Electronic Theses and Dissertation

Peristiwa banjir bandang di Kabupaten Bireuen pada akhir November 2025 menghasilkan endapan material yang berpotensi dimanfaatkan untuk bahan konstruksi. Penelitian ini dilakukan untuk mengidentifikasi sifat fisis tanah serta menentukan nilai Optimum Moisture Content (OMC) dan Maximum Dry Density (MDD). Sampel tanah terganggu diambil dari enam titik yang tersebar di tiga kecamatan (Pante Baro Kumbang, Keureumbok, Lueng Daneuen, Cot Ara, Meunasah Pulo, dan Gampong Garot). Pengujian laboratorium mencakup uji kadar air, berat jenis, batas Atterberg, analisis saringan dan hidrometer, serta pemadatan Standard Proctor (ASTM D698). Hasil analisis klasifikasi menunjukkan bahwa berdasarkan sistem USCS, lima sampel dikategorikan sebagai OH dan satu sampel sebagai CL. Sementara itu, menurut sistem AASHTO, sampel tanah terbagi ke dalam kelompok A-7-5, dan A-7-6. Nilai OMC yang didapat berada pada rentang 21,38%–28,47%, sedangkan nilai MDD berkisar antara 1,29–1,52 gr/cm³. Nilai MDD tertinggi (1,52 gr/cm³) dengan OMC (22,59%) tercatat di Desa Gampong Garot, sebaliknya Pante Baro Kumbang mencatatkan MDD terendah (1,29 gr/cm³) dengan OMC (28,38%). Variasi nilai ini mengindikasikan bahwa perilaku pemadatan tiap endapan sangat dipengaruhi oleh plastisitas dan distribusi ukuran butiran. Temuan ini diharapkan mampu menyajikan data teknis terkait kelayakan material endapan banjir sebagai bahan timbunan atau lapisan dasar konstruksi.
Kata kunci: banjir bandang, tanah endapan, sifat fisis tanah, klasifikasi tanah, uji pemadatan, Standard Proctor, OMC, MDD.

The flash flood that occurred in Bireuen Regency at the end of November 2025 deposited sediment materials with the potential to be utilized as construction materials. This study was conducted to identify the physical properties of the deposited soil and to determine its Optimum Moisture Content (OMC) and Maximum Dry Density (MDD). Disturbed soil samples were collected from six locations across three sub-districts, namely Pante Baro Kumbang, Keureumbok, Lueng Daneuen, Cot Ara, Meunasah Pulo, and Gampong Garot. Laboratory testing included moisture content, specific gravity, Atterberg limits, sieve and hydrometer analyses, as well as the Standard Proctor compaction test (ASTM D698). The classification results showed that, according to the Unified Soil Classification System (USCS), five samples were classified as OH and one sample as CL. Based on the AASHTO classification system, the soil samples were categorized into groups A-7-5 and A-7-6. The obtained OMC values ranged from 21.38% to 28.47%, while the MDD values ranged from 1.29 to 1.52 g/cm³. The highest MDD (1.52 g/cm³) with an OMC of 22.59% was recorded in Gampong Garot Village, whereas Pante Baro Kumbang exhibited the lowest MDD (1.29 g/cm³) with an OMC of 28.38%. These variations indicate that the compaction behavior of each sediment deposit is strongly influenced by soil plasticity and particle size distribution. The findings are expected to provide technical data regarding the feasibility of utilizing flash flood sediment as embankment fill or subgrade material for construction purposes. Keywords: flash flood, sediment soil, physical properties of soil, soil classification, compaction test, Standard Proctor, Optimum Moisture Content (OMC), Maximum Dry Density (MDD).