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Modern geotechnical construction methods for important infrastructure buildings
Méthodes de construction modernes des ouvrages géotechniques dans les grands projects
d
infrastrcuctures
Heerten G.
NAUE GmbH & Co. KG, Gewerbestraße 2, 32339 Espelkamp, Germany
Vollmert L.
BBG Bauberatung Geokunststoffe GmbH & Co. KG, Gewerbestraße 2, 32339 Espelkamp, Germany.
Herold A.
IBH – Herold & Partner Ingenieure, Humboldtstr. 58 b, 99425 Weimar, Germany
Thompson, Dupond J.
Same affiliation
Alcazar G.
Other affiliation
ABSTRACT: Efficient traffic routes form the basis for a brisk economic trade and a close economic and social relationship of the
European countries. Thus, the massive development of the national and international traffic routes is correspondingly important.
Especially in densely populated areas the routes have to be designed and constructed in such a way that emissions remain compatible
for the direct surroundings. In this case the modern construction management requires solutions which are well-engineered and which
can be carried out economically. The visible parts of the constructions should correspondingly suit to the landscape in an ideal way.
Thus, geosynthetics are used for the static design of high dams and noise protection barriers, in case of a foundation on extremely
weak subsoils and for ground water protection measures. Large-scale projects actually realized as well as constructions monitored
since years stand representatively for the possibilities and the importance which geosynthetics provide for the use in important
infrastructural projects.
RÉSUMÉ : L’efficacité d’un réseau routier est la base d’échanges économiques rapides et de relations étroites en matière économique
et sociale entre les pays européens. Ainsi, le développement massif des infrastructures routières nationales et internationales est par
conséquent important. En particulier dans les zones fortement peuplées, les routes doivent être conçues et construites de sorte que les
nuisances restent acceptables par le milieu environnant. Dans ce cas, la programmation de construction moderne exige des solutions
qui soient bien conçues et réalisables de façon économique. Les parties visibles d’ouvrages devraient, également, s’adapter au
paysage environnant de manière la plus naturelle possible. Pour ce faire, les géosynthétiques entrent dans la conception statique de
grands ouvrages de retenue et des barrières anti-bruit, dans la construction de remblais sur des sols d’extrêmement faible portance et
dans les ouvrages de protection des eaux souterraines. De grands projets aujourd’hui achevés ainsi que des ouvrages sous monitoring
depuis plusieurs années sont représentatifs de l’étendue des possibilités qu’offrent les géosynthétiques dans les grands projets
d'infrastructure.
KEYWORDS: geosynthetic reinforced soil, geogrid, design, regulation, Eurocode 7, infrastructure, costs, carbon footprint
1 INTRODUCTION
The reconstruction of existing and the design of new roads has
to accept the geographic situation and has to take political and
social based decisions into consideration. So not only bridges
and tunnels, but also dams and cuttings are required in areas
where the subsoil is not well suited and noise barriers have to be
built using local soils.
Geosynthetics as modern construction material are relatively
new in terms of understanding and are still not part of the
standard education. Problems of understanding synthetics are
often linked to the fact, that synthetics behave different
compared to well-known materials as concrete and are not ideal
elastic as e.g. steel. On the other hand, synthetics and wood, one
of the eldest construction material ever used by civil engineers,
are both polymers and comparable in many aspects.
Additionally, synthetics are already used in many applications
where concrete is not suitable and has to be protected against
chemicals e.g. in pipelines.
It will be shown that geosynthetics have already become an
important construction material in infrastructure applications
and allow for modern and economic constructions, saving costs
by lean structures, combining local soils, concrete and steel.
The significant reduction of the carbon footprint in many
cases seems to be a future topic, but it has started right now.
Several studies have been worked out actually, comparing
classical solutions and structures using geosynthetics, as e.g. by
Corney et al. (2009). Not only the economic effect becomes
clear in this study by requiring less energy, but also the
reduction of CO
2
during the whole process.
Egloffstein (2009) shows an example for an executed steep
slope with an inclination of 60° for a road in a hilly region of
Germany, using geosynthetics (Fig. 1). This construction had
been planned with conventional cantilever walls, but had to be
redesigned using a fully greened facing due to political reasons.
Nevertheless, the budget for the construction has been reduced
by factor 1.6 (Wessling & Vollmert). The carbon footprint - not
being a topic in 2004 - has been calculated for the well
documented wall respectively slope by Egloffstein (2009) as
given in Fig. 2. The result 6:1 stands for its own.
2 EUROPEAN REGULATIONS – ACTUAL STATUS AND
LINK TO GEOSYNTHETICS
Actually, Eurocode 7 (EC7) has become the decisive regulation
in geotechnical works for all European countries linked to EU
by law, but has not become well established up to now. All
