Alternatif Penanganan Stabilitas Lereng Galian Pada Bangunan Conduit Bendungan Cabean

Hikmah, Moh.Nur Kholifatur (2026) Alternatif Penanganan Stabilitas Lereng Galian Pada Bangunan Conduit Bendungan Cabean. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pekerjaan galian pada bangunan conduit Bendungan Cabean menghasilkan lereng dengan kondisi geometri dan karakteristik tanah yang rentan terhadap kelongsoran. Perubahan tegangan akibat pembongkaran material, keberadaan muka air tanah, serta metode pelaksanaan di lapangan menjadi faktor yang menurunkan kestabilan lereng galian tersebut. Kondisi ini apabila tidak ditangani berpotensi mengganggu keselamatan kerja, memperlambat penyelesaian proyek, dan menambah biaya perbaikan di kemudian hari. Penelitian ini mengevaluasi kondisi stabilitas lereng galian eksisting pada tiga potongan kritis pada Conduit (CD) yaitu pada Potongan 10 CD 2, Potongan 11 CD 6, dan Potongan 14 CD 12, dengan meninjau kondisi Muka Air Banjir (MAB), Muka Air Normal (MAN), serta kondisi hujan pada area bukan tampungan. Analisis dilakukan menggunakan metode elemen hingga dengan perangkat lunak Plaxis 2D, pada kondisi statis (tanpa gempa) maupun dengan beban gempa, mengacu pada SNI 8460:2017 dengan kriteria faktor keamanan minimum sebesar 1,5 untuk kondisi normal dan 1,1 untuk kondisi gempa. Tiga alternatif penanganan disimulasikan dan dibandingkan, yaitu Alternatif 1 (shotcrete + wiremesh), Alternatif 2 (soil nailing + shotcrete + wiremesh), dan Alternatif 3 (geogrid + geotekstil). Hasil analisis menunjukkan nilai faktor keamanan (FS) awal rata-rata pada kondisi normal yaitu 1,208, yang belum memenuhi syarat minimum 1,5. Dari ketiga alternatif yang diuji, Alternatif 1 mendapatkan FS akhir rata-rata sebesar 1.347 dengan peningkatan 11% masih belum memenuhi syarat. Kemudian untuk Alternatif 2 memberikan peningkatan FS rata-rata paling besar, yaitu 34% , dengan nilai FS rata-rata akhir mencapai 1.605 sehingga seluruh potongan kritis dinyatakan memenuhi syarat keamanan minimum untuk kondisi normal. Alternatif 3 menghasilkan kenaikan FS sebesar 26% dengan FS rata-rata sebesar 1.51 . Pada kondisi dengan beban gempa, nilai FS awal rata-rata menurun menjadi 0.981, yang juga belum memenuhi syarat minimum 1,1. Setelah diberi penanganan, Alternatif 1 hanya mendapatkan FS akhir rata-rata sebesar 1.042 dengan peningkatan 6.4% dan masih belum memenuhi syarat. Untuk Alternatif 2 menghasilkan FS akhir rata-rata sebesar 1.2 dengan peningkatan 23% dan Alternatif 3 menghasilkan FS akhir rata-rata sebesar 1.174 dengan peningkatan 20% sehingga kedua alternatif tersebut telah memenuhi kriteria keamanan minimum untuk kondisi normal dan kondisi gempa.
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The excavation work on the conduit building of the Cabean Dam produces slopes with geometric conditions and soil characteristics that are susceptible to landslides. Stress changes due to material removal, the presence of groundwater levels, and field implementation methods are factors that reduce the stability of the excavated slopes. If not addressed, this condition has the potential to compromise work safety, delay project completion, and increase future remediation costs. This study evaluates the stability conditions of the existing excavated slopes at three critical sections, namely Section 10 CD 2, Section 11 CD 6, and Section 14 CD 12, by reviewing the conditions of the Flood Water Level (FWL), Normal Water Level (NWL), and rainfall conditions in non-storage areas. The analysis was conducted using the finite element method with Plaxis 2D software, under static conditions (without earthquake) and with seismic loading, referring to SNI 8460:2017 with minimum safety factor criteria of 1.5 for normal conditions and 1.1 for earthquake conditions. Three alternative remediation measures were simulated and compared, namely Alternative 1 (shotcrete + wiremesh), Alternative 2 (soil nailing + shotcrete + wiremesh), and Alternative 3 (geogrid + geotextile). The analysis results show that the initial average factor of safety (FS) under normal conditions was 1.208, which did not meet the minimum requirement of 1.5. Among the three alternatives tested, Alternative 1 achieved a final average FS of 1.3476, representing an 11% increase, but it still did not meet the requirement. Alternative 2 provided the greatest average FS increase, at 34%, with a final average FS of 1.605, meaning that all critical cross-sections were declared to meet the minimum safety requirements for normal conditions. Alternative 3 resulted in a 26% FS increase, with an average FS of 1.51.Under seismic loading conditions, the initial average FS decreased to 0.981, which also did not meet the minimum requirement of 1.1. After treatment, Alternative 1 only achieved a final average FS of 1.042, with a 6.4% increase, and still did not meet the requirement. Alternative 2 produced a final average FS of 1.2, with a 23% increase, while Alternative 3 produced a final average FS of 1.174, with a 20% increase. Therefore, both alternatives have met the minimum safety criteria for normal conditions and seismic conditions.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Stabilitas Lereng, Galian Conduit Bendungan,Shortcrete, Soil Nailing, Geogrid, Faktor Keamanan, Plaxis 2D, SNI 8460:2017. =========================================================== Slope Stability, Conduit Excavation of Dam, Shotcrete, Soil Nailing, Geogrid, Safety Factor, Plaxis 2D, SNI 8460:2017
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA169.5 Failure analysis T Technology > TA Engineering (General). Civil engineering (General) > TA749 Soil stabilization
Divisions:	Faculty of Vocational > 22301-Civil Infrastructure Engineering (D4)
Depositing User:	Moh.Nur Kholifatur Hikmah
Date Deposited:	22 Oct 2026 06:10
Last Modified:	22 Oct 2026 06:10
URI:	http://repository.its.ac.id/id/eprint/145713

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