Characterization of the Avignonet landslide (French Alps)with seismic techniques

摘要

The large Avignonet landslide (40×106m3) is located in the Trieves area (French Alps) whichis covered by a thick layer ofglacio-lacustrine clay. The slide is moving slowly at a rate varying from 1cm/yearnear the upper scarp to over 13 cm/year at the toe. A preliminary geophysical campaign was performed in orderto test the sensitivity of geophysical parameters to the gravitational deformation. In the saturated clays wherethe landslide occurs,the electrical resistivity and P-wave velocity are little affected by the slide. On the contrary,S-wave velocity (Vs) values in the first ten meters were found to be inversely correlated with the measureddisplacement rates along the slope. These results highlight the interest of measuring Vs values in the field forcharacterising slides in saturated clays and of developing techniques allowing the 2D and 3D imaging of slides.