1/2
9/2
01
81
ha
yw
ard
ba
ke
r.co
m
Gro
un
d Im
pro
vem
en
t for L
iqu
efa
ctio
n
Mitig
atio
nK
en
Kn
iss, P
.E.
En
gin
ee
r –N
orth
ern
Re
gio
n
2 •W
hat is
liqu
efa
ctio
n?
•E
va
lua
tion
me
tho
ds
•L
iqu
efa
ctio
n-b
ased
ha
za
rds
−Late
ral s
pre
adin
g
−B
earin
g c
apacity
−S
ettle
ment
•M
itiga
tion m
eth
od
s
−D
ensific
atio
n
−R
ein
forc
em
ent
−D
rain
age
•S
pe
cific
atio
ns fo
r Gro
un
d Im
pro
ve
me
nt
Pre
sen
tatio
n S
um
mary
1/2
9/2
01
82
3 Liq
ue
fac
tion
•T
he tra
nsfo
rmatio
n o
f a g
ranula
r mate
rial fro
m a
solid
to a
liquefie
d s
tate
as a
consequence o
f
incre
ased p
ore
-wate
r pre
ssure
and re
duced
effe
ctiv
e s
tress (M
arc
uson
1978)
−F
rom
Su
mm
ary
Re
po
rt from
the
19
96
an
d 1
99
8 N
CE
ER
/NS
F W
ork
sh
ops o
n
Eva
lua
tion o
f Liq
uefa
ctio
n R
esis
tan
ce o
f Soils
4
05
10
15
20
25
Sh
ear s
tress c
ycle
s
0
0.2
0.4
0.6
0.8 1
Pore pressure ratio
So
il wa
nts
to g
et to
this
sta
te.
Bu
t wa
ter c
an
no
t mo
ve
. So
po
re p
ressu
re in
cre
ase
s
∆u
>0
•In
cre
ase
d p
ore
pre
ssu
re m
ea
ns
low
er e
ffectiv
e s
tress
•If R
u =1
, the
n σ
’ = 0
•If σ
’ = 0
, limite
d s
tren
gth
an
d
hig
h c
om
pre
ssib
ility
Po
re p
ressu
re ra
tio (R
u ) = ra
tio o
f exce
ss
po
re p
ressu
re to
initia
l effe
ctiv
e s
tress
Liq
ue
fac
tion
(Ru)
���
��
���
1/2
9/2
01
83
5 Liq
ue
fac
tion
-rela
ted
Ha
za
rds
Be
arin
g
Ca
pa
city
Diffe
ren
tial
Se
ttlem
en
t
La
tera
l Sp
rea
din
g
6
�L
iqu
efa
ctio
n P
ote
ntia
l is a
fun
ctio
n o
f:
�S
oil T
yp
e, R
ela
tive
De
nsity, In
itial
Co
nfin
ing
Pre
ssu
re
�In
ten
sity
an
d D
ura
tion
of G
rou
nd
Sh
akin
g
�C
om
mo
n In
pu
t Pa
ram
ete
rs:
�P
ea
k G
rou
nd
Acce
lera
tion
(PG
A)
�M
ag
nitu
de
(M)
Liq
ue
fac
tion
1/2
9/2
01
84
7 �N
atio
na
l Ce
nte
r for E
arth
qu
ake
En
gin
ee
ring
Re
se
arc
h (N
CE
ER
)
Su
mm
ary
Re
po
rt (19
97
Me
etin
g, p
ub
lish
ed
in J
GG
E, 2
00
1).
�S
ee
d a
nd
Idris
s(1
97
1):
�N
orm
aliz
ed
by v
ertic
al e
ffectiv
e s
tress, C
yclic
Stre
ss R
atio
(CS
R):
�M
ea
su
res s
eis
mic
de
ma
nd
on
a s
oil la
ye
r
Liq
ue
fac
tion
-C
SR
dvo
cyclicr
g
aσ
τm
ax6
5.
