Investigation and Slope Improvement of Landslides on Bodor River Slopes

The Bodor River is an important source of rice irrigation because most of the population works in the agricultural sector. The slopes of the Bodor River have experienced landslides, causing a major negative impact on the community. Many studies state that soil type, consistency, and friction angle influence slope failure. However, the relationship between soil characteristics and landslides on slopes, especially on the Bodor River, has not been studied. This research aims to identify soil characteristics and their influence on landslides on the slopes of the Bodor River, along with recommendations for improvement. The soil was taken after a landslide occurred at a depth of 80 cm for a sieve gradation test, Atterberg limit test, direct shear test, and slope stability analysis using the Cullman method. The research results show that the SW-SM soil type on the slopes of the Bodor River is highly vulnerable to landslides. A steep slope of 50° and a low soil friction angle between 1.38 and 14.11 have less than one safety factor. Changes in soil conditions, such as increased water content, contribute to a higher risk of landslides. Therefore, strengthening the slope is necessary, with the recommendation to increase the slope to 34.5° so that the slope safety factor increases by 73%. The results of this research provide an overview of the relationship between geotechnical soil parameters that influence slope failure in river areas and recommendations for slope improvement to prevent future collapse.