Empirical Correlations between Shear Strength Parameters and Slope Angle

Abstract

Empirical correlation serves as a guide for designers especially if there are urgent works that need to be done and a limited time to conduct extensive laboratory tests. This study defines the procedures and analysis used in order to evaluate the validity of the existing empirical correlation between the shear strength parameters i.e. cohesion and angle of friction with the slope angle by increasing the number of data points. Throughout the study, an additional of 20 sampling points were added and the soil samples were delivered to the soil laboratory for various tests such as grain size analysis, fall cone test, and direct shear test. The obtained slope angle values from field investigation and the data from laboratory testing were then analyzed and correlated. The results correlations from regression analysis showed that the coefficient of determination, R², for cohesion-slope angle and friction angle-slope angle were found to be 0.064 and 0.019, respectively, using the power series model. The values imply that there is no conclusive correlation evidence that the cohesion and angle of friction of the soil can be predicted through its respective slope angle.