Protection of Bah Bolon River Cliffs with Geosynthetic Reinforcement on Segmental Concrete Blocks – A Comprehensive Analysis

Riverbed erosion causes landslides and erosion of riverbanks. Landslides that occur on riverbanks are one type of landslide caused by the rapid flow of the river. Retaining wall construction can be built to protect riverbanks from erosion and maintain soil stability. Therefore, the purpose of this study is to plan a riverbank retaining wall that maintains internal and external stability. The method used designing a retaining wall from segmental concrete blocks with geosynthetic reinforcement based on soil data, cliff height, and cliff slope at the riverbank location. This study was conducted in the Bah Bolon River, Simalungun Regency, North Sumatra Province from March 2021 to July 2021. The safety factor of the retaining wall was analyzed, both for internal and external stability. The results of the analysis revealed that the value of the soil friction angle is an important soil parameter in determining the design of retaining walls. The wall safety factor value increases along with the rise of the soil friction angle value. It was determined that Geosynthetic reinforcement is more economical while retaining walls are more stable on soils with higher friction angle values.