Assessing the Impact of Non-Woven Geotextiles on Strengthening Expansive Soil

Abstract

Due to detrimental effects of expansive soil in Jimma, non-woven geotextiles have been proposed as a solution to address the challenges. This research focused on the engineering properties of expansive soil, specifically the impact of reinforcement on compaction, California Bearing Ratio (CBR), and moisture variation within the pavement layer. The average values of Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) for the natural soil were found to be 25.02% and 1.48 g/cm3, respectively. After the reinforcement with non-woven geotextiles, the MDD increased to 1.62 g/cm3, while the OMC remained nearly the same. The soaked CBR of natural soil was determined to be 2.38%, indicating that it was unsuitable as a subgrade material. However, after reinforcement, there was a 12.24% improvement in the CBR, indicating that the geotextiles had a positive impact on the bearing capacity of the soil. This suggests that the strength and thickness of geotextiles contributed to the improved compaction and CBR of the soil. The study also investigated moisture migration within the pavement layer. Non-woven geotextiles were impregnated at various depths, and the moisture levels were measured in each layer. The middle layer had the lowest moisture content among all layers, suggesting that the geotextiles effectively controlled moisture migration. Hence, this study confirms non-woven geotextiles' efficacy against expansive soil by controlling moisture and enhancing structural performance. Overall, non-woven geotextiles prove to be valuable in improving the engineering properties of expansive soil.

Keywords: expansive soil, California Bearing Ratio (CBR), Non-woven Geotextiles, Moisture Variation