HUBUNGAN ANTARA KOMPOSISI MINERAL, SIFAT FISIK, REGANGANMENGEMBANG DAN KUAT GESER PADA BATULEMPUNG, FORMASI SUBANG:STUDI KASUS DI DAERAH CISAMPIH, KEC. DAWUAN, KAB. SUBANG,JAWA BARAT

• Main Author: Endah Utami, Tri
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/77078
• Institution: Institut Teknologi Bandung

The objective of this study is to conduct detail assessment of swelling behavior of Subang Formation claystones at the Cisampih area of Dawuan, Subang Regency, West Java. Field observations were conducted to have a better understanding on swelling behavior of the claystones and its impacts. Meanwhile, laboratory tests were carried out to analyze mineralogical composition, physical properties, swelling strains, and shear strength of claystones. The results from XRD and SEM analyses have shown the composition of plagioclase, quartz, montmorillonite, Illite and kaolinite, in claystones with different percentage. Porosity and water content were tend to increase in weathered claystones than in fresh claystones, however unit weight was tend to decrease. Atterberg limits analyses showed that all claystones can be categorized as CH (clay high plasticity). Owing to the surface (< 3 m) and more weathered condition of claystones; volume change due to swelling process tend to decrease. The swelling strains were significantly influenced by the ratio of (montmorillonite + Illite)/kaolinite, and the ratio of clay minerals/non-clay, also the number of montmorillonite + Illite. Swelling strains in the vertical direction were most likely to be higher than in the horizontal direction, therefore it can be inferred that swelling strains of the claystones are anisotropy. The highest volumetic can be identified on sample 6 (15.28 %), followed by 5 (8.23 %), 4 (7.54 %), 3 (3.5 %), 2 (2.49 %) and sample 1 (1.52 %). Result of direct shear tests clearly showed that shear strength were decrease due to swelling strain, with the decrease values of shear strength were ranging from 45 % to 57 %.