Analisis stabilitas lereng timbunan dengan perkuatan dinding penahan tanah kantilever menggunakan program plaxis 8.6

Abstract

In 2021, the Yogyakarta Special Region Government through the Yogyakarta Special Region Public Works, Housing and Energy Mineral Resources Office carried out the construction of the Tawang-Ngalang road section which is an access road connecting Sleman Regency with Gunungkidul Regency as an effort to unravel the traffic density that has the potential to cause congestion. This research will analyse the stability of the existing slope and the slope reinforced with a cantilever retaining wall on the Tawang-Ngalang road section located in Ngalang Village, Gedangsari Subdistrict, Gunungkidul Regency segment V Sta 8+400 to determine the potential collapse that occurs on the slope. The methods used in this research are manual calculation analysis with Fellenius method on the existing slope, analysis with Plaxis 8.6 software program on the existing slope and slope reinforced cantilever retaining wall, and manual calculation with Rankine method to calculate stability against overturning, shifting, and soil bearing capacity against collapse on the slope reinforced cantilever retaining wall. The purpose of the analysis is to determine the safety factor, as well as the settlement that occurs on the original slope and the slope reinforced by the cantilever retaining wall. The results of the analysis using the Plaxis 8.6 programme on the original slope obtained a safe number (SF) value without earthquake load of 1,0970 and with earthquake load of 0,9348. While the results of manual calculation of the Fellenius method obtained SF value without earthquake load of 1,0427. For slopes reinforced with cantilever retaining walls, the SF value without earthquake load is 1,4702 and with earthquake load is 1,4694. For the decrease in the original slope without earthquake load, it was obtained at 0,01191 m and with earthquake load of 0,01575 m. Then the slope reinforced cantilever retaining wall without earthquake load is 0,00695 m and with earthquake load of 0,0958 m.