Induced Partial Saturation (IPS) Through Transport and Reactivity for Liquefaction Mitigation
Grant Number: CMMI-1134940
CMMI- Network for Earthquake Engineering Simulation Research (NEESR)
PIs: M. K. Yegian, A. N. Alshawabkeh, A. Farid, K. H. Stokoe, S. Thevanayagam
G d
Graduate
SStudents:
d
SSeda
d G
Gokyer,
k
Fritz
F i Nababan,
N b b
Ata
A Fi
Firat Karamanli
K
li
Motivation and Objective
Motivation of the project:
•To prevent liquefaction failure in saturated sands during earthquakes both for new sites and
for sites with existing structures.
Objective
j
off the pproject:
j
•Investigate application of a new liquefaction mitigation technique called “ Induced Partial
Saturation (IPS)” in which gas bubbles are generated in the field through transport and
reactivity of dissolved sodium percarbonate.
Constitutive Model
Effect of compressibility
of p
pore fluid
Contact stresses
between sand
particles, '0
  br
t
Air-Entrapped
Sand
Gas Entrapped
Sand
Fully Saturated
SaturatedSand
Sand
Building Response on Fully
Saturated Liquefied Sand
Air-Entrapped
Gas Entrapped
Building Response on IPS
Treated Sand
ρ
Schematic of the IPS application under an
existing structure
Auger
g Bits
Portable-Rig
SPT Rods
The rate of decomposition of sodium percarbonate relates to the rate of bubble
formation over time as a function of sodium percarbonate concentration, U
The density of solution as a linear function of sodium percarbonate concentration, U
Portable Geo-Rig Operation during
SPT Testing and Sampling
SPT Sample
IPS delivery system in the field
IPS Delivery system is used to introduce sodium percarbonate solution into the ground with
controlled pressure and controlled concentration of solution.
Numerical simulation of the constitutive model
Sketch of IPS Delivery System
Typical result of field scale simulation
Mixing tank
Zone of partial saturation ~ 10 m
• Finite element simulation of constitutive
model was created by modifying SUTRA
code created by USGS.
Saturation
15 m
Powder releasing
system
Mixer
2 m deep injection well
0.05 m
Fully
saturated
zone
• Modified code SUTRA-Bubble simulates
transport and reactivity of solution which
generates gas bubbles in 2-D and 3-D.
15 m
Set up for injection
of sodium
percarbonate
solution with
controlled pressure
Set up for mixing the
sodium percarbonate
with water for
controlled
concentration
Storage tanks
Pressure
controlled pump
Digital
Flowmeter
Strainer
Gas release
tube
Pressure
Gage
Injection system
Water resource
Strainer
Degree of saturation 5 hours after injection
Laboratory Experiments
Determination of Rate of Sodium Percarbonate reaction
U/U 0
Schematic of the IPS application in free
field
k r =(S
( bw ) 
Relative permeability of soil
kr The relative permeability of soil as a function of degree of saturation of soil, Sw
IPS through transport and reactivity in the field
Injection and transport of dissolved sodium percarbonate in the field
Effect of Darcy
Flow
Density of Sodium Percarbonate solution
Induced Partial Saturation (IPS)
Fully Saturated
Effect of variable Effect of fluid
displacement
p
due to
densityy
bubble generation
Rate of Sodium Percarbonate reaction
u = '0
then liquefaction occurs
ru = u/'0 = 1
Advantages of IPS:
• cost effective
• applicable to new sites
and sites with existing
structures
SPT Hammer140 lb
Constitutive Elements of the Model
Excess pore water pressure ratio, ru = u/'0
When
Generator
2
Sw ρ Sop  ερSbw 
Excess pore
water
pressure, u
pressure
Failures due to liquefaction during various
earthquakes
Portable Geo-Rig is used for :
• Borehole drilling
• SPT testing and sampling
• Driving
D i i injection
i j i tubes
b iinto the
h ground
d
• Driving IPS Cone
 k k r ρ 

 S wu S wu (1  S bw )   P
 S b   br
ρ U

 εS w
 RTερS uw  w 
  

 .   p-ρg    Q p
Pb
U t
 P
  t
 Pb  t
 μ 

What is liquefaction?
Soil becomes like liquid
during the earthquake
Portable Geo-Rig
Governing equation
Liquefaction Due to Earthquake
Liquefaction induced damages
Progress in research - FIELD
Progress in research - LABORATORY
• A constitutive model is created to solve the transport and reactivity of sodium
percarbonate solution, which generates gas bubbles.
•The model accommodates the change in saturation and permeability of soil due to gas
generation.
g the required
q
injection
j
pressure
p
and concentration of solution
• The model is used to design
for IPS delivery process in the field.
1.00
0.90
0
90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
Percarbonate C=0.20%
Percarbonate C=0.30%
U/U0
Department of Civil and
Environmental Engineering
Percarbonate C=0.40%
Percarbonate C=0.50%
0
40
80
120
160
200
240
1.00
0.90
0
90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
Percarbonate C=0.20%
Percarbonate C=0.30%
Percarbonate C=0.40%
Percarbonate C=0.50%
0
1
Time, hrs
2
3
4
5
• Total duration of reaction is
about 250 hours.
• The rate of reaction is slow
enough to prepare the
solution and inject into
ground and transport.
IPS cone for verification of IPS in the field
• IPS cone measures excess pore pressures generated when driven in the soil.
• Reduction in excess pore pressure generation from pre IPS to post IPS treated soil is an
indication of partial saturation level.
IPS Cone
Time, hrs
Cone Tip
Verification of Constitutive Model
Sketch of Model Verification Test Set up
Mariotte Bottle
For Constant Pressure
Generation of oxygen bubbles with reactivity of sodium percarbonate
with water
Suction to saturate
SPC
Solution
50 cm
2Na2CO3.3H2O2
4Na+ + 2CO32- + 3H2O2
3H2O2
3H2O +1.5 O2
Bubbles
• the constitutive model
Two way
valve
Scale
Sodium percarbonate – 2Na2CO3.3H2O2
Sodium percarbonate in water
Fully
Saturated
Sand
Hole for
collecting water
Water
basin
Injection
holes
Sealed
Sodium percarbonate
Sintered Metal
Experiments planned to verify:
91.41 cm
Holes for sampling
solution for
concentration
12.7 cm
• SUTRA-Bubble numerical
simulation
AW rod Coupler
IPS Cone driven with
Portable Geo-Rig
Acknowledgements
• David Whelpley - Director of College Facilities
• Michael Macneil - Laboratory Technician
• Kurt Braun – Machinist
• Caitlin Candee, Olivia Deterling, Amy
Javazewski, Kelsey Dunn–Undergraduate REU
students
• Aliza Holstein, Olivia Chung – NSF/YSP
• Dr. Ece Eseller-Bayat- former PhD student
• NSF/NEESR Award # : CMMI-1134940
Project Title: “Induced Partial Saturation (IPS)
Through Transport and Reactivity for Liquefaction
Mitigation”