SLOPE STABILITY AND ERODIBILITY OF SOIL ANALYSIS TO SUPPORT CONSTRUCTION PLAN OF EMBUNG IN BANGUNSARI AREA, CIAMIS REGENCY, WEST JAVA

• Main Author: Rizky Ramadhan, Endry
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/69864
• Institution: Institut Teknologi Bandung

Bangunsari area is an area with people who have the main livelihood of farming and gardening. In general, this area will meet water shortages in dry season which will have an impact on irrigation on farming and gardening land. Embung can accommodate water (rain water, water from river, and groundwater) so it can be one of the solutions to solve the problem. The purpose of this study is to conduct slope stability and erodibility of soil analysis at the location of embung construction plan so that embung can survive in a variety of conditions. The research area is located at 7° 25' 56.4159 " S 108° 32' 34.9046" E - 7° 26' 29.3255 " S 108° 32' 07.3185" E and embung construction plan is located at 7° 26' 13.1" S 108° 32' 48.5" E. The research area is above the Tapak Formation which its layer has 10°-18° slope and it is classified as Kuesta Ridge and Homogeneous Ridge geomorphological units. Twelve soil samples were taken at the location of embung construction plan. Soil Classification is conducted based on the Unifed Soil Classification System (USCS) using data from soil characteristics tests. Soil slope stability analysis is conducted using the Limit Equilibrium Method developed by the Bishop based on unit weight, saturated unit weight, friction angle, and soil cohesion. Soil erodibility analysis is conducted using the Wischmeier and Smith Nomograph Method based on data from soil tests, the percentage of soil organic matter, soil structure, and soil permeability. The type of soils at embung constrcution plan location belongs to the group BC (silty sand), SC (clayey sand), and SP SM (poorly graded sand, silty sand) and have moderate to high erodibility with K factor value of 0.26 – 0.39. In general, embung slope to be stable must have a maximum slope angle of 72o - 74o with safety factor value of 1.515 – 1.538 and bank width of 0.56 – 0.66 meters, in order to remain slope stability in all water level conditions of embung, maximum embung slope angle must be provided at 72o. Some solutions that can reduce the erodibility and maintain the slope stability of embung are by installing geomembrane, planting vegetation, and making drainage system.