Implementation of in-situ and geophysical investigation methods (ERT & MASW) with the purpose to determine 2D profile of landslide

Influence of region lithostratigraphic composition has a dominant effect on the development and shape of the landslide slide surface. Paper contemplate 2D profile model of a retrogressive landslide along with the implementation of "in situ" and geophysical investigation methods for the landslide instability with the complex slide surface. Purpose of the investigation works is to obtain insight in the ground composition and geotechnical characteristics of the soil on the area of the manifested landslide, identification of the slide surface as well as the creation of geotechnical soil profiles. To determine position and size of the surface of rupture, investigation works have been undertaken involving: core drilling, dynamic probing by the light dynamic probe (DPL), flat dilatometer probing (DMT) and static probing by CPTu probing. Used geophysical methods comprised geoelectrical tomography (ERT) and multichannel seismic analysis of surface waves (MASW). ERT tomography method can be considered appropriate for geometrical landslide outlining, as well as recognising potentially unstable slope areas. From the other side, electrical profiling results need to be calibrated with data obtained from other in-situ investigations. This was accomplished by use of In-situ probes, CPTu and DMT. Obtained 2D profile of the landslide model was additionally arithmetically confirmed by the use of limit equilibrium methods. Investigation results accomplished by the combination of proposed investigation methods have been proved as a good base for the exploration of the complex landslide instabilities.