Comparison and evaluation of cone index- depth variations for tractor mounted and hand- push cone penetrometer

Cone penetrometers are devices to determine the soil penetration resistance at different depths and the results can be used in many varied applications such as construction, military and agriculture. In this research, cone index– depth measurements of a developed tractor mounted and a hand push (model SP1000) cone penetrometers were compared and evaluated. In both systems, a cantilever beam transducer and a photocell sensor were used to measure the soil resistance and depth, respectively. The penetration tests were conducted on two type soils at two plots. On each plot, 10 points were randomly selected and both systems were tested. The hand push penetrometer data were collected in a digital memory and was given to a computer. However, the results of tractor mounted cone penetrometer were recorded by an x-t recorder. The results of experiments indicated that coefficient of correlation for plowed and stubbly soils were R2 = 0.97 and R2 = 0.96, respectively. Based on t-test results, there was no significant difference between cone indexes for both systems at 5% level of confidence. Therefore, with respect to advantages of tractor mounted cone penetrometer, it is suggested to use in soil strength researches.