Simulation of seismic behaviourof gravity quay walls using
a generalized plasticity model
M.Alyami, S.M.Wlikinson, M.Rouainia & Fei Cai

Content Introduction
 Constitutive soil model Model validation
 Case study Effective stressanalysis
 Influence of density
 Conclusions

Introduction
From 1964 to 2003 well-documented case histories of damage to port structures made ofgravity retaining quay walls show that the damage is often associated with significant
deformation of liquefiable soil deposits.

Quay wall failures due to liquefaction
No.

TypeEarthquakeYear(magnitude)

PortCountry

Reference

1

Block

1964(Ms-7.5)

Niigata port

Japan

(Hayashi, et al., 1966)

2Block1985(Ms=7.8)

San Antonio port

ChileTsuchida et al. (1986):
Wyllie et al. (1986) c.f.
PIANC (2001)

3Block1986(Ms=6.2)

Kalamata port

Greece(Pitilakis &Moutsakis, 1989)

4Block1989(M=6.0)

Port of Algiers

Algeria

Manja (1999) c.f.
PIANC (2001)

5Caisson

1993(Mj=7.8)

Kushiro port West No. 1

Japan

Iai et al. (1994) c.f.
PIANC (2001)

6Caisson

1993(Mj=7.8)

Kushiro port East Quay,
Kita Wharf

JapanIai et al. (1994) c. f.
PIANC (2001)

7Caisson

1995(Mj=7.2)

Kobe port

Japan(Inagaki, et al., 1996)

8Block1999(Mw=7.4)

Derince port

TurkeySugano and Iai (1999)
c.f. PIANC (2001)

9Caisson1999(Ms=7.7)

Taichung port

TaiwanSugano et al. (1996)
c.f. PIANC (2001)

Constitutive soil model(Pastor, Zienckiecwz & Chan, 1990) (PZ-III)
 (Elasto-Plasiticity) with minor modifications







The progressive decrease in the stiffness of soil with increasing
pore pressure
Accumulation of deformation
Stress Dilatancy
Hysteresis loops

Modified (PZ-III) has 15 Parameters, which should be obtained
from monotonic and cyclic traixial tests

Model evaluation

PI Masado sandToyoura sandToyota and his group, 2004

Finite element code The UWLC used in this study is a fully coupled finite

element code based on the u-p formulation..

M u + Ku − Qp = f ( u ).

.

Q u + Hp + S p = f ( p )T The primary variables in this form are solid

displacements (u) and fluid pressure (p) Newmark method is used to integrate the above
equations in time domain

The Case Study
Kobe Port (Port Island Quay Wall) during 1995 earthquake

BerthFrom The Port and Harbour research institute
Ministry of Transport, Japan (1997)

Displacements (m)Horizontal

VerticalPC 1

2.75

1.36

PC 1 extension

3.13

1.01

PC 2

2.33

0.79

PC 3

2.46

1.14

PC 4

2.37

1.40

PC 5

2.30

1.38

Model parameters

Cyclic stress ratio from triaxial tests
on samples from Port Island
conducted by Nigase

Geometry (in natural scale) and material zones of thePort Island PC1 quay wall

Recorded motions at Kobe Port during the 1995 reported by Iwasaki & Tai (1996)
Vertical (U(U-D) component 200gal (cm/sec2)
Horizontal (E(E-W) component 460gal (cm/sec2)

Displacements

Pore pressuresbuilt upEffective Stress analysis.

ADeformation at the end of earthquake t = 30sec
Vertical displacement

Horizontal displacement

0.73m (0.79m to1.40m measured)

3.28m (2.3m to3.13m measured)

From The port and harbour research institute ministry oftransport, Japan (1997)

Influence of relative density

Horizontal displacement

Vertical displacement

Distributions of excess pore water pressure

Conclusions
A two-dimensional effective stress method of analysis based on the elasto-plastic constitutive
model of PZ-III with slight modifications has been used for the analysis Port Island quay-wall PC1.
 The model was first validated by simulating published cyclic test results. The results of thetesting showed excellent agreement between the physical and numerical experiments.
 Port Island quay walls was then analyzed using a finite element package UWLC Computed overall displacement and rotations of the wall were similar to those observed in thefield.
 Improving the foundation while the backfill remained loose caused slightly smaller residual
deformation of the caisson than when both the foundation and backfill were improved.
 The weight of the wall acting on the foundation leads to increased confining pressure beneaththe wall, which prevents the occurrence of liquefaction behaviour.
 Finally, effective stress analysis is a powerful tool that can describe the seismic response of port
structures, including liquefaction failure modes.