Distortion in the similitude of soil-machine systems

This paper contains an appraisal of the current knowledge concerning sources of distortion in similitude studies and techniques used to deal with it. The general philosophy and basic principles that relate the concepts of similitude and studies of soil-machine systems have been discussed in detail in the paper, Similitude Studies of Soil-Machine Systems by Freitag et al. Some of that material is repeated to help define the condition referred to as distortion and to establish the effects of distorted models in the application of similitude to the analysis of soil-machine systems.