Study of deformation properties of road foundations of the mixed type intended for the movement of mobile complexes for monitoring and transporting raw materials

Abstract

Analysis of the conditions of movement of mobile robotic complexes showed that about 70% of the time of movement is made up of sand, gravel and sandy areas. In winter, it is covered with snow. An unsolved problem is the traffic conditions during the transition period, namely, movement on snow-sandy support bases. This paper is devoted to the study of road and soil foundations, i.e. mixed surfaces consisting of sand and snow. A method for obtaining mixed surfaces (mixtures) with different percentages is described. It is shown how the measurements of the density and fractional composition of the sand were carried out. It also shows how the snow density was measured. Examples of test fragments are given. A test procedure for measurement of deformation properties is presented. “Load-deformation” curves are provided. The study reveals how the sand and snow percentage affects the curve behaviour. Dependencies are given to describe the process “load deformation” for sand and snow. The dependence of the mixtures is proposed. The generalized dependence includes the dependences of Goryachkin - Letoshnev and Malygin. This paper also specifies the curve behaviour for an undisturbed road and soil foundation, and a surface exposed to an operating mover or a utility vehicle. It is shown that for mixtures of various compositions for an intact surface and under repeated loading, the difference in stresses is from 1.25 to 5 times.