawski (1976, 1989) Q‐System by NGI; Barton et al. (1976, 1991) Geological Strength Index (GSI); Hoek (1995, 2009)
Uniaxial Compressive Strength, qu Rock Quality Designation (RQD) Spacing of Joints Condition of joints and/or infilling Groundwater conditions
Rock Mass Rating (RMR)
Dick Goodman3rd Sowers
Lecture
Shear Wave Velocity Profile in Piedmont VC Summer Power Station, South Carolina
Intact Rock
CR = 98 ‐ 100%
RQD = 97 ‐ 100%
Vs = 10,100 fps = 3078 m/s
qu = 25 ksi = 170 MPa
t = 180 pcf = 28 kN/m3
Shear Wave, Vs (fps) Shear Wave, Vs (fps)
Elevation (feet msl)
Vs from suspension logging in boreholes
Field Geophysics ‐Mechanical Wave Methods
SRFS = Surface Refraction SurveySFLS = Surface Reflection SurveySASW = Spectral Analysis of Surface WavesMASW = Modal Analysis (Rayleigh Waves)CSW = Continuous Surface WavesPSW = Passive Surface Wave TestingReMi = Reflection MicroSeisSLP = Suspension Logger ProblngCHT = Crosshole TestRCHT = Rotary CrossholeDHT = Downhole TestUHT = Uphole TestSCPTu = Seismic Piezocone TestSDMT = Seismic Flat Dilatometer TestBTSD = Borehole Torsional Shear Device
Seismograph+ Source
Receivers Geophones
SFLS SFRS
RotarySource
VerticalSource
TorsionalSource
Cased Boreholes
VsHV
VsHH
VsHH
VsHH
Oscilloscope+ Source
Vp
VsVH
SpectralAnalyzer+ Source
SASW MASW CSW PSW ReMi
Rayleigh Wave Methods
CHT
RCHT
BTSD SLP
VsVV
high frequencies
medium frequencycontent
lowfrequencycontent
VsRW
DHT
UHT
Combined MASW Arrays for 2DMapping Subsurface Heterogeneity
Surface Distance (m)Shear Wave, Vs (m/s)
Dep
th (m)
courtesy: Illmar Weemees ‐ ConeTec
ReMi Mapping of Subsurface Geomaterials(Cha, Kang, and Jo, 2006: Exploration Geophysics)
ReMi = Reflection Microtremors(passive Rayleigh wave survey)
Geotechnics 2013 in the Piedmont
• Beyond conventional SPT and PMT, showed advent and value of DMT, CPT, + SCPTu, SDMT
• Elastic continuum solution for pile foundations
Static top down loading
Bi‐directional O‐cell load tests
• Fundamental soil stiffness: Gmax = Vs2
• Presented case studies in Piedmont
• Use of Rock Mass Rating (RMR)
• Recommended more use of geophysics for site characterization, particularly Vs profiling
5/13/2013
20
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