Pilot-scale studies have been made of the operation of dump trucks and a towed scraper on soil in a range of controlled conditions close to the limits of trafficability of the plant. General expressions were determined relating depth of wheel rut, rolling resistance and the moisture condition value (mcv) of the soil and also, for self-propelled plant, relating wheel slip to rolling resistance. Comparisons have been made with the results of an earlier study where observations were made of plant operations on road construction sites. Based on the results of the study, the limits of effective operation of various types of earthmoving plant are given in the form of relations between the mcv of the soil and the loaded mass of the machine. The findings largely supersede those given in an earlier report (LR 1034). (Author/publisher)
Abstract