Determining the soil constant parameters with a novel and functional view in the Soil Bin

ABSTRACT: One of the most important issues in mechanic of soil discussions is investigation of soil stiffness constants that determines the mount of soil sinkage affected by entered load. Soil sinkage under tires is one of the most important factors of soil compaction. Most of tests for determining parameters of soil constant are done with the assumption that the length of the contact surface of the wheel with soil 1.5 to 2.5 times of the width. Nowadays, the attentions have been directed toward increasing contact area through increasing tire width to reduce pressure on the soil surface. So length and width of tire contact surface with soil are close to each other and tends to become square shape. The test were conducted to determine the amount of soil sinkage by increasing the length and width contact surface by using larger plates to reached length to width ratio revising 1 to 1.5in Soil Bin area. Also the soil constant parameters was measured. Bekker’s pressure – sinkage equation was used in performing calculations and surveys conducted. The results show that in tested relatively dry loamy soil, by increasing contact surface it had large reduction in entered pressure and consequently large reduction of sinkage of soil. These beneficial changes were more striking than the previous studies that is may be related to the square form of the contact surface. Cohesive modulus of soil deformation (Kc) and frictional modulus of soil deformation (K?) and also constant n were achieved respectively n=1.19, K?=2277 and Kc=679.