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Titel |
Impact of large slope movements on the construction of a major highway in the Constantine Province, North-East Algeria |
VerfasserIn |
H.-B. Havenith, S. Draidia, C. Benabbas |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250063879
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Zusammenfassung |
All over northern Algeria, mass movements represent a major hazard and frequently impact
on infrastructure, causing significant losses.
This paper presents first results of the analysis of slope instabilities along a highway
under construction in the Tafrent Region, Constantine Province. They show that
many different types of failures characterized by a high degree of heterogeneity
affect the road works. Some appear as clear landslides, others develop as diffuse
movements in zones previously classified as stable areas. Most of the recent slope
movements were triggered during the road works involving extensive removal of
rock and soil masses. Some instabilities initiated within paleo-landslides and now
affect entire mountain slopes larger than 50 ha. Due their large size (with a volume
reaching more than 106 m3) it is likely that remediation measures will be very
costly. Therefore, it is necessary to assess the full impact potential of these slope
instabilities.
First, we started to make the inventory of all slope instabilities within a large corridor
along the highway. Second, detailed geomorphologic and structural geology analyses using
remote sensing (based on aerial photographs and SPOT imagery) and field observations are
performed. Third, many geotechnical tests complemented by sedimentological analyses
provide valuable data on the geomechanic behaviour of the soils that are mainly made of
weathered marls and often exhibit viscous types of movements that affect the entire unstable
mass.
The specific target of our work is to answer the following questions: how much did the
road works modify the natural state of stability, could the reactivation of paleo-landslides be
predicted, might it have been prevented and, finally, can further slope movements be
predicted – and, thus, their impacts prevented?
The development of a robust methodology based on remote sensing, field observations
and geotechnical-geophysical investigations is the general goal of our research. This
methodology could then be applied to other regions since the need for assessing
landslide hazards is very high all over the mountainous areas of Northern Algeria. |
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