soil-pile interaction in · pdf file• nonlinear finite element analysis program ......
TRANSCRIPT
![Page 1: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/1.jpg)
Soil-Pile Interaction in
FB-MultiPier
Developed by: Florida Bridge Software Institute
Dr. J. Brian Anderson, P.E.
![Page 2: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/2.jpg)
Session Outline
• Introduce FB-MultiPier Software
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile
![Page 3: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/3.jpg)
FB-MultiPier
• Nonlinear finite element analysis program
capable of analyzing multiple bridge pier
structures interconnected by bridge spans.
• The full structure can be subject to a full
array AASHTO load types in a static
analysis or time varying load functions in a
dynamic analysis.
![Page 4: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/4.jpg)
FB-MultiPier
• Each pier structure is composed of pier
columns and cap supported on a pile cap
and piles/shafts with nonlinear soil.
• FB-Multipier couples nonlinear structural
finite element analysis with nonlinear static
soil models for axial, lateral and torsional
soil behavior to provide a robust system of
analysis for coupled bridge pier structures
and foundation systems.
![Page 5: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/5.jpg)
FB-MultiPier
• FB-MultiPier performs the generation of the
finite element model internally given the
geometric definition of the structure and
foundation system as input graphically by
the designer.
![Page 6: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/6.jpg)
Coupled Soil-Structure Interaction
Battered Piles
or Shafts
Ship Impact Ship Impact Scour
Scour
Plumb Piles/Shafts
(Shallow Water) (Deep Water)
Live and Dead Loading
Earthquake
![Page 7: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/7.jpg)
Coupled Soil-Structure Interaction
SoilSoil
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Florida Pier
![Page 9: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/9.jpg)
FB-MultiPier
![Page 10: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/10.jpg)
Florida Bride Software Institute
• FB-MultiPier and other software for bridge
analysis and design developed and
supported by BSI
• http://bsi-web.ce.ufl.edu
• Good educational discounts (free)
![Page 11: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/11.jpg)
Session Outline
• Introduce FB-MultiPier Software
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile
![Page 12: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/12.jpg)
Session Outline
• Introduce FB-MultiPier Software
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile
![Page 13: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/13.jpg)
Soil-Structure Interaction
Vertical Nonlinear Spring
Lateral Nonlinear Spring
Torsional Nonlinear Spring
Nonlinear Tip Spring
![Page 14: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/14.jpg)
Driven Piles - Axial Side Model
z r
d z
s
s
s r
s r + D s
r / D r d r
d
z
t
dr
r
t + D t / D r d r
to
r
roott
t (Randolph &
Wroth)
![Page 15: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/15.jpg)
Driven Piles - Axial Side Model
z DZ
Dr
D
D
rd
zd
r
zGt
Also:
Substitute: Grd
zdt
Rearrange: drG
dzt
Previous r
roott
Substitute: drGr
rdz o 0t
rm r0
Also:
2
f
i 1
t
tGG
Substitute:
m
0
r
r
2
f
i
0
1
dr
Gr
rz o
t
t
t
![Page 16: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/16.jpg)
Driven Piles - Axial Side Model
f
0 0
0m
0m
0
m
i
00 ,lnzt
t
t r
rr
rr
r
r
G
r
T-Z (Along Pile)
0
200
400
600
800
1000
1200
0 0.5 1 1.5
z - Displacement (inches)
Tau
0 (
psf) tf = 1000psf
Gi = 3 ksi
![Page 17: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/17.jpg)
Driven Piles - Axial Tip Model
2
f
i0P
P1Gr4
-1Pz
Where: P = Mobilized Base Load
Pf = Failure Tip Load
ro = effective pile radius
= Poisson ratio of Soil
Gi = Shear Modulus of Soil T-Z (At Tip)
0
50
100
150
200
250
300
0 1 2 3 4 5
z - Displacement (inches)
Tip
Load (
kip
s) Pf = 250 kips
Gi = 10 ksi
= 0.3
r0 = 12 inches
(Kraft, Wroth, etc.)
