evaluation of sheet pile-ring countermeasure for oil tank site.pdf
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8/11/2019 Evaluation of Sheet Pile-Ring Countermeasure for oil tank site.pdf
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E L S E V I E R
Soil D ynamicsand Earthquake Engineering15 (1996) 369-379
Copyright 1996 Elsevier ScienceLimited
Printed in G rea t Britain. All fights reserved
P I I : S 0 2 6 7 - 72 61 (9 6) 00 0 1 5 -2 0267-7261/96/ 15.00
E v a l u a t i o n o f s h e e t p i l e r i n g c o u n t e r m e a s u r e
aga i n s t l i q u e fac t i on for o i l t an k s i t e
J in g zh e Z h en g K i ieh i S u zu k i N a o to O h b o
Civil Engineer ing Departme nt I Kafima Technical Ins t i tute 19-1 Tobitakyu 2-Chome Chofu-shi Tokyo 182 Japan
J . H. Prevost
De partm ent o f Civil Engineering and Operations Research Princeton University Princeton N J 08544 U SA
Received 11 Apr i l 1995; accepted 4 Apr i l 1996)
The evaluat ion of a countermeasure against l iquefact ion which uses a sheet p i le-
r ing for o i l tank s i tes is p resented . The s imulat ion of ear thquake responses
observed at ta nk s i tes with and witho ut sheet p i le- r ing is f ir s t per fo rme d to val idate
the three-d imension al f in i te e lem ent numer ical model . Using the num er ical model ,
l iquefact ion analysis is per form ed and the excess pore w ater pressure generated in
th e so il an d th e se t t l emen t o f t an k a r e in v est ig ated . Th e co m p ar i so n o f tw o - an d
three-d imensional models is a lso conducted to assess the applicabil i ty of two-
dimensional analysis . The resu lts show that the numer ical model could s imulate
th e o b se r v ed ea r th q u ak e r esp o nses o f t an k - r in g - so i l sy s tem, an d th a t th e excess
pore w ater pressure and the set t lement of the tank cou ld be s ign if ican tly reduced
using a sheet p i le- r ing . The two-dimensional analysis proves to be capable of
r ep r esen t in g th e m ain f ea tu r es o f th e d y n amic r esp o n se o f th e th r ee - d imen s io n a l
tan k - r in g - so i l sy s tem. Co p y r ig h t 1 9 9 6 E lsev ie r Scien ce L td
Key words: l iquefact ion , countermeasure, tank , ear thquake observat ion , f in i te
eleme nt analysis .
1 I N T R O D U C T I O N
T h e i n v e s t i g a t i o n o f t h e d a m a g e d u e t o e a r t h q u a k e s h a s
r e v e a l e d t h a t s o i l l i q u e f a c t io n m a y c a u s e s e v e re d a m a g e
t o o i l s t o r a g e t a n k s . 1 T h e r e f o r e d e v e l o p i n g c o u n t e r -
m e a s u r e s a g a i n s t l i q u e f a c t i o n h a s b e c o m e a n u r g e n t
t a s k .
S e v e ra l c o u n t e r m e a s u r e s a g a i n s t l i q u ef a c t io n f o r t a n k
s i te s h a v e b e e n p r o p o s e d b a s e d o n t h e l e s s o n s l e a r n t f r o m
p a s t e a r t h q u a k e d a m a g e . 2 T h e s e c o u n t e r m e a s u r e s m a y
b e c l a s s if i ed i n t o t h r e e t y p e s : ( 1 ) i m p r o v e t h e p r o p e r t i e s
o f f o u n d a t i o n s o i l, s u c h a s so i l d e n s i t y ; ( 2 ) h a s t e n t h e
d i s s i p a t i o n o f t he e x c e s s p o r e w a t e r p r e s s u r e ; a n d ( 3)
c o n s t r a i n t h e f o u n d a t i o n s o i l i n o r d e r t o r e d u c e t h e
s e i s m i c s h e a r s t r es s e s. O n e p r o m i s i n g m e t h o d o f t h e
t h i r d t y p e i s t h e s h e e t p i l e - ri n g c o u n t e r m e a s u r e p r o p o s e d
b y S a w a u c h i
et al . 3
w h i c h i s t o c o n s t r a i n t h e s o f t s o i l
u n d e r a t a n k b y a s h e e t p i l e - r i n g i n s e r t e d i n t o h a r d
u n d e r l y i n g s o i l .
