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Concrete panel walls – Current development on interaction of earthworks,
geosynthetic reinforcement and facing
Comportement des parements béton de murs de soutènement en sols renforcés – interaction entre
les sols remblayés, le renforcement et le parement
Vollmert L., Niehues C.
BBG Bauberatung Geokunststoffe GmbH & Co. KG, Espelkamp, Germany
Pachomow D.
Technische Universität Cottbus, Cottbus, Germany
Herold A.
IBH – Herold & Partner Ingenieure, Weimar, Germany
Verstraaten W.
KWS Infra b.v., De Meern, The Netherlands
ABSTRACT: Reinforced soil structures have become an appropriate construction method for infrastructural buildings. Several types
of facing are commonly used. Full height panels or segmental panels with a certain height are mainly used for flyover constructions
and bridge abutments. The design of the constructions depends on the stiffness of the facing element. Large scale test with loads up to
450 kPa at laboratory conditions as well as on site test with one year of continuous measurement under weathering conditions are
presented and compared to analytical design and calculations using commercial finite element software. The results indicate that this
type of structure can be designed on the safe side using current design standards and benefits given by the interaction of stiff geogrid
reinforcement and soil.
RÉSUMÉ : Les ouvrages en remblai renforcé sont devenus une méthode de construction adaptée aux projets d’infrastructures.
Plusieurs types de parement sont couramment utilisés. Des panneaux de pleine hauteur, ou panneaux segmentaires avec une certaine
hauteur, sont principalement utilisés pour les constructions surélevées et les culées de pont. La conception de ces ouvrages dépend de
la rigidité de l’élément de parement. Cet article présente des essais réalisés à grande échelle avec des charges allant jusqu’à 450 kPa,
en condition de laboratoire ainsi que sur site, avec une année de mesure en continu en condition de vieillissement. Les résultats sont
comparés à la conception analytique et aux calculs réalisés à l’aide d’un logiciel commercial d’éléments finis. Les résultats montrent
que ce type d’ouvrage peut être conçu de façon sécuritaire suivant les normes de conceptions actuelles et les avantages apportés par
l’interaction d’une géogrille rigide avec le sol.
KEYWORDS: geosynthetic reinforced walls, concrete, design, testing, execution, DIN EN 14475, EBGEO, BS8006
1 INTRODUCTION
Creating robust and sustainable constructions in geotechnical
engineering has become an upcoming topic in terms of
reduction of carbon footprint as well as on cost reduction on
PPP projects. Combining technologies for slim precast concrete
panels with stiff geosynthetic reinforced walls allows for the use
of local and in some cases even treated soils.
In the last years recent research has led to further
understanding of reinforcing interaction, leading to design
approaches published in EBGEO and allowing for a reduction
of lateral stress on the facing constructions.
Design of precast panels in practice requires attention to the
transport phase as well as on the construction steps during
execution and serviceability limit state.
2 DESIGN OF REINFORCED STRUCTURES
DIN EN 14475, the British design code BS8006 as well as the
German design recommendations EBGEO are state-of-the-art
standards in order to safeguard the constructions.
Special attention has to be paid to the design of the facing, as
these elements are directly exposed to the environment and
deformations of the construction can be seen immediately. The
mentioned design codes do not give a unique calculation of
lateral stress acting on the facing elements. DIN EN 14475
already differentiates between several types of facing elements,
depending on the stiffness:
Rigid facings, e.g. full height panels
Semi-flexible facings, e.g. concrete blocks without rigid
connections, gabion baskets
Flexible facings, e.g. wrap-around method
The lateral stress has to be different from the active earth
pressure calculated according to Rankine´s theory due to the
geosynthetic reinforcing elements, “nailing” the fictive failure
zone. As this becomes a hyper static system, the earth pressure
distribution on the facing is indifferent
.
Nevertheless, the design has to be proper and worked out on
the safe side, so additional information has to be gained from
sites and large scale tests, especially taking influence of water,
subsoil settlements and installation conditions (compaction,
construction steps, etc.) into consideration.
3 CURRENT DEVELOPMENT
3.1
Lateral stress on facing
Pachomow et al. (2007) collected several test-field data of
executed walls in heights between 2.0 m and up to 30 m, with
information concerning the lateral pressure on the facing given.
It is interesting that the lateral stress gained by self-weight of
the construction remained within a range of up to 50 kPa,
although significant higher values would have been expected
especially for high walls.
Normalising the height of all test field data, and recognising
that nearly all data are linked to non-cohesive soils as well as to
slope inclinations between 70° and 90°, the relationship
between the vertical and lateral stress can be compared to the