0=
d
vo voeq
rg
aCSR
'
max
65
.0
σ σ=
8 �D
efin
e th
e S
ite S
eis
mic
Pa
ram
ete
rs:
�P
ea
k G
rou
nd
Acce
lera
tion
, PG
Ao
r amax :
Liq
ue
fac
tion
-C
SR
d
vo voeq
rg
aCSR
'
max
65
.0
σ σ=
Ma
ps
So
ftwa
re/a
pplic
atio
ns
1/2
9/2
01
85
9 �D
efin
e th
e S
ite S
eis
mic
Pa
ram
ete
rs:
�S
he
ar s
tress re
du
ctio
n fa
cto
r, rd :
Liq
ue
fac
tion
-C
SR
d
vo voeq
rg
aCSR
'
max
65
.0
σ σ=
Use
co
nsis
ten
t de
sig
n
me
tho
d w
he
n s
ele
ctin
g r
d
an
d lo
okin
g a
t liqu
efa
ctio
n
trigg
erin
g
10
�C
ap
acity
of s
oil to
resis
t liqu
efa
ctio
n:
�C
yclic
Re
sis
tan
ce
Ra
tio (C
RR
)
�O
lde
r pu
blic
atio
ns h
ave
CS
Rfie
ld , CS
Rl, C
SR
L, C
SR
L
�F
un
ctio
n o
f:
�G
eo
log
ic H
isto
ry (d
ep
osit ty
pe
, ag
ing
)
�S
oil s
tructu
re a
nd
co
nte
nt (re
lativ
e d
en
sity, fin
es c
on
ten
t, cla
y
co
nte
nt)
�G
rou
nd
wa
ter e
leva
tion
�D
eve
lop
ed
from
ca
se
his
torie
s (e
mp
irica
l)
Liq
ue
fac
tion
-C
RR
1/2
9/2
01
86
11
�C
ap
acity
of s
oil to
resis
t liqu
efa
ctio
n:
�C
yclic
Re
sis
tan
ce
Ra
tio (C
RR
)
�U
se
d to
me
asu
re s
usce
ptib
ility to
liqu
efa
ctio
n
�E
xp
resse
d a
s fa
cto
r of s
afe
ty: F
S=
CR
R/C
SR
�L
iqu
efa
ctio
n P
ote
ntia
l Ind
ex: L
PI =
f(FS
,z,T
)
�H
ow
ca
n w
e u
se
this
info
rma
tion
?
�C
on
se
qu
en
ce
ba
se
d d
esig
n
�C
alc
ula
te d
yn
am
ic s
ettle
me
nt, b
ea
ring
ca
pa
city
an
d la
tera
l sp
rea
din
g
Liq
ue
fac
tion
-C
RR
12 Liq
ue
fac
tion
-C
RR
SP
T
CP
T
Sh
ea
r wa
ve
ve
locity
Ba
se
line fo
r CR
R c
urv
es is
ma
gn
itud
e 7
.5 e
arth
qu
ake
��� .��0.65����
�
���
���
��
���
1/2
9/2
01
87
13 Liq
uefa
ctio
n –
Mag
nitu
de S
calin
g F
acto
r (MS
F)
MS
F is
no
rma
lize
d to
ma
gn
itud
e 7
.5 e
arth
qu
ake
MS
F is
use
d to
co
rrect th
e
CR
R c
urv
es b
ase
d o
n
ma
gn
itud
e o
f the
ea
rthq
ua
ke
14
Exam
ple
•S
eis
mic
P
ara
me
ters
:−
20
0 C
olle
ge A
ve
Me
dfo
rd, M
A
−L
atitu
de
: 4
2.4
06
03
2499
999
99
−L
on
gitu
de:
-71
.11
68
83
6
−P
GA
: 0.1
66
−R
etu
rn P
erio
d: 2
47
5
−M
ea
n (R
,M,e
0) =
30
.99
km
, 5.5
6, -.0
1σ
1/2
9/2
01
88
15
•L
oo
se
Sa
nd
−A
ssu
me γ
= 1
20
pcf
−(N
1 )60 a
t 20
’ de
pth
= 1
0 b
pf
−F
ine
s C
on
ten
t < 5
% (S
W/S
P)
−W
ate
r tab
le d
urin
g e
arth
qu
ake @
10
’ d
ep
th
•In
pu
t Pa
ram
ete
rs:
−σ
vo ’=
1776 p
sf
−σ
vo =
2400 p
sf
−rd
= 0
.95
−P
GA
=0.1
66g
−M
=5.5
6
−M
SF
= 1
.76
Ex
am
ple
CS
RM
7.5
= 0
.13
9
��� .��0.65����
�
���
��� ��
��� .��0.650.166
2400
1776
0.95
CR
R =
0.1
1
!"�#$$∗&"!