369
B e f o r e a p p l y i n g t h i s c o u n t e r m e a s u r e t o p r a c t i c a l
t a n k s i te s , t h e d e g r e e t o w h i c h t h e u s e o f a s h e e t p il e -
r i n g c a n r e d u c e p o r e w a t e r p r e s s u r e a n d s e t t l e -
m e n t h a s t o b e c la r if i ed . U p t o n o w , h o w e v e r , t h e r e
h a v e b e e n v e r y f e w s t u d i e s p e r f o r m e d t o w a r d s t h i s
e n d .
S o i l l i q u e f a c t i o n i s o f t e n s i m u l a t e d b y n u m e r i c a l
a n a ly s is . Ia i a n d K a m e o k a h a v e p e r f o r m e d n u m e r i c a l
a n a l ys i s o f e a r t h q u a k e - i n d u c e d d a m a g e t o a n c h o r e d
s h e e t p i l e q u a y w a l l s . 4 T h e i r n u m e r i c a l r e s u l t s a r e
b a s i c a l l y c o n s i s t e n t w i t h th e o b s e r v e d p e r f o r m a n c e o f
t h e q u a y w a l ls . P o p e s c u a n d P r e v o s t h a v e r e p r e s e n t e d a
v a l i d a t i o n u s i n g a s e r ie s o f c e n t r i f u g e m o d e l s o i l t e s t s
w i t h i n t h e c o n t e x t o f t h e V E L A C S p r o j e c t . 5 I n t h e i r
r e p o r t, g o o d a g r e e m e n t o v e r a l l b e t w e e n n u m e r i c a l
s i m u l a t i o n a n d e x p e r i m e n t a l r e s u l t s w a s a c h i e v e d .
M a n y o t h e r s u c c e s s f u l n u m e r i c a l a n a l y s i s e x a m p l e s
c a n b e f o u n d i n R e f . 6 . S u c h p r o g r e s s i n a n a l y s i s a b i l i t y
s u g g e s t a p o s s i b i l i t y t o e m p l o y n u m e r i c a l a n a l y s i s f o r
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8/11/2019 Evaluation of Sheet Pile-Ring Countermeasure for oil tank site.pdf
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370 J Zheng et al.
Side wall
RC cooping
Bottom plate
Sheet pile /~
t I I I l l i l l l ,
,.c ~ , Sheet
p i l e
ring ring
Saturated
soft soil
Hard soil
Fig. 1. Outline of sheet pile-ring countermeasure.
partial verification of countermeasures against lique-
faction.
This study attempts to evaluate the sheet pile-ring
countermeasure for tank sites through three-
dimensional two-phase nonlinear finite element ana-
lysis. The liquefaction analysis code used in Ref. 5 is
adopted as analysis tool. A three-dimensional numer-
ical model of tank-ring-soil system is first estab-
lished, and the simulation of the results of
earthquake observations, 7 which are conducted at
oil tank sites with and without sheet pile-ring, is
performed to verify the numerical model. Using
the validated numerical model, the performance of
the countermeasure is evaluated by linear and non-
linear numerical simulation. In addition, the
comparison between two- and three-dimensional
analysis is carried out to test the applicability of
two-dimensional finite element analysis.
2 COUNTERMEASURE AND EARTHQUAKE
OBSERVATION
2.1 C o u n t e r m e a s u r e
Figure 1 schematically describes the principles
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