![Page 18: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/18.jpg)
Driven Piles - Axial Properties
• Ultimate Skin Friction (stress), Tauf , along
side of pile (input in layers).
• Ultimate Tip Resistance (Force), Pf , at pile
tip .
• Compressibility of individual soil layers,
I.e. Shear Modulus, Gi , and Poisson’s ratio,
n .
![Page 19: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/19.jpg)
Driven Piles - Axial Properties
• From Insitu Data:
– Using SPT “N” Values run SPT97, DRIVEN,
UNIPILE, etc. to Obtain: Tauf , and Pf
– Using Electric Cone Data run PL-AID, LPC,
FHWA etc. to Obtain: Tauf , and Pf
– Determine G or E from SPT correlations, i.e.
Mayne, O’Neill, etc.
![Page 20: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/20.jpg)
Florida: SPT 97 Concrete Piles
Skin Friction, tf (TSF)
• Plastic Clay:
– tf= 2N(110-N)/4006
• Sand, Silt Clay Mix:
– tf = 2N(110-N)/4583
• Clean Sand:
– tf = 0.019N
• Soft Limestone
– tf = 0.01N
Ultimate Tip, Pf/Area(tsf)
• Plastic Clay:
– q = 0.7 N
• Sand, Silt Clay Mix:
– q = 1.6 N
• Clean Sand:
– q = 3.2 N
• Soft Limestone
– q = 3.6 N
![Page 21: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/21.jpg)
API Side Friction Model - Sand
• tf = K p’0 tan d
where
• k = dimensionless coefficient of lateral earth pressure (ratio of horizontal to vertical normal effective stress(for unplugged K=0.8 and for plugged K=1.0)
• p’0 = effective overburden pressure in stress units
• δ = friction angle between the soil and pile wall, which is defined as d = f – 5o
![Page 22: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/22.jpg)
API Side Friction Model - Sand
![Page 23: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/23.jpg)
API Side Friction Model - Clay
• tf = a cu
where
• cu = undrained shear strength
• a = a dimensionless factor, which is defined as
– a = 0.5-0.5 ≤ 1.0 for ≤ 1.0
– a = 0.5-0.25 ≤ 1.0 for > 1.0
= cu/p’0
![Page 24: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/24.jpg)
API Side Friction Model - Clay
![Page 25: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/25.jpg)
API Tip Model - Sand
• q = p’0 Nq
where
– p’0 = effective overburden pressure in stress units
– Nq = eπtan(f’)tan2(45 + f’/2)
• Qp = qA
• Where
– Qp is the total end bearing capacity
– A is the cross sectional area
![Page 26: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/26.jpg)
API Tip Model Sand
![Page 27: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/27.jpg)
API Tip Model - Clay
• q = 9cu
where
• cu = undrained shear strength
• Qp = qA
where
– Qp is the total end bearing capacity
– A is the cross sectional area
![Page 28: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/28.jpg)
API Tip Model Clay
![Page 29: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/29.jpg)
Cast Insitu Axial Side and Tip Models
• For soil (sands and clays)
– Follow FHWA Drilled Shaft Manual For Sands
and Clays to Obtain Tauf and Pf ( and cu)
– Shape of T-Z cuve is given by FHWA’s Trend
Lines.