#"$&'.(
�).**∗*.'+
).*,-
FS
=1
.39
16
Liq
ue
fac
tion
pe
r Ma
ss
ac
hu
se
ttes
Bu
ildin
g C
od
e
•A
ssu
mptio
ns:
−S
s =0
.35
an
d F
a =1
.52
−S
ite C
lass D
−M
SF
= 1
.76
(low
er b
ou
nd
for M
=6
)
−F
S=
1.1
•E
va
lua
te p
oin
t at d
ep
th o
f 20
ft with
GW
T a
t
de
pth
of 1
0 ft a
nd
Nfie
ld = 6
bp
f
•B
ack-c
alc
ula
te P
GA
usin
g N
CE
ER
pro
ced
ure
−N
1(6
0) =
8.5
bp
f
−C
RR
= 0
.09
(Fro
m C
RR
cu
rve
s)
−P
GA
= 0
.17
g
X
Da
ta p
oin
t from
exa
mp
le p
rob
lem
1/2
9/2
01
89
17 Liq
ue
fac
tion
•C
an
use
co
mm
erc
ial o
r
cu
sto
m s
oftw
are
18
•C
yclic
so
ften
ing
or s
tren
gth
loss –
no
t true
liqu
efa
ctio
n
Co
he
siv
e M
ate
rials
Se
ed
et a
l., 20
03
Bra
y &
Sa
ncio
, 20
06
1/2
9/2
01
8
10
19 •
Wh
at is
liqu
efa
ctio
n?
•E
va
lua
tion
me
tho
ds
•L
iqu
efa
ctio
n-b
ase
d h
aza
rds
−B
ea
ring
ca
pa
city
−L
ate
ral s
pre
ad
ing
−S
ettle
me
nt
•M
itiga
tion
me
tho
ds
−D
en
sific
atio
n
−R
ein
forc
em
en
t
−D
rain
ag
e
Pre
sen
tatio
n S
um
mary
20 •
Ze
ro e
ffectiv
e s
tress →
Lo
w fric
tion
al s
tren
gth
−S
tren
gth
ma
y b
e v
ery
sm
all, b
ut z
ero
−U
se
resid
ua
l un
dra
ine
d s
he
ar s
tren
gth
to e
va
lua
te b
ea
ring
ca
pa
city
Liq
uefa
ctio
n-b
ased
Hazard
s –
Stre
ng
th L
oss
30
0 p
sf
Sta
rk a
nd
Me
sri, 1
99
2
16
0 p
sf
1/2
9/2
01
8
11
21 •
Re
du
ce
d s
oil s
tren
gth
•A
dd
ition
al la
tera
l loa
din
g
•M
eth
od
s o
f eva
lua
tion
:
−E
mp
irica
l (Yo
ud
, 20
02
, oth
ers
)
−P
se
ud
o-s
tatic
limit e
qu
ilibriu
m w
ith re
sid
ua
l sh
ea
r stre
ng
th v
alu
es
−In
teg
ratio
n o
f sh
ea
r stra
ins d
urin
g e
ve
nt
(La
tera
l dis
pla
ce
me
nt in
de
x) (Z
ha
ng
, et a
l., 2
00
4, C
etin
, 20
09
)
−S
ite s
pe
cific
nu
me
rica
l an
aly
se
s (F
LA
C,
Pla
xis
, oth
ers
)
Liq
ue
fac
tion
-ba
se
d H
aza
rds
–L
ate
ral S
pre
ad
ing
an
d
Flo
w S
lidin
g
Fro
m Id
riss
an
d B
ou
lan
ge
r, 20
08
22
Liq
uefa
ctio
n-b
ased
Hazard
s –
Settle
men
t
To
kim
ats
ua
nd
Se
ed
, 19
87
Ish
iha
ra a
nd
Yo
sh
imin
e, 1
99
2
Zh
an
g e
t al., 2
00
2
CS
R
1/2
9/2
01
8
12
23
•C
on
se
qu
en
ce
ba
se
d a
pp
roa
ch
•S
tart a
co
nve
rsa
tion
with
yo
ur o
wn
er, d
esig
n te
am
an
d s
pe
cia
lty c
on
tracto
r
−C
on
tracto
rs a
re g
en
era
lly h
ap
py to
he
lp w
ith in
itial re
vie
w a
nd
ord
er o
f
ma
gn
itud
e p
ricin
g
Pro
ject D
evelo
pm
en
t
Feasib
ility A
ssessm
en
t an
d B
ud
get
24
•D
iscu
ssio
n in
ge
ote
ch
nic
al e
ng
ine
erin
g re
po
rt an
d s
pe
cific
atio
n w
ith s
ite s
pe
cific
co
nd
ition
s
−H
ow
did
yo
u d
ete
rmin
e C
SR
with
no
imp
rove
me
nt?
