Yoshinori Ohira

Comparison of strength and soil thrust characteristics among different soil shear tests

Abstract The many factors which influence shear properties obtained by vane shear test are considered. The shear properties obtained by vane tests are compared with those by a direct shear test (shear box) and an unconfined compression test, and the differences of shear properties among these three tests are discussed. Further, the anisotropic characteristics of the strength of the clay samples used are considered.

Prediction of sinkage and motion resistance of a tracked vehicle using plate penetration test

Abstract The relationship between contact pressure and sinkage must be represented by a mathematical model to estimate the sinkage and the motion resistance due to a vehicle. In this study an approximate and simple pressure-sinkage model is proposed. This model takes into account the effect of the size of the penetration plate on soil response, and includes two soil values that can be obtained by a single plate penetration test. It is submitted that the sinkage and the motion resistance of a tracked vehicle can be estimated by means of the proposed model.

Basic study of probabilistic approach to prediction of soil trafficability — Statistical characteristics of cone index

Abstract The principal purpose of this study is to present some of the fundamental data which might be used in the prediction of soil trafficability. These data are based on some sets of random cone index measurements which were taken from the areas of interest. In all cases, it was assumed that the individual measurements of the cone index being investigated would be independent. It is shown that the cone indices at critical layer depth can be regarded as normal random variables. The discussion in this study may be valid for the probabilistic approach of soil trafficability

A simplified method for the estimation of soil thrust exerted by a tracked vehicle

Abstract A simplified method for estimating the soil thrust exerted by a tracked vehicle is proposed. The relationship between the soil shear torque curve (shear torque-deformation curve) obtained from ring shear test and the thrust curve (soil thrust-slip ratio curve) of a tracked vehicle is analyzed and it is shown that there is a transformation law between these curves. A simplified analytical method for estimating the soil thrust exerted by a tracked vehicle is developed by using the above-mentioned transformation law. Soil thrust can be estimated by using the soil shear torque curve, shear ring and vehicle parameters. It is experimentally confirmed that the soil thrust can be easily estimated by using the proposed method.