Model studies of the failure mechanism associated with a sphere rolling down a soil slope

Abstract

INTRODUCTION OWING to the complexities in the analysis of wheel-soil interaction, much effort has been devoted to experimentally determined empirical performance parameters. For the same reasons, less attention has been paid to fundamentals of wheel-soil interaction. Although performance parameters may be of more immediate interest for a particular design, an understanding of wheel-soil interaction is essential for developing theory applicable for general prediction and design. It appears reasonable to anticipate that wheel-soil interaction depends on the soil failure mechanism. This paper describes model studies enabling further insight into this mechanism. This failure mechanism, although specifically investigated for a rigid sphere--a spherical wheel, is believed to be applicable to other cases of wheel-soil interaction as well. This research was part of a more extensive study wherein the pressure distribution was investigated, and theory was proposed for analysis of freely rolling or pulled rigid spherical wheels. The results of these phases of the study are reported elsewhere [1]. The overall study was directed at the study of lunar problems in soil mechanics and vehicle mobility.