Discussion of correlations between geotechnical and electrical data; case studies at France and India
Speaker: Ze-Zong Lin
Abstract
Using different parameters to find the correlations between geotechnical data and electrical data . The first case (in France) use the cone resistance(qd value) compare with the inverted resistivity ( ρ value). The second case (in India) use the average number of blow (N value) compare with the transverse resistance (T value). In first case, geophysical (Electrical Resistivity Tomography, Ground Penetrating Radar profiles and seismic refraction) and geotechnical (dynamic penetrometer, in situ vane test) surveys were carried out at Garchy (Nievre, France). The main objective of this case was to establish qualitative and quantitative correlations between electrical and geotechnical data. No clear relationship between cone resistance and inverted resistivity extracted from ERT sections has been observed. In second case, Electrical Resistivity Tomography (ERT) has been used in association with Standard Penetration Test (SPT) and Dynamic Cone Penetration Test (DCPT) for Geotechnical investigations at two sites, proposed for thermal power plants, in Uttar Pradesh (UP), India. The concept of electrical resistivity variation with soil strength related to the grain size distribution, cementation, porosity and saturation has been used to correlate the transverse resistance of soil with the number of blow counts (N-values) obtained from SPT and DCPT data. It was thus observed that the transverse resistance of soil column is linearly related with the number of blow counts (N-values) at these sites.
Reference
Philippe Cosenza, Eric Marmet, Faycal Rejiba, Yu Jun Cui, Alain Tabbagh, Yvelle Charlery, 2006. Corrections between geotechnical and electrical data; A case study at Garchy in France. Journal of Applied Geophysics 60, 165-178.
Kumari Sudha, M. Israil, S. Mittal, J. Rai, 2009. Soil characterization using electrical resistivity tomography and geotechnical investigations. Journal of Applied Geophysics 67, 74-79.