Accession Number : AD0778717

Title :   Trafficability of Soils. Supplement 20. Development of Vehicle Performance Prediction Equations and Classification System for Coarse-Grained Soils.

Descriptive Note : Technical memo.,


Personal Author(s) : Kennedy,James G.

Report Date : APR 1974

Pagination or Media Count : 77

Abstract : The report presents techniques for estimating vehicle performance capabilities in coarse-grained soils (clean sands) and a scheme for classifying dry-to-moist sands for trafficability purposes. Earlier test programs showed a need for separation of sand into two categories: wet sand and dry-to-moist sand. Dry-to-moist sands only are presented in this report, since wet sand is usually temporary, making wet-sand strength a time-dependent variable difficult to correlate with vehicle performance. Equations are derived for predicting the performance of all-wheel-drive wheeled vehicles based on sand strength (cone index), tire characteristics (inflation pressure, sizes, etc.), and gross vehicle weight. Performance parameters are maximum slope negotiable, maximum drawbar pull (maximum towing force), and minimum sand strength required for a vehicle to negotiate level sand (vehicle cone index). An equation is also derived for predicting motion resistance for wheeled vehicles (self-propelled type or towed trailers). (Modified author abstract)

Descriptors :   *Soils, *Trafficability, Soil classification, Sand, Vehicles, Performance(Engineering), Predictions, Mobility, Offroad traffic

Subject Categories : Soil Mechanics
      Surface Transportation and Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE