MECHANICAL PROPERTIES OF AN ALFISSOL SUBMITTED TO AGRICULTURAL MACHINERY TRAFFIC IN A SEMIARID REGION IN BRAZIL - DOI: 10.13083/1414-3984.v22n06a05

Resumo

The load carrying capacity of the soil can be determined from preconsolidation curves, being sensitive to the variation of loads and extremely sensitive to changes in soil moisture. For this study, the water content in soil was 2.50% and 10.58% for the layer from 0 to 0.15 m. Soil samples were collected before and after traffic with one and two passes of a tractor weighing 7100 kg, equipped with 14.4-24 R1 bias tires on the front with inflation pressure of 82.74 kPa and 18.9-34 R1 rear tires with inflation pressure of 96.53 kPa, and a tire ground contact area of 0.11 m2 and 0.13 respectively for the front and rear tires. The speed at the time of the pass for each treatment was 2.22 m s-1. Regardless of the soil water content, the load carrying capacity increases with the traffic of machines due to reduction of voids. Preconsolidation curves should be used with caution due to the use of samples for determining the points in saturated conditions, and when recommended for load-bearing capacity, unsaturated samples should be used.