Improvement in Bearing Capacity of Clayey and Sandy Soil Using Geotextile and Terrasil

It is an established fact that weak soils cause damage to structures including road pavement. Stabilization of soil is done to avoid these damages and improve strength, it also helps in improving compaction characteristics of soil. This research examined the basic engineering and geotechnical properties of poor subgrade soil using woven Geotextile and nanochemical (Terrasil) to improve its strength. This is considered to be of great importance in civil engineering works. Subgrade soil on which the load of the pavement rest on is essential to design of pavement structures. Experiments were carried out to investigate the application of Terrasil and inclusion of Geotextile on collected sample A (claysoil) and Sample B (sandy soil) under un-soaked conditions. Geotechnical test was conducted on the samples to determine natural moisture content, grain size analysis, Atterberg limit test, compaction and California bearing ratio test. CBR test were carried out by adding the Terrasil at varying proportion (2 %, 4 %, 6 %, 8 %) and geotextile placement of 2/5 layer, 3/5layer and 4/5 layer of the compacted soil under the un-soaked conditions to determine the strength of the soil. The result shows that the addition of terrasil with geotextile increases the strength of soil and CBR value from 14 % for clay and 26 % at control for both clay and sandy soil samples respectively. At 4 % terrasil dosage and 2/5 layer of geotextile placement distances from the base recorded the highest number of CBR values which are 22 % and 36 % of clay and sand respectively. The difference in the behavior of the soil under un-soaked conditions improved on increasing the percentage at 4 % dosage of Terrasil with 2/5layer horizontal placement of terrasil.