the coupled hydro-thermo-mechanical process in soils and
TRANSCRIPT
The Coupled Hydro-thermo-mechanical Process
in Soils and its Implications for Emerging
Geotechnical Engineering Practice
Xiong (Bill) Yu, Ph.D., P.E.
Associate Professor, Department of Civil Engineering, Case Western
Reserve University, 216-368-6247, [email protected]
Purdue Geotechnical Society Workshop
April 19, 2013
About myself
Purdue Graduate
Current program affiliation
Geotechnical engineering
Infrastructure engineering
EECS and other programs
Current research focus
Sensor technology
Field instrumentation
Durable and multifunctional civil engineering
materials
Sustainability
Energy geotechnology
Multiphysics stands for the coupling of multiple fields
Common observations in soil
Phase change of pore water involves energy significantly alter the soil
properties such as elastic modulus (hydraulic and mechanical).
Fluid transfer due to the temperature gradient (Philip, 1957; Cary,
1964). (Coupling between thermal and hydraulic)
Mechanical constraints: the mechanical field can only response partly
to the other field and thus in turn affect the other field (Mechanical on
thermal and hydraulic).
…
We are interested to explore the common scientific basis to the
multiphysics process in soils and other geomaterials
Multiphysics versus Single Field
Impacts on Engineering
Frozen soil covers 60% the earth surface
Climate effects on infrastructure
Geothermal energy
Green energy source
Gas hydrate
A huge potential energy source
Unconventional gas/oil
Utica shale in Ohio alone contains 15 trillion cubic
feet of natural gas Zhang et al. 1999
Johnson 2011 Ryder 2008
Observation 1: Thawing Soils
Volume Change Behaviors in Thawing Soils
Liu Y., Yu, et al. 2009
Thawing Soils: cont.
Component of volume change
Liu Y., Yu, et al. 2009
Observation 2: Desiccation Crack in Soil
Schematic drawing modified from internet resource
Observation 3: Plastic shrinkage of concrete
Commonly observed in fresh concrete
Accelerate deterioration
Relations between shrinkage and time for concretes stored at different
relative humidities (Troxell, Raphael, and Davis 1958). Examples of plastic shrinkage cracking (source Internet)
Shrinkage cracking mechanism (ACI 224R-01)
Chemically Treated Soils
Shrinkage Cracking Resulting from Problems with Cement-
Treated Base (internet image)
Cement treated soils
Cracks accelerate water infiltration into pavement base
Are There Common Mechanisms?
Freezing
Drying
Chemical hydration
These motivates us to explore the fundamental knowledge for porous
materials
Liquid water “consumption”?
Solid (Soil, Concrete, Ceramic, ...) Water Characteristic Curve
(SWCC)
Describes the change of matric suction with water
Decided by the pore structures
0 0.5 1 1.5 2 2.5 3 3.50
0.1
0.2
0.3
0.4
0.5
log(h) (unit of h: kPa)
Volu
metr
ic w
ate
r co
nte
nt
Base
Subgrade
Q1. Can SWCC explain the experimental observations?
Q2. If so, how to integrate into simulation modeling?
Pore space from CT scanning
Thermal (T,Ө)
Fourier’s eq.
Mechanical (u,T,Ө,h)
Navier’s eq.
Hydraulic (h,T,Ө)
Richards’ eq.
Өi
T
u
Ө
h
A multiphysical thermo-hydro-mechanical process.
i iw w( , ), ( , )C
iw( , , )K T
Ice-water balance
Clapeyron’s eq.