�M
ag
nitu
de
�P
GA
�D
esig
n G
rou
nd
Wate
r Ta
ble
�E
va
lua
tion
Me
tho
d
•A
ttach
ca
lcu
latio
ns in
ap
pe
nd
ix
Pro
ject D
evelo
pm
en
t
Bid
Do
cu
men
ts fo
r Gro
un
d Im
pro
vem
en
t
1/2
9/2
01
8
13
25
•S
oil b
orin
gs w
ith la
bo
rato
ry d
ata
−G
rain
siz
e d
istrib
utio
n
−A
tterb
erg
limits
−C
lay v
s s
ilt co
nte
nt
•C
PT
so
un
din
gs w
ith ra
w d
ata
Pro
ject D
evelo
pm
en
t
Bid
Do
cu
men
ts fo
r Gro
un
d Im
pro
vem
en
t
26
•Ta
ilor v
erific
atio
n te
stin
g a
nd
acce
pta
nce
to d
esire
d m
ea
ns o
f
imp
rove
me
nt
•P
rovid
e d
yn
am
ic s
ettle
me
nt
tole
ran
ce
or m
inim
um
facto
r of
sa
fety
Pro
ject D
evelo
pm
en
t
Sp
ecific
atio
ns
1/2
9/2
01
8
14
27
•B
e c
on
sis
ten
t with
de
sig
n m
eth
od
olo
gy a
nd
be
cle
ar w
ha
t me
tho
do
log
ies a
re a
pp
rop
riate
or n
ot
ap
pro
pria
te
•F
ine
s c
on
ten
t ca
n e
ffect N
-va
lue
s a
nd
tip
resis
tan
ce
. Th
e m
inim
um
N-v
alu
e in
cle
an
sa
nd
will lik
ely
co
rrela
te w
ith a
low
er N
-va
lue
in s
an
dy
silt.
Pro
ject D
evelo
pm
en
t
Sp
ecific
atio
ns
28 •
Wh
at is
liqu
efa
ctio
n?
