Alberto Godio

Geophysical Methods in Surveying Old Landfills

Evaluation of parameters required to diagnose state of old landfills in view of reclamation is generally performed by means of mechanical probings to obtain samples of various materials (biogas, leachate, waste, soil etc.) for analysis.

Geophysical investigation to optimize excavation of an underground marble quarry in Stazzema, Italy

A major consideration in planning underground excavation of marble is optimization of the rock extraction ratio—the ratio between the volume of the excavated void and the volume of the residual rock left in place as a supporting structure (pillars, long pillars, etc.).

Geotechnical and Geophysical Characterization of Frozen Granular Material

Degrading or thawing permafrost has been identified as being an issue of national importance with respect to its potential for causing severe damages or even loss of lives in densely populated Alpine regions due to climate change (Gruber et al. 2004; Gruber and Haeberli 2007). On this basis, a joint study was initiated by the Safe Mountain Foundation (Fondazione Montagna Sicura, Cormayeur, Italy) and some universities to investigate variations in geotechnical behaviour of the Alpine permafrost caused by changes in temperature. Permafrost is found in the Alpine regions at elevations higher than 2,500 m above sea level, depending on the location and exposure of the slope. Its mechanical features are determined by the combined effect of ice and soil particles. The water content can have an important influence on the shear resistance of the frozen soil: if the water content is low, the ice will not be able to include the soil particles. However, if it is very high, the resistance will be determined above all by the ice itself (Andresland 1987). Temperature is another driving factor that can influence the mechanical behaviour of ice (Fish and Zaretsky 1997). On this basis, this work concentrates on analysing the geotechnical and geophysical behaviour of the dispersed moraine deposits found in Alpine areas, which have been subjected to different climatic conditions due to the effect of high temperatures. The work concentrates on the geotechnical and geophysical characterization of two different glacial deposits present in the Aosta Valley region; the first one generated by the Tsanteleina glacier (Rhemes Valley, 2,690 m a.s.l.), and the second one surrounding the Blu lake (Ayas Valley, 2,214 m a.s.l.). The characterization was carried out at different scales: laboratory-scale analysis using representative granular materials and field in situ investigations, geotechnical and geophysical testing. The geotechnical measurements were performed using photographic dimension analysis of the deposit, coupled with seismic and electrical surveys. Specimens were collected, remolded, saturated, and kept in a cooler in the laboratory. The specimens were later subjected to laboratory tests to evaluate the geomechanical strength properties of the materials using (mono-axial compressive strength and Young modulus) and geophysical (P and S wave velocities) behaviour of this kind of soils are affected by temperature variations under 0 °C (−35/−5 °C).

Improved Monte Carlo Inversion of Resistivity Data

Inversion of 1D technique (VES and TDEM) by using Global Search Procedures (GSPs) as proved to be effective in evidencing local minima and equivalence problems, evaluating non-uniqueness in the solution, and estimating the values and uncertainties of the model parameters. The proposed approach is based on a Monte Carlo algorithm optimised through the application of the scale properties of the apparent resistivity curves. A statistical test selects a limited number of final models according to data uncertainties, model parameterisation and a chosen level of confidence.

Investigation of a waste landfill using electrical resistivity and induced polarisation tomography

Electrical Resistivity Tomography (ERT) and Induced Polarisation Tomography (IPT) were performed to investigate a municipal waste landfill located in the North of Italy. The object of the study is the oldest parcel of the landfill, where the waste disposal started in the early 70s and finished more than 20 years ago.