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

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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