•E
va
lua
tion
me
tho
ds
•L
iqu
efa
ctio
n-b
ase
d h
aza
rds
−L
ate
ral s
pre
ad
ing
−B
ea
ring
ca
pa
city
−S
ettle
me
nt
•M
itiga
tion
me
tho
ds
−D
en
sific
atio
n
−R
ein
forc
em
en
t
−D
rain
ag
e
Pre
sen
tatio
n S
um
mary
1/2
9/2
01
8
15
29
•In
cre
ase
stre
ng
th (↑
CR
R)
−D
en
sify
So
il
−C
em
en
tatio
n
•D
ecre
ase
driv
ing
stre
ss(↓
CS
R)
−S
he
ar re
info
rce
me
nt w
ithin
so
il ma
ss
•R
ed
uce
po
re p
ressu
re b
uild
up
Liq
uefa
ctio
n M
itigatio
n
Causes
Consequences
•D
esig
n th
e s
tructu
re fo
r
liqu
efa
ctio
n:
−G
rad
e b
ea
ms, m
ats
−In
cre
ase
d s
tructu
ral re
du
nd
an
cy a
nd
stre
ng
th
•B
yp
ass th
e liq
ue
fiab
le s
oil:
−D
ee
p fo
un
da
tion
s
•R
ed
uce
liqu
efa
ctio
n-in
du
ce
d
se
ttlem
en
t
30
Liq
uefa
ctio
n M
itigatio
n
1/2
9/2
01
8
16
31
•In
cre
ase
stre
ng
th (↑
CR
R) b
y
incre
asin
g re
lativ
e d
en
sity
of
sa
nd
s
•A
dva
nta
ge
s:
−F
ield
ve
rifiab
le
−U
se
d o
ve
r 50
ye
ars
, thro
ug
h m
an
y la
rge
ea
rthq
ua
ke
s
−S
eve
ral p
ee
r-revie
we
d d
ocu
me
nts
�W
ell a
cce
pte
d w
ithin
ind
ustry
Liq
uefa
ctio
n M
itigatio
n -
Den
sific
atio
n
32
•M
eth
ods:
−D
yn
am
ic c
om
pa
ctio
n
−V
ibro
-co
mp
actio
n
−V
ibro
-rep
lace
me
nt
−C
om
pa
ctio
n g
rou
ting
−B
last d
en
sific
atio
n
Liq
uefa
ctio
n M
itigatio
n -
Den
sific
atio
n
1/2
9/2
01
8
17
33 D
yn
am
ic C
om
pactio
n
Dyn
am
ic D
ee
p C
om
pa
ctio
n
•D
rop
larg
e m
ass to
gro
un
d s
urfa
ce
to
de
nsify
so
ils.
•T
yp
ica
l ma
ss ~
10
-30
To
ns
•T
yp
ica
l dro
p h
eig
ht 5
0-1
00
ft
•G
rid s
pa
cin
g o
f 7 ft
x7
ftto
20
ftx2
0 ft
Ra
pid
Imp
ac
t Co
mp
ac
tion
•U
se
hyd
rau
lic p
ile h
am
me
r to d
rop
we
igh
t
on
to s
tee
l pla
te
•T
yp
ica
l ma
ss ~
8 T
on
s
•T
yp
ica
l dro
p h
eig
ht ~
3 ft
•T
yp
ica
l sp
acin
g ~
7 ft
grid
<1
0 ft
<2
5 ft
34 Vib
ro-c
om
pactio
n a
nd
Vib
ro-re
pla
cem
en
t
1/2
9/2
01
8
18
35
Vib
ro S
yste
ms
Vib
ro C
om
pactio
n -
Densific
atio
n o
f gra
nula
r soils
Vib
ro P
iers
-R
ein
forc
em
ent w
ith a
stiff c
olu
mn o
f com
pacte
d a
ggre
gate
. Genera
lly <
20’ d
eep a
nd p
erfo
rmed
by p
redrillin
g a
hole
in s
oils
in w
hic
h th
e h
ole
will s
tay
open. V
P w
ill als
o d
ensify
gra
nula
r soils
if pre
sent.
Vib
ro R
ep
lacem
en
t–
Rein
forc
em
ent o
f fine g
rain
ed s
oils
and d
ensific
atio
n o
f gra
nula
r soils
with
a s
tiff colu
mn o
f com
pacte
d a
ggre
gate
DensificationReinforcement
36 D
en
sific
atio
n –
Vib
roS
yste
ms -
Exam
ple
�L
oo
se s
and z
on
e
�H
osp
ital s
ite
�V
ibro
-
rep
lace
me
nt
to 4
5 ft.
