1591
Dynamic behavior of multi-arch culverts embankment considering the installation
interval of consecutive arch culverts
Comportement dynamique des terre-pleins à dalot multi-
arche en fonction de l’intervalle entre les
arches successives
Sawamura Y., Kishida K., Kimura M.
Kyoto University
ABSTRACT: Multi-arch culverts embankment is a new type of filling structure where several precast arch culverts are installed
continuously in the direction of the road extension. The shape of the embankment resembles that of a bridge structure due to the space
of the precast arch culverts and it is more open than the genaral fill method. The key in design is to estimate the practical interval
between each installed arch culvert and to clarify the interactive behavior of filling material between them in considering the seismic
influence. In this study, dynamic FEM analysis has been carried out to investigate the influence of spacing between multi-arch
culverts and mechanical behavior under seismic conditions has been discussed. From the result of numerical analysis, it is found that
when the unit interval is narrow, small maximum bending moment is generated compared with the case with wide unit interval.
Moreover, the amount of the subsidence at the center of the unit becomes small, hence unequal settlement becomes small.
RÉSUMÉ : Le terre-plein à dalot multi-arche est un nouveau type de structure de remplissage où plusieurs dalots arqués préfabriqués
sont installés de façon continue dans la direction du prolongement de la route. La forme du terre-
plein ressemble à la structure d’un
pont, du fait de l’espace entre les dalots arqués préfabriqués et de la taille de ceux
-ci, plus ouverts que dans la méthode de remplissage
traditionnelle. La clé du design est d’estimer l’intervalle e
ntre chaque arche ainsi que de déterminer le comportement des matériaux de
remplissage dans des conditions sismiques. Dans cette étude, une analyse par la méthode des éléments finis a été réalisée pour
rechercher l’influence de l’espace entre les arches et le comportement de la structure dans des conditions sismiques. D’après les
résultats de l’analyse numérique, il apparaît que lorsque l’intervalle est étroit, le moment de torsion maximal est réduit. De plus, la
quantité d’affaissement au milieu de la stru
cture diminue, ce qui réduit également le tassement inégal.
KEYWORDS: Arch culvert, Enbankment,
1 INTRODUCTION
When an arterial high-standard highway is built, it is necessary
to construct the fill or the elevated bridge to overpass other
roads and railways. Most of the time, however, the fill structure
acts as a wall that partitions an area. Unlike an elevated bridge,
that does not partition an area into two, fill structures often
create a partition, thereby obstructing the free flow of the wind
and denying people direct access. Recently, multi-arch culvert
embankments (Figure 1) of continuously arranged precast arch
culverts in the direction of the road extension are proposed as a
solution to such problems. The shape of the embankment is
close to that of a bridge structure, due to the void space of the
precast arch culverts, and it is more open than with the general
fill method. Continuous arch culverts make the structure blend
in well with the environment and beautify the scenery. The
reuse of the removed soil from the cut ground is also possible,
therefore being more economical than an elevated bridge. It is
expected that the demand for this new type of structure will
increase in the future from an economic point of view.
The design of traditional culvert structures in Japan has not
considered seismic stability, because such structures have not
suffered terrible damage in past earthquakes. Even now,
therefore, it is thought that earthquake stability need not be
considered for the range in application of traditional culverts.
However, some cases which exceed the application of
traditional culvert must be considered the seismic stability. In
multi-arch culverts embankment, since there are several arch
culverts consecutively, the behavior of arch culvert and the
surrounding soil may differ from the case with single arch
culvert, hence seismic stability must be investigated.
In the previous study (Sawamura et al., 2010, 2011), dynamic
centrifuge model test and its FEM analysis have been carried
out to confirm the difference of dynamic behavior according to
the unit interval. In the experiment, two units of arch culverts
were modeled due to the restriction of soil chamber. From the
result, experiment can be simulated accurately by using the
constitutive model and clear difference was not confirmed
because of unit interval.
In this study, the full-scale numerical analysis has been
executed to clarify the influence of the installation intervals
between consecutive arch culverts on the structures as a whole
and the surrounding soil during earthquake.
1 NUMERICAL ANALYSIS
1.1
Model of simulation
In this study, 3-dimensional elasto-plasticity FEM is conducted
using static and dynamic FEM code (DBLEAVES) developed
Figure 1. Multi-arch culverts embankment
by Ye et. al (2007). Analytical model represented a fill of 5.0 m
to be constructed on a 7.5 m thick sandy ground with
overburden height of 0.7 m above the arch culvert as shown in
Figure 2. Light fill material can be used as shown in Figure 1
for the reduction of earth pressure during earthquakes and the
