GEOLOGICAL HAZARDS applications
Slope failures are major natural hazards occurring globally and referred to as the downslope movement of rock debris and soil in response to gravitational stresses.
Slope instabilities are generally classified according to the type of downslope movement namely falls, slides, and slows. Unfortunately, slope failure is a geohazard that impacts a wide range of population, landscapes and many types of infrastructures.
Like all geohazards, the causes are multiple and complex. Common causes of slope failure include slope steepness; drainage and stream action; water saturation; vegetation, and human alteration.
Humans alter the stability of slopes in many ways which may trigger the sudden mass movement of the soil in slopes. Some common cases include the excavation and removal of the slope’s base to build roads, the passage of heavy traffic, blasting, loading of the slope or crest, surface or groundwater manipulation, irrigation and mining.
The electrical resistivity tomography (ERT) technique provides quantitative information about the electrical resistivity values and their spatial distribution in the subsoil. Comparing geophysical models with geotechnical information (e.g. stratigraphy, water content, type of fluid in the pore), it is possible to calibrate the geophysical models obtaining the spatial extension of geotechnical parameters and allowing to define completely the boundary between lithological contacts or between water-saturated areas.
Seismic surveys are also commonly used because they provide in situ shear and compressive strength of weathered geo-materials on slopes. Therefore, the insitu geomechanical properties of the slope mass can be quickly calculated offering an extremely valuable piece of information to geotechnical engineers.