Hb. Havevith et al., Geophysical investigations of seismically induced surface effects: Case study of a landslide in the Suusamyr valley, Kyrgyzstan, SURV GEOPH, 21(4), 2000, pp. 349-369
In summer 1998, a geophysical survey including seismic profiles and electri
cal tomography has been carried out in the Suusamyr valley, Kyrgyzstan. The
scope was to investigate surface effects induced by the Ms = 7.3 Suusamyr
earthquake, the 19th of August, 1992. In this paper, special attention is p
aid to the case study of a debris slide triggered by the earthquake. Seismi
c data are analysed by P-wave refraction technique and by surface wave inve
rsion. Electrical tomographic profiles are processed by 2D-inversion.
Using geotechnical and geological information, P-velocity models and resist
ivity sections are interpreted in terms of geological materials, in order t
o build a geological 3D model. On the basis of the latter, we carried out s
tatic finite element computations as well as static and pseudo-static calcu
lations with Janbu's method. Newmark displacement was computed, considering
or not the influence of the shallow soft deposits. The results are compare
d to the real displacement observed in the field and conclusions are drawn
about the mechanism of the landslide.