Equivalent Quasi-Static Estimation of Dynamic Penetration Force for Near Surface Soil Characterization

This paper describes the application of maximum log-likelihood estimation to estimate the average force during a dynamic penetration. It is used to obtain a quasi- static equivalent of the dynamic force in Rapid Soil Characterization System (RapSochs). The force is measured at the tip and friction sleeve by strain gauges during hammer blows. The results are necessary for any analyses similar to Cone Penetration Test (CPT) data analysis. This method is proven to result in an acceptable estimation of the force (the soil resistance) in different soil types. It is shown that the cone resistance, friction resistance and friction ratio similar to CPT can be obtained and these are plotted versus depth. It is also shown that the estimated soil resistance does not depend on the applied energy and variable hammer drop height.