Freezing point
depression
Energy from phase change
iw( , )E
Volume change due to ice formation
Retention curve
th
Simulation of Freezing Soils
Three phase diagram of water
( From www1.lsbu.ac.uk )
Generalized Clapeyron equation:
(Williams and Smith, 1989)
f
w
LdP
dT V T i f
g
d L d
dT T dh
Freezing Point Depression
PDEs governing individual process Fourier’s equation, Richard’s equation, Navier’s equation
Boundary and constitutive relationships Newton’s low of cooling, Darcy’s law, mass balance, constitutive
relationships
Experimental correlations for porous media Soil water characteristic curve,
Hydraulic conductivity
Thermal conductivity
Phase transition Clapeyron’s equation for water-ice balance
Theoretical model–(PDEs-weak form)-solved numerically
Can’t go into details due to time constraints
Approach to the Problem
Lh Lh LT( ) 0K h K K T n
c emb( ) h ( )T T T n
Unsaturated uniform soil specimen subjected to surface freezing
Boundary condition
Example
0.00
0.05
0.10
0.15
0.20
0.25 0.30 0.35 0.40 0.45 0.50
0 hour
Heig
ht (m
)
0.00
0.05
0.10
0.15
0.20
0.25 0.30 0.35 0.40 0.45 0.50
12 hours
Heig
ht (m
)
0.00
0.05
0.10
0.15
0.20
0.25 0.30 0.35 0.40 0.45 0.50
24 hours
Total volumetric water content
Heig
ht (m
)
0.00
0.05
0.10
0.15
0.20
0.25 0.30 0.35 0.40 0.45 0.50
50 hours
Total volumetric water content
Heig
ht (m
)
Volumetric total water content after 0,12,24,50 hours
Results: thermally driven moisture migration
0.00
0.05
0.10
0.15
0.20
-4 -3 -2 -1 0 1 2 3 4 5 6 7
0 hour
He
ight (m
)
0.00
0.05
0.10
0.15
0.20
-4 -3 -2 -1 0 1 2 3 4 5 6 7
12 hours
He
ight (m
)
0.00
0.05
0.10
0.15
0.20
-4 -3 -2 -1 0 1 2 3 4 5 6 7
24 hours
Temperature (oC)
He
ight (m
)
0.00
0.05
0.10
0.15
0.20
-4 -3 -2 -1 0 1 2 3 4 5 6 7
50 hours
Temperature (oC)
He
ight (m
)
Temperature after 0,12,24,50 hours
0.00
0.05
0.10
0.15
0.20
0 10 20 30 40 50 60 70
0 hour
Heig
ht (m
)
0.00
0.05
0.10
0.15
0.20
0 10 20 30 40 50 60 70
12 hours
Heig
ht (m
)
0.00
0.05
0.10
0.15
0.20
0 10 20 30 40 50 60 70
24 hours
Pressure head (m)
Heig
ht (m
)
0.00
0.05
0.10
0.15
0.20
0 10 20 30 40 50 60 70
50 hours
Pressure head (m)
Heig
ht (m
)
Pore pressure head after 0,12,24 50 hours
Soil Freezing: Interesting Phenomena
Vertical deformation VS time Vertical internal stress
• Two important phenomena reproduced by the simulation.
1.0
0.8
0.6
0.4
0.2
0.00 10 20 30 40 50 60 70 80 90 100
Time (minute)A
xis
dis
pla
ce
me
nt
(mm
)
The similarity between freezing and Drying
Water
Vapor
Water
Ice
Drying Freezing
a w i wAP P P P
Koopmans (1966) and Spaans (1996)
CT imaging
Water content in drying process Unfrozen water content in freezing process (measured by TDR)
SWCC from Freezing Process?
f ln273.15
TL
Clapeyron equation (Groenevelt, 1974)
u f
% 100%t fw w
w w
wa
d
1w K a
b
a,t a,f
a,u a,f
% 100%K K
K K
22
L
L
v
cK a
a
Matric suction in drying process Temperature in freezing process (measured by thermal couples)
21
Traditional
New method
Computer
PICO TDR
Thermo-
TDR
Refrigerator (-18 degC)
Demonstration
TDR
Zhang and Yu 2009
Example Results: 1
(a) Soil # 1, Specimen #1 (b) Soil #1, Specimen #2
0.01 0.1 1 10
Stable SFC
Suction (Mpa)
Measured SWCC
0.0
0.2
0.4
0.6
0.8
1.0
Satu
ration
Modified Stable SFC
0.01 0.1 1 10
0.0
0.2
0.4
0.6
0.8
1.0
Stable SFCSa
tura
tio
n
Suction(Mpa)
Measured SWCC
Measured SFC by new method and SWCC by traditional filter paper method
23
Example Results: 2
1E-5 1E-4 1E-3 0.01 0.1 1 10 100
0.0
0.2
0.4
0.6
0.8
1.0
Stable SFC
Satu
ration
Suction (Mpa)
Measured SWCC
2 4 6 8 10 12 14 16 18
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Measured SFC of bean curd
Genuchten fit
Satu
ration
Suction (MPa)
Model Genuchten
Equation y=1/(1+(a*x)^n)^m
Parameter Fitted Value Standard Error
m 0.69123 0.23977
n 1.9782 0.28557
a 0.98565 0.27371
Figure 2 SFC and SWCC of soil #2 SFC of a slab of firm bean curd
24
Is SWCC the Ultimate Goal?