• User has Option of inputting custom T-z /
Q-z curves
![Page 30: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/30.jpg)
Cast Insitu - Sand (FHWA):
Qs = p D L sv’
D L
L/2
sv’ = L/2
1.5 .135 L/2) 0.5 1.2> >0.25
Qt = 0.6 NSPT p D 2 / 4 NSPT < 75
![Page 31: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/31.jpg)
Cast Insitu - Clay (FHWA):
D L
Qs = 0.55 Cu p D (L-5’-D)
Qt = 6 [1+0.2(L/D) ] Cu (p D 2 / 4)
![Page 32: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/32.jpg)
Cast Insitu trend line for Sand
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0 2 4 6 8 10
Settlement / Diameter (%)
Mo
bil
ize
d S
tre
ss
/ U
ltim
ate
Str
es
s
End Bearing
Side Friction
![Page 33: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/33.jpg)
Cast Insitu trend line for Clay
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0 2 4 6 8 10
Settlement / Diameter (%)
Mo
biliz
ed
Str
es
s /
Ult
imate
Str
es
s
End Bearing
Side Friction
![Page 34: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/34.jpg)
Session Outline
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile
![Page 35: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/35.jpg)
Torsional Model (Pile/Shaft)
• Hyperbolic Model
– G and Tauf
• Custom T-
![Page 36: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/36.jpg)
Torsional Model (Pile/Shaft)
(rad)
T (F-L)
Tult =1/b
(dT/d)=1/a Gi
Tult = 2p r2 D L tult T = / a + b
Tult = tf Asurf r
tult = Ultimate Axial
Skin Friction
(stress)
![Page 37: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/37.jpg)
Session Outline
• Introduce FB-MultiPier Software
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile
![Page 38: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/38.jpg)
Lateral Soil-Structure Interaction
Passive State
Active State
Y
![Page 39: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/39.jpg)
Near Field: Lateral (Piles/Shafts)
r
y
X
P r dF
Lr
s
p
0
2
P r dF
Lr
s
p
0
2
r
Y=5”
sr
sr
Y=0
P = 0 P
Y
Pu
P rStiff
Clay
Sand &
Soft Clay
PPPP
![Page 40: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/40.jpg)
P-y Curves - Reese’s Sand
k
m
b/60 3b/80
x = 0
x = x1
x = x2
x = x3
x = x4
u
p k
y k
y m
yu p m
p u
m
y
P
ks x
Pu is a function of
f, , and b
Y is a function
of b (pile diameter)
![Page 41: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/41.jpg)
0.0
0.5
1.0
PPU
y
y50
1.0 8.0
p
p0.5
y
yu 50
1 / 3
Matlock’s Soft Clay
Pu is a function of
Cu, , and b
Y is a function of
y50 (50)
![Page 42: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/42.jpg)
Reese’s Stiff Clay Below Water
Deflection, y (in.)
Soil
Res
ista
nce
, p
(lb
/in
.)
18Asy506Asy50y50Asy50
Esi = ksx
0.5Pc
0
P Pcy
y 0 5
50
0 5. ( )
.
P poffset cy A y
A ys
s
0 055 50
50
1 25. ( )
.
STATIC
Essp
yc
0 0625
50
.
Pc is a function of
C, , ks and b
Y is a function of
y50 (50)
![Page 43: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/43.jpg)
O’Neill’s Integrated Clay
Pu is a function of
c, and b
Fs is a function of 100
Yc is a function of b and 50
![Page 44: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/44.jpg)
Soil Properties for Standard Curves
• Sand:
– Angle of internal friction, f
– Total unit weight,
– Modulus of Subgrade Reaction, k
• Clay or Rock:
– Undrained Strength, Cu
– Total Unit Weight,
– Strain at 50% of Failure Stress, 50
– Optional: k, and 100
![Page 45: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/45.jpg)
Soil Information
Help Menu EPRI (Kulhawy & Mayne)
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P-y Curves from Insitu Tests
• Cone Pressuremeter
• Marchetti Dilatometer
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Insitu PMT & DMT Testing
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Cone Pressuremeter
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Cone Pressuremeter
(Robertson, Briaud, etc.)