1/2
9/2
01
8
19
37 V
ibro
Eq
uip
men
t
38
•S
tiff gro
ut m
ix:
−S
an
d, c
em
en
t, wa
ter,
filler
•F
orm
gro
ut ‘b
ulb
s’
to d
ispla
ce a
nd
com
pact s
oil
Den
sific
atio
n –
Co
mp
actio
n G
rou
ting
1/2
9/2
01
8
20
39 D
en
sific
atio
n –
Co
mp
actio
n G
rou
ting
�S
an
dy s
ite
�C
om
pa
ctio
n
gro
utin
g fo
r
liqu
efa
ctio
n
mitig
atio
n
�U
rba
n s
ite, n
o
vib
ratio
ns
40 C
om
pactio
n G
rou
ting
–In
sta
lling
Pip
e
Sm
all
Ve
ry L
arg
e
1/2
9/2
01
8
21
41
•In
cre
ase
stre
ng
th (↑
CR
R)
−D
en
sify
So
il
−C
em
en
tatio
n
•D
ecre
ase
driv
ing
stre
ss(↓
CS
R)
−S
he
ar re
info
rce
me
nt w
ithin
so
il ma
ss
•R
ed
uce
po
re p
ressu
re b
uild
up
Liq
uefa
ctio
n M
itigatio
n
Causes
Consequences
•D
esig
n th
e s
tructu
re fo
r
liqu
efa
ctio
n:
−G
rad
e b
ea
ms, m
ats
−In
cre
ase
d s
tructu
ral re
du
nd
an
cy a
nd
stre
ng
th
•B
yp
ass th
e liq
ue
fiab
le s
oil:
−D
ee
p fo
un
da
tion
s
•R
ed
uce
liqu
efa
ctio
n-in
du
ce
d
se
ttlem
en
t
42
•R
ed
uce
cyclic
sh
ea
r
stre
ss/s
train
by in
sta
lling
‘stiffe
r’ ele
me
nts
•A
pp
lica
tion
s:
−N
on
-de
nsifia
ble
so
ils (s
ilty s
an
ds,
silts
)
−L
arg
e m
ag
nitu
de
ea
rthq
ua
ke
s
•N
ot v
erifia
ble
by fie
ld te
stin
g
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t
τsoil
τsoil
τinc
1/2
9/2
01
8
22
43
•L
arg
e m
ag
nitu
de
ea
rthq
ua
ke
s:
−P
GA
~0
.3-1
.0g
−M
>7
•Typ
ica
l CS
R v
alu
es ~
0.3
-0.6
•H
igh
liqu
efa
ctio
n p
ote
ntia
l for
all s
oils
N<
30
−D
en
sific
atio
n h
as lim
ited
ap
plic
atio
n
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t
Re
achin
g th
is z
on
e is
ha
rd
44
•O
rigin
al D
esig
n M
eth
odolo
gy
�S
hear s
tress re
ductio
n fa
cto
r (KG) (B
aez a
nd
Martin
, 1993):
GIN
C=
Inclu
sio
n s
hear m
odulu
s
GS
oil =
Soil s
hear m
odulu
s
AR
R=
Ain
clu
sio
n /Ato
tal
�S
train
com
patib
ility a
nd fo
rce e
quilib
rium
�A
ssum
es lin
ear e
lastic
behavio
r
�C
SR
applie
dto
soil =
KG
* CS
Rearth
quake
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
tτsoil
τsoil
τinc
−+
=1
1
1
Soil
INC
G
G GARR
K
1/2
9/2
01
8
23
45
•10%
Are
a
Repla
cem
ent
•G
INC/G
SO
IL =5
•K
G=
0.7
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t0
0.5
CS
R an
d C
RR
60
50
40
30
20
10 0
Depth [ft]
CS
R P
re
CS
R P
ost
CR
R P
re
04
08
01
20
16
020
0q
t [tsf]
60
50
40
30
20
10 0
Depth [ft]
CP
T-9
00
.40
.81.2
1.6
2R
f [%]
60
50
40
30
20
10 0
Depth [ft]
00
.51
1.5
2F
acto
r of S
afety
60
50
40
30
20
10 0
Depth [ft]
−+
=1
1
1
Soil
INC
G
G GARR
K
46
•L
imita
tions o
f Ba
ez a
nd
M
artin
:
−L
ine
ar e
lastic
be
ha
vio
r
−S
he
ar s
train
ing o
nly
-n
o b
en
din
g
−S
train
co
mp
atib
ility –
no
‘flo
w’ o
r rela
tive
slip
pin
g
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t
−+
=1
1
1
Soil
INC
G
G GARR
K
Wh
at h
ap
pe
ns in
extre
me
ca
se
s?
•W
hat a
bo
ut a
ste
el p
ile?
−G
INC/G
soil ~
25
00
−N
ee
d K
G=
0.8
?
−W
e c
an
driv
e W
14x1
20
pile
s o
n 5
0’ s
pa
cin
gs
•W
hat a
bo
ut a
ste
el p
ile?
