INFLUENCE OF THE RESISTENCE TO PENETRATION AND SHEARING ON THE EXECUTION STEPS OF THE HOLES FOR PLANTING SAPLINGS PUBLISHEDN. BOJA, F. BOJA, A. DARAU
The present research displays the results obtained after the digging of holes for planting saplings in a previously unprepared soil, following the steps to carry them out according to some physical-mechanical properties of the soil. The research was carried out on a horizontal ground in the Forest District Iuliu Moldovan, in two forest compartments 31 C and 32 A, in a previously unprepared ground, on two types of soil: gley-soil (the muddy subtype) and alluvial soil (the vertical-gleyed subtype), and in Forest District Radna, forest compartment 74, on a brown typically luvic soil, using the Stihl BT 121 motto-borer with a 200 mm drill. The objectives of the research were to make a comparative determination, on different types of soil, of the qualitative parameters, among which the most important ones are: degree of loosening of the soil taken and left in the hole, resistance to penetration, resistance to shearing, timing of drilling holes, using the Stihl BT 121 motto-borer in order to establish its technical efficiency.In order to observe the influence which the drilling of holes has on its walls, we measured the resistance to penetration and resistance to shearing every 10 cm at a 30 cm depth, the proper depth for planting small-sized saplings, on two opposing sides, so that we could get the most probable values of these physical-mechanical properties of the soil. After taking the measures in order to establish the compaction degree of the wall and of the bottom of the hole by the borer in that interval, it was judged that in conditions of normal humidity, if the borers have sharp knives and are well conceived and executed from a technical point of view, there are no big values of the resistance to penetration which could affect the subsequent development of the saplings. The usefulness of the present paper stays in the research data collected, processed, analyzed and valorized in order to offer a pertinent study material, which could indeed be used by specialists in designing the process for obtaining, through a mechanized means, the holes for planting small-sized saplings on a horizontal ground, using the Stihl BT 121 motto- borer.
motto-borer, resistance to penetration, average time of drilling, degree of scattering, degree of evacuation.