Statistical Soil Type Estimation Based on Cross-plots of S-wave Velocity and Resistivity in Japanese Levees

Soil type of levee body and foundation are statistically estimated using cross-plots of S-wave velocity (Vs) and resistivity in Japanese levees. The Vs and the resistivity are collected from surface wave methods and resistivity methods. Total survey line length of the geophysical methods is about 600 km on 37 rivers in Japan. The blow counts and soil types are collected from about 400 boring logs carried out on geophysical survey lines. Vs and resistivity at the depth of the blow counts were extracted from geophysical sections. The total number of extracted data is about 4000. The data is grouped in levee body and foundation. A polynomial approximation was used to estimate the soil type from Vs and resistivity. Coefficients of equations are optimized by a least squares method. Accuracy of estimation was statistically evaluated by comparing estimated and actual soil parameters. Soil type sections were calculated from Vs and resistivity sections using the polynomial approximations.