Studi Perilaku Kuat Geser Tanah Ekspansif Modifikasi Terstabilisasi Bakteri Bacillus Subtilis

Abstract

Changes in the water content of expansive clay soil can cause it to expand and shrink, especially when the seasons shift from wet to dry. During the dry season, these alterations result in shrinkage, and during the wet season, volumetric expansion. When making expansive soil from modified native soil, bentonite, a kind of clay that contains montmorillonite minerals, is utilized as a mixing ingredient because of its notable swelling and shrinking characteristics. Stabilizing expansive soil with bacteria has been shown to be an effective method of improving its mechanical properties, especially its shear strength metrics, since it has a poor bearing capacity and shear strength.

In order to create expansive soil in a lab setting, this study combined bentonite with native soil, which was composed of low-plasticity silt, in a proportion of 70% bentonite to 30% native soil. Bacillus subtilis bacteria were then used to stabilize the expanding soil. A 3-day bacterial culture with different concentrations of 6% and 8%, as well as curing times of 7, 14, and 28 days, were used in a number of experiments.

In comparison to both native and modified soils, the results show that the application of a 3-day bacterial culture considerably increased the soil's cohesiveness and shear strength. Even though the internal friction angle decreased, the soil's total bearing capacity was improved due to the notable improvement in cohesiveness. This study demonstrates that bacterial stabilization is a successful strategy for overcoming expansive soil's drawbacks, especially when it comes to increasing its bearing capacity.