Theoretical Justification of the Holding Power of a Mobile Anchor for Holding Timber-Rafting Objects

Abstract

Exploitation of small and medium-sized rivers for wood transportation ensures the economic availability of wood raw materials located at a great distance from consumers. Short-term operation of timber rafting facilities and their movement from one place to another is typical for these rivers. At such facilities, the use of mobile fillable anchors is considered to be the most appropriate. The article provides a brief description of their design, installation and dismantling. The fabrication and effective application of such anchors requires appropriate justification of their parameters (the holding power, in particular). The purpose of this study is to develop the scientific basis for determining the holding power and effective application of these anchors. A theoretical justification for the process of interaction of the proposed anchor with the soil mass has been carried out. On the basis of this justification, two alternative formulas were obtained to determine the holding power provided by one section of the grouser. Calculations using these formulas give similar results. The dependences of the holding power on the determinants, such as the vertical load on one section of the grouser transmitted from the containers being filled, the coefficient of friction of the anchor material on the soil, the density of the soil, the coefficient of its internal friction and the depth of penetration of the grousers into the soil are approximately the same. Similar properties of these formulas allow to consider them reliable. The total holding power of the anchor is calculated according to the weight of the filled containers, the holding power of one section of the grouser and their number. The degree and nature of the influence of the determinants on the holding power of a mobile fillable gravity anchor have been established. An increase in any of them leads to an increase in the holding power. The most significant determinant is the vertical load on one section of the grouser. The dependence of the holding power on it is linear. To a lesser extent, in descending order, the angle of the internal friction of the soil, the coefficient of friction of the anchor material on the soil, and the density of the soil influence the holding power. The dimensions of the grouser and their change have little effect, but the very fact of their presence provides a sizeable proportion of the holding power of the anchor.