Assessment in Baku Azerbaijan
a major landslide, concerning an area of some 15 ha, which occurred
abruptly on March 7, 2000 in the Bayilev zone of the Sabayil district,
South of Baku city center, DRM was charged by the World Bank to
provide a technical assistance in order to determine the adequate
remediation and prevention works to be carried out. The available
information on the landslide activity in the concerned zone was
reviewed on site by an expert of EPFL, in order to identify the
future risks of landslides, to propose possible remedial and monitoring
works and to give some advice on the use of the surrounding areas.
The expert was also asked by the Vice Prime-Minister of Azerbaijan
to assess the remediation works already carried out and the necessity
of relocating endangered houses near the landslide.
data on the topographical, geological and geotechnical conditions
could be obtained, but it was quite difficult to get information
on actual damage and repair work costs, as well as on climatic and
hydro geological conditions. All the gathered information was analysed
in order to do extensive stability computations, so as to assess
the efficiency of the various planned stabilizing actions.
analysis of the landslide mechanism and of its causes revealed that
it was a single compound slide with one slip surface in fairly unfavourable
geological conditions, which was mainly triggered by very important
rainfall in October and November 1999 (more than the average annual
precipitation occurred in two months). Due to the low permeability
of the soil, the groundwater table was slowly recharged; but the
investigations after the disaster showed that the crack openings
in the landslide zone had allowed a significant lowering of the
water table. Some water leakage from utility lines crossing the
slide may also have had a detrimental preparatory effect.
main design adopted was to trim the whole slope that is to recreate
a smooth regular ground surface from the toe to the top. But it
has to be complemented by drainage and above all toe loading, rather
than by building a double row of piles in the lower part of the
slide as it was designed locally. Furthermore, it has been advised
to develop a comprehensive monitoring program to control the safety
conditions in the vicinity of the scarp and check the efficiency
of the stabilizing works.
total costs induced by the landslide appeared much smaller than
the initially announced losses of 23 million US $. They can presently
be assessed as less than 4 million US $, depending on the amount
spent for the resettlement of evacuated persons.
some recommendations and conclusions have been expressed concerning
the stabilization works, the monitoring and control of the affected
zone in order to limit its use during the first five years; then
it will be possible to determine if restricted planning within the
damage zone may be modified.