Characterization of ground from the point of view of its excavatability

The efficient excavatability of ground is an issue that has still to be fully resolved. Although many existing criteria currently address this problem, they do not coincide with respect to the question whether mechanical methods are better than drilling and blasting for a specific type of ground. This is undoubtedly due to the variety of parameters involved.In the present study, ground in which a cut was to be made was chosen in order to compare the different existing criteria, highlighting the differences between them.To carry out this study, numerous laboratory and field trials were conducted, including the performing of mechanical tests to select the optimum method for excavating the ground in the area under study.

► Cut C1 is mainly composed of grey schists, which represent altered zones that are reddish or yellowish in colour ,Cut C-2 is composed of ground-type materials, and Cut C-3 with rocky materials (sandstones) constitute the predominant materials here.
► The results were compared with those obtained by applying the criteria of Atkinson and of Hagan & Gibson.
► To clarify the difference between criteria, a series of tests were performed in situ using mechanical excavators with different power ratings.