DIRECT SHEAR TESTS ON ROOTED SOIL OF DISTICHLIS SPICATA AND KIKUYUOCHLOA CLANDESTINA
Keywords:
Direct shear test, Shear strength, Perennial crops, Root architecture, Root area ratioAbstract
The riverbank areas of the Arequipa region are periodically subject to landslides caused by seismic activity, natural changes in land structure, and climate-related factors. These events have significant social and economic impacts on the local population. Therefore, it is crucial to explore sustainable, efficient, and cost-effective methods for stabilizing slopes. One such method involves enhancing slope stability by increasing the shear strength of the soil through unconventional means. This study examines how adding roots from two perennial crops affects the shear strength of silty sand soils near a riverbank in Arequipa City. The study specifically focuses on Distichlis spicata and Kikuyuochloa clandestine crops, which have extensive root systems developed through stolons. Physical characterization tests were carried out on two samples of silty sand along with direct shear tests using different values of root area ratio at various depths to assess soil-root interaction parameters comprehensively. The test results indicate that both Distichlis spicata crop and Kikuyuochloa clandestina crop alter the soil's shear strength by increasing the friction angle. The modification of cohesion depends on the specific type of crop as well as soil characteristics. Thus, both crops decrease cohesion in one type of soil and increase it in the other one. It can be concluded that integrating these crops into soils significantly enhances their maximum shear stress under elevated normal stresses, thus improving slope stability overall.