Field observations of the performance of rock cutting trenchers
Although a general idea exists which rock properties influence tool consumption and production, studies which are devoted to back analysis of cutting or drilling projects are scarce. The validity of the ideas developed during this research was examined by studying the performance of rock cutting trenchers. Most probably the general model developed from these observations will apply to other excavation machines working on the drag cutting principle. To be able to study the rock cutting performance, the assumption was made that soil overburden or highly to completely weathered rock would not contribute significantly to the wear of the cutting bits, as compared with the contribution of massive rock. The excavation rate in rock was established by multiplying the advance rate of the trencher by the width of the trench and the thickness of the rock unit. The trencher observations clearly show that two main modes of excavation can be distinguished: cutting and ripping.