Evaluation Of Stability And Reinforcement Of Slopes And Foundations Of The 150 KV SUTT CCPP-1 AMNT Sumbawa Tower (Case Study: Tower Point 27)

Rosyidah, Ziyadatur (2026) Evaluation Of Stability And Reinforcement Of Slopes And Foundations Of The 150 KV SUTT CCPP-1 AMNT Sumbawa Tower (Case Study: Tower Point 27). Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Ketidakstabilan lereng merupakan permasalahan geoteknik yang dapat mengancam keselamatan infrastruktur, khususnya pada daerah perbukitan. Penelitian ini bertujuan untuk mengevaluasi stabilitas lereng dan kondisi pondasi Tower Saluran Udara Tegangan Tinggi (SUTT) 150 kV pada titik Tower 27 di Sumbawa, Nusa Tenggara Barat, yang mengalami kelongsoran setelah hujan lebat. Lokasi penelitian memiliki topografi curam dengan tanah didominasi oleh lanau (silt) dan lempung (clay) yang diselingi pasir. Metode penelitian meliputi pengumpulan data sekunder (borlog, N-SPT, parameter tanah, topografi, curah hujan, dan beban tower), pemodelan numerik menggunakan coupled program LEM dan FEM, serta analisis stabilitas lereng dengan metode kesetimbangan batas (LEM). Analisis dilakukan pada kondisi sebelum longsor dengan variasi durasi hujan 1 jam, 3 jam, dan 6 jam, serta pada kondisi sesudah longsor untuk mengetahui nilai faktor keamanan (Safety Factor) eksisting. Hasil analisis menunjukkan bahwa faktor penyebab utama kelongsoran adalah infiltrasi air hujan selama 6 jam berturut-turut yang menurunkan nilai SF dari 0,992 (hujan 1 jam) menjadi 0,973 (hujan 6 jam), atau penurunan sebesar 1,92%, sehingga lereng berada pada kondisi kritis (SF < 1,0) dan mengalami longsor. Pada kondisi sesudah longsor, nilai SF berkisar antara 1,595 hingga 2,99, yang mengindikasikan bahwa lereng tidak mengalami keruntuhan total namun masih berada pada kondisi yang relatif stabil.
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Slope instability is a geotechnical problem that can threaten the safety of infrastructure, particularly in hilly areas. This study aims to evaluate the slope stability and foundation condition of the 150 kV High Voltage Overhead Transmission Line (SUTT) tower at Tower Point 27 in Sumbawa, West Nusa Tenggara, which experienced slope failure after heavy rainfall. The study area is characterized by steep topography with subsurface conditions dominated by silt and clay layers interbedded with sand. The research methods included secondary data collection (borehole logs, N-SPT values, soil parameters, topography, rainfall data, and tower loads), numerical modeling using coupled program LEM dan FEM, and slope stability analysis using the Limit Equilibrium Method (LEM). Analyses were performed under pre-failure conditions with rainfall duration variations of 1 hour, 3 hours, and 6 hours, as well as under post-failure conditions to determine the existing Safety Factor (SF) values. The results indicate that the primary cause of the slope failure was rainwater infiltration over a continuous 6-hour duration, which reduced the SF value from 0.992 (1-hour rainfall) to 0.973 (6-hour rainfall), representing a 1.92% decrease, placing the slope in a critical condition (SF < 1.0) and triggering the landslide. Under post-failure conditions, the SF values ranged from 1.595 to 2.99, indicating that the slope did not undergo total collapse but remained in a marginally relative stable.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	stabilitas lereng, kelongsoran, faktor keamanan (SF), SUTT 150 kV, LEM, FEM, infiltrasi hujan, perkuatan lereng, pondasi. slope stability, landslide, safety factor (SF), 150 kV transmission tower, LEM, FEM, rainfall infiltration, slope reinforcemen, foundation.
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA169.5 Failure analysis
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Civil Engineering > 22101-(S2) Master Thesis
Depositing User:	Ziyadatur Rosyidah
Date Deposited:	26 Jul 2026 04:22
Last Modified:	26 Jul 2026 04:22
URI:	http://repository.its.ac.id/id/eprint/137350

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