Design and fabrication of a motorized soil extractor for moisture and density test

Abstract

Sand Cone Method is the most commonly used method for the Field Density Test under Soil testing. It is used to determine the moisture content and dry density of the soil in earth fills and embankments. Although this method is commonly used, it is time consuming, has errors due to exposure of soil to evaporation by the sun and injuries due to manual excavation of the hole using a hammer and chisel. Despite all this, there has been nothing done to solve this issue and yet many earth structures are at risk of failure within their lifespan in use. Therefore, this research is about the design, fabrication and testing the performance of a motorized soil extractor that does not expose the soil sample to the sun, reduces drudgery and injuries hence saving time and reducing errors. The difference in moisture content between the samples of sand cone method and the samples of the motorized soil extractor was established to be 2.208% on a very cloudy day. This implied that the difference in the moisture content between these two would have been beyond the maximum acceptable error (2.5%) on a shiny day when evaporation rate is high. In conclusion, the motorized soil extractor doesn’t expose the soil to the sun which eradicates the moisture content errors and saves time unlike the sand cone method. It is therefore recommended that in order for a precise relative compaction to be achieved, a motorized soil extractor is needed to extract soil.