SOIL DYNAMICS OF SINGLE AND MULTIPLE TINES AT SPEEDS UP TO 20 KM H/

A force prediction model has been developed for single and multiple ti nes at speeds at which inertial effects are signficant. The soil worke d by the tines is assumed to obey the Mohr-Coulomb criterion. The mode l can be extended to estimate the dynamic forces in adhesive soils by revising tine rake angle to account for geometry changes resulting fro m the soil body adhering to the tine. Results of experiments carried o ut between speeds of 1 and 20 km/h are reported for both frictional (l aboratory) and cohesive (field) soils and comparisons are made between theoretical and measured values. The predicted forces agreed with exp erimental data and in the majority of cases the magnitude of the diffe rence between the predicted and experimental data was less than the le ast significant difference between treatment means at the 0.05 probabi lity level. (C) 1996 Silsoe Research Institute