−G
INC/G
soil ~
25
00
−N
ee
d K
G=
0.8
?
−W
e c
an
driv
e W
14x1
20
pile
s o
n 5
0’ s
pa
cin
gs
1/2
9/2
01
8
24
47
•R
ecent re
searc
h a
t UC
Davis
, Ore
gon S
tate
, and U
C S
an D
iego
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t
Nu
me
rical A
na
lysis
−+
=1
1
1
Soil
INC
G
G GARR
K
Raya
majh
i, et a
l., AS
CE
Geo-
Congre
ss 2
012
48
Liq
uefa
ctio
n M
itigatio
n –
Rein
forc
em
en
t Pan
els
1/2
9/2
01
8
25
49
•R
ecent re
searc
h a
t UC
Davis
, Ore
gon S
tate
, and U
C S
an D
iego
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t
Nguye
n, e
t al., A
SC
E G
eo-
Congre
ss 2
012
Gr =
13
.5G
r = 5
0
50
•C
om
pa
re R
rdfo
r sin
gle
ele
me
nt v
s p
an
el c
on
figu
ratio
n
Liq
uefa
ctio
n M
itigatio
n -
Rein
forc
em
en
t
Nguye
n, e
t al., A
SC
E G
eo-
Congre
ss 2
012
Gr =
13
.5G
r = 5
0N
um
eric
al A
na
lysis
−+
=1
1
1
Soil
INC
G
G GARR
K
Raya
majh
i, et a
l., AS
CE
Geo-
Congre
ss 2
012
1/2
9/2
01
8
26
51
Liq
uefa
ctio
n M
itigatio
n –
Rein
forc
em
en
t Pan
els
Cu
tter
so
il mix
er
(CS
M)
Mu
lti-
axis
mix
ing
Tre
nch
Mix
ing
(TR
D)
La
rge
Dia
me
ter
Sin
gle
Axis
52
Liq
uefa
ctio
n M
itigatio
n
Jo
rda
n H
igh
Sch
ool, L
on
g B
ea
ch
CA
Ve
ntu
ra C
an
cer
Ce
nte
r, CA
1/2
9/2
01
8
27
53
•In
cre
ase
stre
ng
th (↑
CR
R)
−D
en
sify
So
il
−C
em
en
tatio
n
•D
ecre
ase
driv
ing
stre
ss(↓
CS
R)
−S
he
ar re
info
rce
me
nt w
ithin
so
il ma
ss
•R
ed
uce
po
re p
ressu
re b
uild
up
Liq
uefa
ctio
n M
itigatio
n
Causes
Consequences
•D
esig
n th
e s
tructu
re fo
r
liqu
efa
ctio
n:
−G
rad
e b
ea
ms, m
ats
−In
cre
ase
d s
tructu
ral re
du
nd
an
cy a
nd
stre
ng
th
•B
yp
ass th
e liq
ue
fiab
le s
oil:
−D
ee
p fo
un
da
tion
s
•R
ed
uce
liqu
efa
ctio
n-in
du
ce
d
se
ttlem
en
t
54
•L
imit p
ore
pre
ssu
re b
uild
up
du
ring
ea
rthq
ua
ke
Liq
uefa
ctio
n M
itigatio
n-
Dra
inag
e
Liq
ue
factio
n
PP
dis
sip
ate
s
1/2
9/2
01
8
28
55
•E
arth
qu
ake
Dra
ins –
EQ
Dra
ins
−P
refa
bric
ate
d d
rain
s to
red
uce
dra
ina
ge
pa
th d
urin
g e
ve
nt
Liq
uefa
ctio
n M
itigatio
n-
Dra
inag
e
56
•B
ase
d o
n ra
dia
l co
nso
lida
tion
the
ory
Liq
uefa
ctio
n M
itigatio
n -
Dra
inag
e
∂ ∂−
∂ ∂=
∂ ∂⋅
∂ ∂t u
t um
r u
r
k
r
g
v
w h1
γ
∂ ∂−
∂ ∂=
∂ ∂∂ ∂
t u
t u
r u
rr
cg
h
1
wv
hhm
kc
γ=
=∂ ∂
=
= =∂ ∂
∂ ∂∂ ∂
=∂ ∂
2sin
2tan
testundrain
edin
on
liquefacti
cau
sing
cy
cles
stress
unifo
rm
of
Num
ber
7.0
~
arcsin2
2
'
2 1
'
u
u
dl eq
og
l
lo g
d eq gg
r r
tN N
N u
N
N Nu
t N
t N
t N
N u
t u
π π
θπ σ
θπ
σ
θ
θ
DeA
lba
et al., 19
75
Assu
me p
eriod
ic wav
e form
•C
ha
ng
e in
PP
pe
r cycle
de
pe
nds o
n P
P o
f
pre
vio
us c
ycle
•N
Lb
ase
d o
n C
SR
of s
oil,
SP
T, F
ine
s
•N
eq , td
are
fun
ctio
ns o
f
ea
rthq
uake
, bu
t the
re a
re
co
rrela
tions to
ma
gn
itude
Diffe
rentia
l Eq
ua
tion
s –
Lo
ts o
f the
m!