Solid, air and liquid interface
Young–Laplace equation Young’s equation
Is SWCC the Ultimate Goal? (cont.)
Water Characteristic Curve
SWCC Key concept of porous geomaterials
Pore-size Distribution CT, ultrasonics
Contact Angle Tensiometer
2/4/2012
Application: Holistic Simulation of Climate Effects on Pavement
Ohio Instrumented Road: air temperature, precipitation; initial and final temperature, material properties of different layers; monitored temperature and water content by sensors
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
Simulated:
Dec 3
Dec 11
Dec 22
Volu
metr
ic M
ois
ture
conte
nt
Depth (m)
Measured:
Dec 3
Dec 11
Dec 22
0 1 2 3 4 5 6 7 8 9 10-6
-4
-2
0
2
4
6
8
10
12
14
16
18
Simulated:
S1
S3
S5
AirT
Te
mp
era
ture
(d
eg
C)
Time (day)
Measured:
S1
S3
S5
0 5 10 15 20 25 3020.20
20.24
20.28
20.32
20.36
20.40
Vert
ica
l str
ess (
MP
a)
Time (day)0 5 10 15 20 25 30
35
40
45
50
55
60
65
Ve
rtic
al str
ess (
MP
a)
Time (day)0 5 10 15 20 25 30
2
3
4
5
6
7
8
Ve
rtic
al str
ess (
MP
a)
Time (day)
Application: Frost Effects on Pipe Fracture
Max vertical stress VS time
Frost front reach the crown of the pipe
Arch
Case I Case II Case III
Case I Case II Case III
(cont.)
Sinusoidal
1 hour
0 3 6 9 12 15 18 21 24 27 302.8x107
3.0x107
3.2x107
3.4x107
3.6x107
3.8x107
4.0x107
Maxim
um
tensile
str
ess (
Pa)
Time (day)
Seasonly frost (upper)
Unfrozen (lower)
Permafrostd e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
d e m o d e m o d e m o d e m o d e m o
0 0.5 1 1.5 2
x 1010
0
5
10
15
20
25
30
35
Number of stress cycle
Depth
of cra
ck (
mm
)
Permafrost
Seasonal frost
Unfrozen
Service life decreases
0 4 8 12 16 200.0
0.2
0.4
0.6
0.8
1.0
Satu
ration
Distance from bottom (m)
HydrateResSim
MH21
STARSOIL
STARSSOLID
STOMPHYD
UNIVHOSTON
NewModel
0 4 8 12 16 200.2
0.3
0.4
0.5
0.6
0.7
0.8
Sa
tura
tio
n
Distance from bottom (m)
HydrateResSim
MH21
STARSOIL
STARSSOLID
STOMPHYD
UNIVHouston
NewModel
Application: Methane Hydrate Exploration and Geohazards
1 Day 100 Day
Bottom Top
20 m
NETL Gas Hydrate Simulation Comparison Program: Problem 1
0 10 20 30 40 50 60 70 80 90 100-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Su
bsid
en
ce
(m
)
Time (day)
Subsidence
Liu and Yu 2012
Summary
Multiphysics process in soils
An emerging frontier in soil mechanics
A “unified” theory might be possible
Improving engineering design could result from understanding and
simulating the fundamentals
We are continuing to explore into the fundamentals as well as many
exciting applications
It is a team effort
Acknowledgements
Funding Agencies
National Science Foundation, The Ohio Department of Transportation/FHWA, TRB, Minnesota
Department of Transportation, Cleveland Water Department, Industry sponsors (GRL/PDI, WPC
Inc., Durham Geo Enterprises, MWH Inc., DLZ Ohio Inc., etc)
Graduate Students
Past: Xinbao Yu (UT Arlington), Bin Zhang (Mike Baker), Yan Liu (GRL)
Current: Zhen Liu, Junliang Tao, Ye Sun, Chih-Chien Kung, Guangxi Wu, Jianying Hu, Quan
Gao
Undergraduate Researchers
Pete Simko, John Holman, Yuan Gao, Andrew Bittleman, Pete Simko, Cassandra McFadden,
Paul Mangola, Jingsi Lang, Donald Cartwright, Alex Potter-weight, Randall Beck, Vanessa
Penner,Peter Frank, Ben Ma, Rebecca Ciciretti, Joseph Brenner, Javanni Gonzalez, Vanessa
Penner, Grant Mott, et al.)
Department engineer Jim Berrila
Thank you