Alternatif Penanganan Settlement Pada Tanah Lunak Studi Kasus: Pembangunan Jalan Patimban Access Toll Road Package 2 Sta. 23+176

Afiffurokhim, Teguh (2026) Alternatif Penanganan Settlement Pada Tanah Lunak Studi Kasus: Pembangunan Jalan Patimban Access Toll Road Package 2 Sta. 23+176. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Penanganan settlement pada tanah lunak merupakan tantangan krusial pada Proyek Pembangunan Jalan Patimban Access Toll Road Package 2 STA. 23+176. Data lapangan lanjutan yang dilakukan oleh kontraktor mengungkapkan kedalaman tanah lunak mencapai 12 meter, dimana pada data tanah tahun 2022 yang digunakan sebagai dasar perencanaan, kedalaman tanah lunak sebesar 5 meter. Kondisi ini menyebabkan desain eksisting (metode soil replacement 2 m dan beban surcharge) menjadi kurang efektif karena membutuhkan waktu hingga 42,80 tahun untuk mencapai derajat konsolidasi 90% (U90), sehingga menghambat target percepatan proyek untuk mencapai pemampatan dalam waktu kurang dari 6 bulan. Penelitian ini bertujuan untuk memprediksi kinerja desain eksisting, mengevaluasi efektivitas berbagai alternatif percepatan konsolidasi (Prefabricated Vertical Drain (PVD) dan Stone Column), serta membandingkan efisiensi biayanya. Metodologi yang digunakan adalah kuantitatif-komparatif melalui pengujian laboratorium primer, data sekunder proyek, analisis manual berdasarkan teori Terzaghi, serta pemodelan numerik Metode Elemen Hingga (FEM) menggunakan perangkat lunak PLAXIS 2D. Hasil penelitian menunjukkan bahwa penggunaan PVD dengan konfigurasi pola segitiga spasi 1,25 m merupakan opsi paling efektif untuk percepatan, dengan pencapaian derajat konsolidasi 92,28% dalam waktu 24 minggu (6 bulan). Metode Stone Column dengan diameter 0,8 m dan jarak spasi 2,25 m mencapai target konsolidasi dalam 26 minggu sekaligus memberikan performa teknis melalui peningkatan kekakuan massa tanah yang mereduksi penurunan total menjadi 0,930 m dan memberikan faktor keamanan tertinggi (SF 1,562). Dari aspek ekonomi, alternatif PVD yang dikombinasikan dengan Prefabricated Horizontal Drain (PHD) merupakan pilihan paling ekonomis dengan estimasi biaya Rp46,7 miliar, jauh lebih efisien dibandingkan desain eksisting (Rp78,9 miliar) maupun metode Stone Column (Rp81 miliar). Penelitian ini menyimpulkan bahwa kombinasi PVD spasi 1,25 m dan PHD adalah solusi geoteknik paling optimal untuk mendukung keberlanjutan proyek tersebut.
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Settlement mitigation in soft soil constitutes a critical challenge in the Patimban Access Toll Road Development Project, Package 2, STA 23+176. Subsequent site investigation conducted by the contractor revealed that the soft soil layer extends to a depth of approximately 12 m, whereas the 2022 subsurface data used as the basis for the original design indicated a soft soil thickness of only 5 m. This discrepancy renders the existing design consisting of 2 m soil replacement combined with surcharge loading ineffective, as it requires up to 42.80 years to achieve 90% degree of consolidation (U90). Such a prolonged consolidation period is incompatible with the project acceleration target, which requires the majority of settlement to occur within less than six months. This study aims to predict the performance of the existing design, evaluate the effectiveness of various consolidation acceleration alternatives—namely Prefabricated Vertical Drains (PVD) and Stone Columns and compare their cost efficiency. A quantitative-comparative methodology was adopted, incorporating primary laboratory test results, secondary project data, manual analytical calculations based on Terzaghi’s consolidation theory, and numerical modeling using the Finite Element Method (FEM) implemented in PLAXIS 2D. The results indicate that the application of PVDs arranged in a triangular pattern with a spacing of 1.25 m is the most effective solution for consolidation acceleration, achieving a degree of consolidation of 92.28% within 24 weeks (6 months). The Stone Column method, with a column diameter of 0.8 m and spacing of 2.25 m, achieved the target consolidation within 26 weeks while also providing superior mechanical performance by increasing the composite soil stiffness. This resulted in a reduction of total settlement to 0.930 m and yielded the highest factor of safety (SF = 1.562). From an economic perspective, the PVD alternative combined with Prefabricated Horizontal Drains (PHD) proved to be the most cost-efficient solution, with an estimated cost of IDR 46.7 billion significantly lower than the existing design (IDR 78.9 billion) and the Stone Column method (IDR 81 billion). It can be concluded that the combination of PVDs with 1.25 m spacing and PHDs represents the most optimal geotechnical solution to support the sustainability and accelerated completion of the project.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Tanah Lunak, Settlement, Konsolidasi, Perbaikan Tanah, Plaxis 2D Soft Soil, Settlement, Consolidation, Ground Improvement, PVD, Stone Column, PLAXIS 2D
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA455.S6 Soil (Materials of engineering and construction) T Technology > TA Engineering (General). Civil engineering (General) > TA749 Soil stabilization
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Civil Engineering > 22101-(S2) Master Thesis
Depositing User:	Teguh Afiffurokhim
Date Deposited:	26 Jan 2026 06:34
Last Modified:	26 Jan 2026 06:34
URI:	http://repository.its.ac.id/id/eprint/130337

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