1/2
9/2
01
8
29
57
•F
acto
r of s
afe
ty a
ga
inst
liqu
efa
ctio
n is
the
inve
rse
of
the
po
re p
ressu
re ra
tio (∆
u/σ
ο ’)
•S
ettle
me
nt m
ust a
lso
be
ad
dre
sse
d:
Liq
uefa
ctio
n M
itigatio
n -
Dra
inag
e
()(
)()
()(
)() '
'
'
'vou
New
vlayer
layer
vou
v
vNew
vlayer
layer
Rm
T
Ru
u
mT
σδ
σσ
σδ
− −
=
=∆
∆=
∆
∆=
mv
un
ch
an
ge
d
mv
un
ch
an
ge
d
58
•G
rap
hic
al s
olu
tion
s to
diff e
qu
atio
n (J
GS
):
−A
ddre
ss d
rain
siz
e, w
ell re
sis
tance
−P
rovid
es R
u, b
ut n
o s
ettle
ment c
alc
ula
tions
•F
EQ
Dra
in–
Fin
ite E
lem
en
t so
ftwa
re p
rog
ram
−P
rovid
es R
u a
nd s
ettle
ment c
alc
ula
tions
•B
oth
meth
ods n
eed th
e fo
llow
ing:
−S
oil p
erm
eability, k
h
−S
oil c
om
pre
ssib
ility, mv ,
−E
arth
quake d
ura
tion, td
−N
um
ber o
f earth
quake c
ycle
s, N
eq
−D
rain
spacin
g (tria
l valu
es)
Liq
uefa
ctio
n M
itigatio
n -
Dra
inag
e
1/2
9/2
01
8
30
59
•Typ
ica
lly 3
-6 in
ch
es d
iam
ete
r
•S
lotte
d P
VC
pip
e w
ith filte
r fab
ric
•Typ
ica
l sp
acin
g 3
-6 ft tria
ng
ula
r
•In
sta
lled
with
larg
e s
tee
l pro
be
with
win
gs
(de
nsific
atio
n a
lso
inte
nd
ed
)
EQ
Dra
in D
eta
ils
60
EQ
Dra
in In
sta
llatio
n
1/2
9/2
01
8
31
61
•In
cre
ase
stre
ng
th (↑
CR
R)
−D
en
sify
So
il
−C
em
en
tatio
n
•D
ecre
ase
driv
ing
stre
ss(↓
CS
R)
−S
he
ar re
info
rce
me
nt w
ithin
so
il ma
ss
•R
ed
uce
po
re p
ressu
re b
uild
up
Liq
uefa
ctio
n M
itigatio
n
Causes
Consequences
•D
esig
n th
e s
tructu
re fo
r
liqu
efa
ctio
n:
−G
rad
e b
ea
ms, m
ats
−In
cre
ase
d s
tructu
ral re
du
nd
an
cy a
nd
stre
ng
th
•B
yp
ass th
e liq
ue
fiab
le s
oil:
−D
ee
p fo
un
da
tion
s
•R
ed
uce
liqu
efa
ctio
n-in
du
ce
d
se
ttlem
en
t
ha
yw
ard
ba
ke
r.co
m
Th
an
k Y
ou
! Qu
estio
ns?
