ANALISIS EFISIENSI BIAYA PERKUATAN LERENG EKSISTING DARI BETON DIBANDINGKAN DENGAN METODE GEOTEKSTIL (Studi Kasus: Lereng di Desa Sulangai Kecamatan Petang)

Abstract

The slope in Sulangai Village, Petang District has a height of 25 m with sandy silt soil
type. On 01/12/2016, landslides occurred at 2 points, namely the Pura Pucak Mangu
highway, precisely in Angantiga village and at the Kancing Gumi Temple road in
Sulangai village, causing the route to be cut off. The landslide on this main line made
traffic flow completely paralyzed. Slope reinforcement management is important, so the
purpose of this study is to determine the cost of slope reinforcement at the study site when
using the geotextile method and the difference in costs to strengthening existing slopes
from concrete based on slope conditions and the value of safety factor in planning
economical slope reinforcement. Unreinforced slope stability was analyzed using a
simplified bishop's method with the help of GeoStudio software, while the geotextile
reinforced slope stability was analyzed for internal and external safety factors. From the
results of the analysis of the condition of the slope without reinforcement, it produces a
safety factor value of 1.083 and is considered not to meet the requirements for a safety
factor of 1.4. To increase the safety factor, it is planned to strengthen the slope using the
geotextile method, this method can increase the slope safety factor for internal stability
by 0.390 so that the slope safety factor becomes 1.473 while the safety factor for external
stability is 3,000. Geotextile installation configurations, namely segments 1,2 and 3, 10
layers of geotextile Sv 0.5 m, and segments 4 and 5, 5 layers Sv 1.0 m using Mirafi PET
Geotextiles Series products, type PET 100-50 tensile strength 100 kN /m costs IDR
3,728,514,155.78