Finite Element Analysis of Multipass Effects of Vehicles on Soil Compaction

FINITE element procedure was used to simulate multiple wheel loading and to predict its effect on soil compaction. Results of nonlinear analysis, conducted using an incremental loading procedure, show effects of tire size, soil type, and number of passes on soil compaction . The results of the study also demonstrate the potential use of the procedure in compaction related studies. However, experimental verification of the model is necessary before the procedure can be recommended for wider use. INTRODUCTION Effects of soil compaction on soil structure, texture and strength , and on plant development and crop yields have received considerable attention from researchers in the past (Klingbiel and O' Neal , 1952; Ingles, 1974; Fountaine, 1958; Negi et al. , 1980; Chancellor, 1971; Camp and Gill, 1969; Eavis and Payne, 1968; Rosenburg and Willits, 1962; Voorhees, 1977). In recent years , there has been a growing interest in machine-induced soil compaction, perhaps because of the steady increase in the size of field machines as well as increased use of conservation or no-tillage practices. During most agricultural and forestry operations, a significant portion of the site will be exposed to single or, at times, multiple passes of vehicles. The compaction which can result from this single or multiple loading will depend on factors such as soil and vehicle type, soil moisture level, number of passes, vehicle weight, contact pressure, etc. Most studies dealing with vehicle loading and soil compaction have been experimental. One disadvantage with the experimental procedure is that it is laborious, time consuming, and expensive. An alternative is to develop a mathematical model capable of describing the soil-tractive device interaction . Combined use of such a model and experimental procedure should be helpful to better understand the effects of various soil and vehicle parameters on soil compaction as well as the machanics of soil compaction . Therefore, the overall objective of this study was ·to develop a numerical procedure to predict the soil compaction from multiple wheel loadings. The specific objectives of the study were: 1. To develop a finite-element model to predict the The authors are: D. POLLOCK, JR. , Mechanical Engineer, Belvoir Research and Development Center, Fort Belvoir, VA; J. V. PERUMPRAL, Professor, Agricultural Engineering Dept., and T. KUPPUSAMY, Associate Professor, Civil Engineering Dept., Virginia Polytechnic Institute and State University, Blacksburg, VA . "[ _.,_ lli so1 sur ace ...-::; ::r-