2055
Shaking table tests on caisson-type quay wall with stabilized mound
Essais à table vibrante sur les murs de quai de type caisson avec butte stabilisée
Mizutani T.
Geotechnical Engineering Field, Port and Airport Research Institute
Kikuchi Y.
Professor, Department of Civil Engineering, Tokyo University of Science
ABSTRACT: Caisson-type quay walls were one of the major types of quay walls in Japan. It was desired to increase the front-water
depth of them, because vessels coming alongside them become larger and larger. The authors have been studying on a new
construction method for the improvement. The method consisted of two steps. Step 1 was to solidify a part of rubble mound beneath a
caisson and step 2 was to cut it to increase the front-water depth of the caisson. A series of shaking table tests were conducted to study
the seismic behavior of caisson-type quay walls improved by the new method. This paper will introduce the test results and discuss
the factors which affected the seismic behavior of the caisson-type quay walls with stabilized mound.
RÉSUMÉ : Les murs de quai de type caisson constituent l’un des types majeurs de murs de quai au Japon. On a désiré augmenter la
profondeur frontale face à la mer car les navires venant acccoster le long des quais deviennent de plus en plus gros. Les auteurs ont
étudié une nouvelle méthode de construction afin d’apporter des améliorations. Cette méthode est constituée de 2 étapes. La 1ère
étape consiste à solidifier une partie de la butte de gravats sous le caisson et la 2ème étape à le découper afin d’augmenter la
profondeur frontale du caisson. Une série d’essais à table vibrante a été menée afin d’étudier le comportement sismique des murs de
quai de type caisson qui ont été améliorés grâce à cette nouvelle méthode. Cette étude présente les résultats des essais et analyse les
facteurs qui affectent le comportement sismique des murs de quai de type caisson avec butte stabilisée.
KEYWORDS: caisson-type quay wall, front-water-depth enlargement, shaking table test
1. INTRODUCTION
In recent years, there has been increasing demand to reduce
costs for public works in Japan. Correspondingly, great efforts
have been directed toward using and upgrading existing
infrastructures efficiently. In this context, the authors have been
studying methods for enhancement and improvement of existing
port facilities.
Because the caisson-type quay wall (see Figure 1) is one of
the major types used in Japan (OCDI 2009), it is desirable that
this type quay wall have more front-water depth to better
accommodate the larger and larger vessels coming alongside. A
method often employed for this improvement is to construct a
new pier front onto the caisson quay wall as shown in Figure 2.
It is impossible, however, to adopt this method for a caisson
quay wall when there is not enough frontal space: thus, a new
improvement method applicable to such situations is being
developed. In the new method, a rubble mound beneath a
caisson is solidified then cut to increase the front-water depth of
the caisson as shown in Figure 3.
The authors conducted a series of shaking table tests to study
the seismic behavior of caisson-type quay walls improved by
the new method.
2. TEST METHOD
A model of a caisson quay wall was built in a sand box whose
inside dimensions were 85cm in length, 35.4cm in width and
65cm in height. Figure 4 shows a schematic view of the model.
The gravel layer at the bottom of the sand box was part of the
box (for drainage). It was compacted sufficiently and it was
assumed that the deformation of the gravel layer would not
affect test results. A non-woven fabric was put on the surface of
the gravel layer for sand prevention. The tests focused on the
vibrational property and deformation mode of the quay walls
with a stabilized mound; the model ground was dry for
simplicity.
Figure 1. Typical cross-section of the caisson-type quay wall.
Figure 2. Construction of a new pier to enlarge the front-water depth of
the caisson-type quay wall.
Figure 3. The new method to enlarge the front-water depth of the
caisson-type quay wall without change in the face line of the quay wall.
