Electronic Theses and Dissertation

Formasi Tutut merupakan salah satu formasi pembawa batubara di Provinsi Aceh yang menjadi target kegiatan penambangan di PT Mifa Bersaudara. Aktivitas pengupasan overburden menghasilkan material batulempung dan batupasir yang ditimbun pada disposal area. Meskipun sebagian area disposal telah mengalami pemadatan yang baik, beberapa zona bekas mudcell masih menunjukkan kondisi bawah permukaan yang berpotensi memengaruhi karakteristik geoteknik. Penelitian ini bertujuan untuk mengkaji kondisi geologi serta mengevaluasi hubungan nilai Standard Penetration Test (N-SPT) terhadap parameter kuat geser tanah pada dua lokasi bekas mudcell. Analisis dilakukan melalui pemetaan geologi, pengujian Standard Penetration Test (SPT), pengujian laboratorium, dan analisis regresi linier. Hasil penelitian menunjukkan bahwa daerah penelitian tersusun oleh batulempung, batupasir, dan sisipan batubara Formasi Tutut. Nilai N-SPT berkisar antara 1–52, sedangkan kuat geser tanah berkisar antara 13–73 kPa, yang mengindikasikan variasi kondisi lapisan bawah permukaan dari sangat lepas hingga padat. Beberapa kedalaman masih menunjukkan nilai N-SPT 0–4, yang mengindikasikan material belum mengalami pemadatan secara optimal. Analisis regresi memperlihatkan bahwa nilai N-SPT memiliki hubungan yang sangat kuat dengan parameter geomekanika, khususnya kohesi dan kuat geser tanah, dengan nilai signifikansi 7,56523 × 10⁻¹⁰ dan koefisien determinasi (R²) sebesar 0,93. Hasil penelitian ini menunjukkan bahwa nilai N-SPT dapat digunakan sebagai indikator yang andal dalam mengevaluasi karakteristik bawah permukaan dan mengidentifikasi zona-zona disposal yang masih memerlukan perhatian khusus dalam pengelolaan geoteknik.

The Tutut Formation is one of the major coal-bearing formations in Aceh Province and serves as the primary target for coal mining activities at PT Mifa Bersaudara. Overburden stripping during mining operations generates mudstone and sandstone materials that are subsequently deposited in disposal areas. Although most sections of the disposal area have undergone adequate compaction, several former mudcell zones still exhibit subsurface conditions that may affect their geotechnical characteristics. This study aims to investigate the geological conditions and evaluate the relationship between Standard Penetration Test (SPT) N-values and soil shear strength parameters at two former mudcell locations. The study was conducted through geological mapping, Standard Penetration Test (SPT) investigation, laboratory testing, and linear regression analysis. The results indicate that the study area is composed of mudstone, sandstone, and interbedded coal of the Tutut Formation. The N-SPT values range from 1 to 52, while the soil shear strength ranges from 13 to 73 kPa, indicating variations in subsurface density from very loose to dense conditions. At several depths, N-SPT values of 0–4 were recorded, suggesting that the deposited materials have not yet achieved adequate compaction. Regression analysis demonstrates a very strong relationship between N-SPT values and geomechanical parameters, particularly cohesion and shear strength, with a significance value of 7.56523 × 10⁻¹⁰ and a coefficient of determination (R²) of 0.93. These findings indicate that N-SPT values can serve as a reliable indicator for evaluating subsurface conditions and identifying disposal zones that require further geotechnical assessment and management.