The Study of Interface Shear Strength Between Geotextile and Soil Liner Containing Different Percentage of Sodium Bentonite

Abstract

The purpose of this research is to focus on the interface shear strength between geotextiles and soil with different percentage of sodium bentonite. Firstly, the physical properties of the soil samples must be identified in order to determine the soil classification. The laboratory tests include atterberg limit test, shrinkage limit test, specific gravity test, pH test, sieve analysis test and hydrometer test. The soil samples are natural soil sample, soil added with 0 % of sodium bentonite, soil added with 2.5 % of sodium bentonite, soil added with 5.0 % of sodium bentonite, soil added with 7.5 % of sodium bentonite and soil added with 10 % of sodium bentonite. Based on the test results, the added percentages of sodium bentonite did not appear to have any effect on the properties of the soil samples such as the liquid limit, plastic limit and specific gravity. This is because the values obtained were approximately the same and no apparent changes were detected. However, the shrinkage limit and pH test results shows an increasing trend with the increase of sodium bentonite percentage. The natural soil can be classified as Sandy SILT of Intermediate Plasticity (MI). After classifying the soil samples, compaction tests were performed to get the values of optimum moisture content required during direct shear box test. As with liquid limit plastic limit and specific gravity tests, the results for compaction and direct shear test also did not give good results, as the values of optimum moisture content, cohesion and friction angle were also quite similar to each other. Thus, it can be clearly said that, as an admixture, sodium bentonite did not affect the soil samples, therefore not suitable for this type of soil.