PENGARUH KONDUKTIVITAS HIDROLIK TERHADAP STABILITAS LERENG (STUDI KASUS CITRALAND LAMPUNG)

Abstract

Landslides have been a disaster that has hit Indonesian society for quite a long time. Based on data from the National Disaster Management Agency (BNPB), the percentage of landslides reached 18.85% of the total events in 2019 and ranked fourth. The latest landslide incident occurred on 26th January 2021, at Block A9 of the DaVinci CitraLand Lampung Cluster, thought to be caused by soil softening due to natural waterways and infiltration from the side of the slope. The purpose of this study is to analyze the relationship between ground water level (MAT) with safety factor (FK) and hydraulic conductivity. On the other hand, this study also aims to determine the maximum safe groundwater level and measures to maintain slope stability in the area. Finite element method is used in the analysis using plaxis software. Modeling changes in groundwater level using Plaxis has obtained several conclusions. On a slope with a groundwater depth of -10m from the ground surface the safety factor is 1.42, a groundwater depth of -9m tha safety factor is 1.257, a groundwater depth of -8m the safety factor is 1.163, and a groundwater depth of -7m occurred when the slope Collapseed. Piezometer data in 2023 shows an increase in groundwater level. However, the slopes remain safe, because the average depth of groundwater is at an elevation of -10m from the ground surface, so the safety factor still exceeds the recommended threshold. The study concluded that groundwater levels significantly influence slope stability, with higher levels increasing hydraulic conductivity and landslide risk. To prevent landslides, measures such as monitoring groundwater levels in pump wells and implementing horizontal drainage systems are recommended for environmental sustainability and ease of application