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Marchetti Dilatometer
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Pressuremeter P-y Curves Auburn, Alabama
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 5 10 15 20 25 30 35 40
y (mm)
P (
kN
/mm
)
1 m
2 m
3 m
4 m
6 m
8 m
10 m
PMT P-y Curves - Auburn
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Dilatometer P-y Curves Auburn, Alabama
0
500
1000
1500
2000
2500
0 50 100 150 200 250 300 350
y (mm)
P(k
N/m
)
0.6 m
2.1 m
3 m
4.2 m
6.3 m
7.2 m
DMT P-y Curves - Auburn
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Actual and Predicted Lateral Top of Shaft Deflections
Auburn, Alabama
0
100
200
300
400
500
600
700
800
900
1000
0.0 10.0 20.0 30.0 40.0 50.0 60.0
Lateral Deflection (mm)
La
tera
l L
oa
d (
kN
)
PMT
DMT
CPT
Shaft 1
Shaft 2
Shaft 3
Shaft 6
Auburn Predictions
![Page 54: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/54.jpg)
P-y Curves for PMT1
Pascagoula, Mississippi
0
1
2
3
4
5
6
0 20 40 60 80 100 120 140 160 180 200
y (mm)
P (
kN
/mm
)
9.7
10.7
11.7
12.7
13.8
14.8
15.8
16.8
17.8
18.8
PMT P-y Curves Pascagoula
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P-Y Curves from DMT 1
Pascagoula, Mississippi
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 10 20 30 40 50 60
p (mm)
y (
kN
/mm
)
9.6
10.8
11.7
12.6
16.0
16.9
17.8
DMT P-y Curves Pascagoula
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Pascagoula Predictions
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 10 20 30 40 50
Deflection (mm)
Lo
ad
(kN
) DMT
PMT
Actual
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Instrumentation & Measurements
• Strain gages
– Measure strain
– Calculate bending moment, M = ε(EI/c), if EI of section known
– “high tech”
• Slope inclinometer
– Measures slope
– Relatively “low tech”
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Theoretical Pile Behavior
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
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Strain Gages Bending Moment
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Bending Moment versus Depth
0
1
2
3
4
5
6
0 200 400 600 800 1000 1200
Bending Moment (kN*m)
Dep
th (
m) 36
62
93
121
153
182
211
258
Lateral
Load in
Kilonewtons
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Bending Moment vs. Depth
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
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Two Integrals to Deflection
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
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Two Derivatives to Load
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
z
z
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Non-linear Concrete Model
Test Pile T1
0.0E+00
2.0E+05
4.0E+05
6.0E+05
8.0E+05
1.0E+06
0.0E+00 2.0E-03 4.0E-03 6.0E-03 8.0E-03 1.0E-02
Curvature, f (1/m)
EI (k
N-m
2)
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P-y Curves from Strain Gages
0
20
40
60
80
100
120
140
0 5 10 15 20 25 30 35
Displacement, y (mm)
p (
kN
/m)
1.0
2.0
3.0
4.1
D. to G.S.
(m)
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Slope Inclinometer Slope
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Deflection versus Depth
-2
0
2
4
6
8
10
-0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07
Horizontal Displacement (m)
De
pth
(m
)
36
62
90
122
153
183
208
243
Lateral
Load in
Kilonewtons
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Slope Inclinometer → Slope vs. Depth
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
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One Integral to Deflection
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
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Three Derivatives to Load
PM
Pile
Y(z)
Deflection
Y’(z)
Slope
M(z)
Moment
M’(z)
Shear
P(z)
Soil Reaction
z
z
z
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P-y Curves from Slope Inclinometer
0
20
40
60
80
100
120
140
0 5 10 15 20 25 30 35
