1930
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
7. ACKNOWLEDGEMENTS
The authors would like to express their gratitude to all colleagues with
the Investor, Consultants and Contractors for the excellent and compe-
tent collaboration during all project stages and even (and particularly)
in some difficult phases.
8. REFERENCES
Alexiew, D. (2004)
:
Geosynthetic Reinforced Slopes: Basics of Design and
some Projects.
Proc. of the Indian Conference Geosynthetics – New Hori-
zons,
New Delhi, India: 73 – 85
.
Alexiew, D. (2005). Zur Berechnung und Ausführung geokunststoffbewehrter
"Böschungen" und "Wände": aktuelle Kommentare und Projektbeispiele.
Proc. 5. Österreichische Geotechniktagung,
ÖIAV, Wien, Austria: 87 –
105
.
CDBSSR Code for the design of buildings and structures in seismic regions
(1987).
KTSU & BAN
, Sofia, Bulgaria. (in Bulgarian)
Figure 8. Left: construction stages (formwork, geogrids, anchor bars, facing),
right: top view of the stone-filled facing used.
CDRW Code for the design of retaining walls (1986).
MBI Ministry for build-
ing industry
, Bulletin BSA, Vol. XXX/10, Sofia, Bulgaria. (in Bulgarian).
DIN 1054. Baugrund - Sicherheitsnachweise im Erd- und Grundbau (Ground -
Verification of the safety of earthworks and foundations),
Deutsches Insti-
tut für Normung
, Berlin, Deutschland.
DIN 4084. Baugrund - Geländebruchberechnungen (Soil - Calculation of em-
bankment failure and overall stability of retaining structures),
Deutsches
Institut für Normung
, Berlin, Deutschland.
EBGEO 2010 Recommendations for Design and Analysis of Earth Structures
using Geosynthetic Reinforcement,
DGGT / Ernst & Sohn
, Essen/Berlin,
Deutschland.
Jossifowa, S. and Alexiew, D. (2002). Geogitterbewehrte Stützbauwerke an
Autobahnen und Nationalstrassen in Bulgarien,
Proc. 12. Donau-
Europäische Konferenz „Geotechnisches Ingenieurwesen“,
DGGT, Pas-
sau, Deutschland: 389-396.
SGDSR Specialties in the geotechnical design in seismic regions (1987).
MBI
Ministry for building industry
, Bulletin BSA, Vol. XXXII/11, Sofia, Bul-
garia. (in Bulgarian).
Tatsuoka, F., Koseki, J., Tateyama, M., Munaf, Y. and Horii, N. (1998): Seis-
mic stability against high seismic loads of geosynthetic-reinforced soil re-
taining structures. Keynote Lecture.
Proc. 6
th
International Conference on
Geosynthetics
, Atlanta; USA, 1: 103 - 142.
Figure 9. Top view of a completed GRS-wall.
6. FINAL REMARKS
The new Road III-868 from Devin to Mihalkovo in the Rhodope
Mountains in southern Bulgaria was a challenge in terms of optimal
concept, design, execution, re-design during execution, time schedule
and costs. It crosses a terrain with sophisticated topography and geol-
ogy in a seismic region. Its length amounts to 11 km comprising one
tunnel and twenty geogrid-reinforced almost vertical soil walls of to-
tally 2 km length and up to 20+ m height.
A specific type of facing was adopted to fulfil a wide range of re-
quirements.
Almost all GRS-walls had to be re-designed and adopted under
running route execution, resulting throughout in non-common high
bermless solutions.
Nevertheless, it was possible to meet all project goals regarding
time schedule and costs (among others; see the description of criteria,
goals and optimized solution in Chapter 1). The success is based on
the one hand on the advantages and flexibility of geosynthetic solu-
tions in geotechnical engineering in terms of easy and quick construc-
tion process and adaptation and on the other hand on the excellent co-
operation of all participants: Investor, Owner, Consultants,
Contractors and Geosynthetic Company.
The road is since summer 2010 under traffic, the GRS-walls dem-
onstrate until now an excellent behavior both in terms of stability and
low deformability.
This transportation project is may be the most distinctive in the
Balkan region during the last years.