Displacement, y (mm)
p (
kN
/m)
1.0
2.0
3.0
4.0
D. to GS
(m)
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0
20
40
60
80
0 5 10 15 20 25 30 35
Displacement, y (mm)
p (
kN
/m)
SG
inc
PMT/DMT
SPT
Comparison of P-y Curves
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Prediction of Pile Top Deflection
0
50
100
150
200
250
300
0 20 40 60 80 100
Top Displacement (mm)
Lo
ad
(k
N)
W. line
FLPIER-sg
FLPIER-inc
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P-y Curves Available in FB-Pier
• Standard
– Sand
• O’Neill
• Reese, Cox, & Koop
– Clay
• O’Neill
• Matlock Soft Clay Below Water Table
• Reese Stiff Clay Below Water Table
• Reese & Welch Stiff Clay Above Water Table
![Page 75: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/75.jpg)
P-y Curves Available in FB-Pier
• User Defined
– Pressuremeter
– Dilatometer
– Instrumentation
• Strain Gages
• Slope Inclinometer
![Page 76: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/76.jpg)
Session Outline
• Introduce FB-MultiPier Software
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile
![Page 77: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/77.jpg)
Pile Element Model
hh2
h2
X
Z
X
Y
(Top View)
(Side View)
M M
M M
1 3
2 4
Universal Joint
Rigid center-blocks
Rigid end Block
Spring
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Curvature-Strain-Stress-Moment
a) Strain due to
z-axis bending
b) Strain due to
y-axis bending
c) Strain due to
axial thrust
N
N
F
,
F
,i
i
1
2
x
y
z
dF
dA
i
i
e) Stress-strain relationship
d) Combined strains
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Stress-Strain Curves for Concrete & Steel
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Strains -> Stress -> Moments
x
y
z
dF
dA
i
i
d) Combined strains
dFi=si*dAi
n_PointsIntegratio
x ydF*M
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Stiffness of Cross-Section: Flexure, Axial
M
x
y
z
dF
dA
i
i
d) Combined strains
n_PointsIntegratio
x ydF*M
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Failure Ratio Calculation
My
Mx
P
Mxo
Myo
Pactual
Failure Ratio = Surface Length
Actual Length
![Page 83: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/83.jpg)
Pile Material Properties
![Page 84: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/84.jpg)
References:
• Robertson, P. K., Campanella, R. G., Brown, P. T., Grof, I., and Hughes, J. M., "Design of Axially and Laterally Loaded Piles Using In Situ Tests: A Case History,“ Canadian Geotechnical Journal, Vol. 22, No. 4, pp.518-527, 1985.
• Robertson, P. K., Davies, M. P., and Campanella, R. G., "Design of Laterally Loaded Driven Piles Using the Flat Dilatometer," Geotechnical Testing Journal, GTJODJ, Vol. 12, No. 1, pp. 30-38, March 1989.
• Reese, L. C., Cox, W. R. and Koop, F. D (1974). "Analysis of Laterally Loaded Piles in Sand," Paper No. OTC 2080, Proceedings, Fifth Annual Offshore Technology Conference, Houston, Texas, (GESA Report No. D-75-9).
• Hoit, M.I, McVay, M., Hays, C., Andrade, P. (1996). “Nonlinear Pile Foundation Analysis Using Florida Pier." Journal of Bridge Engineering. ASCE. Vol. 1, No. 4, pp.135-142.
• Randolph, M. and Wroth, C., 1978, “Analysis of Deformation of Vertically Loaded Piles, ASCE Journal of Geotechnical Engineering, Vol. 104, No. 12, pp. 1465-1488.
• Matlock, H., and Reese, L., 1960, “Generalized Solutions for Laterally Loaded Piles,” ASCE, Journal of Soil Mechanics and Foundations Division, Vol. 86, No. SM5, pp. 63-91.
![Page 85: Soil-Pile Interaction in · PDF file• Nonlinear finite element analysis program ... FB-MultiPier • Each pier ... • Clay or Rock: – Undrained Strength, Cu](https://reader031.vdocuments.mx/reader031/viewer/2022012405/5aaced5c7f8b9aa9488da21f/html5/thumbnails/85.jpg)
Session Outline
• Identify and Discuss Soil-Pile Interaction Models
– Precast & Cast Insitu Axial T-Z & Q-Z Models
– Torsional T- Models
– Lateral P-Y Models
– Nonlinear Pile Structural Models
• FB-MultiPier Input and Output
– Example #1 Single Pile