Pengaruh Proses Pelapukan Clay Shale terhadap Perubahan Parameter Rasio Disintegritas (DR)

Idrus M Alatas, Pintor T Simatupang

Abstract


Abstrak

Penelitian ini dilatarbelakangi oleh sering terjadinya kegagalan desain geoteknik pada clay shale yang disebabkan oleh pelapukan. Rasio disintegritas adalah perbandingan perubahan fisik akibat pelapukan pada waktu tertentu terhadap kondisi awalnya. Perubahan sifat fisik clay shale akibat pelapukan ditentukan dengan rasio disintegritas (DR). Pelapukan clay shale akan lebih cepat terjadi akibat siklus pembasahan dan pengeringan bila dibandingkan dengan proses pengeringan. Manakala akibat bertambah jumlah pembasahan dan pengeringan pada waktu yang sama, menyebabkan pelapukan pada clay shale akan lebih cepat lagi. Sampai hari ke-80 dari waktu pengeringan, DR clay shale Semarang-Bawen dan Hambalang besarnya adalah sama yaitu DR = 0,916 (completelly durable). Sedangkan akibat siklus pembasahan dan pengeringan di hari ke-32, clay shale Semarang-Bawen DR = 0,000 atau completelly non durable, manakala pada clay shale Hambalang DR = antara 0,2117 hingga 0,3344. Pada umumnya clay shale Semarang-Bawen akan lebih lebih cepat melapuk bila dibandingkan clay shale Hambalang. Ini terjadi karena perbedaan kandungan mineralogi. Clay shale Semarang-Bawen didominasi oleh mineral Smectite, sedangkan clay shale Hambalang didominasi mineral Kaolinite dan Illite.

Abstract

The background of this research because of the frequent occurrence of the failure in the geotechnical design of clay shale caused by weathering. Disintegration ratio is a comparison of physical changes due to weathering at certain times of the initial conditions. Changes in physical properties due to clay shale weathering determined by the disintegration ratio (DR).Clay shale weathering will occur more quickly as a result of wetting and drying cycles when compared with the drying process. While due to the increased number of cycles of wetting at the same time, causing weathering on clay shale will be faster again. Until the 80th day of drying time, the magnitude DRof Semarang-Bawenclay shaleand Hambalang are the same, namely DR = 0.916 (completelly durable). However, due to wetting and drying cycles on day 32, samples of Semarang-Bawenclay shale is DR = 0.000 or non durable completelly, while on Hambalang clay shale in same day DR between 0.2117 to 0.3344. Generally Semarang-Bawen clay shale will be faster weathered than Hambalang clay shale. It is caused by the mineralogy content of Semarang-Bawen clay shale has dominated by Smectite, and Hambalangclay shalehas dominated mineral Kaolinite and Illlite.


Keywords


Rasio disintegritas, clay shale, pelapukan, proses pengeringan, proses pembasahan dan pengeringan

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References


ASTM, D 4644-87, 1987, Standard Test Method for Slake Durability os Shales and Similar Weak Rocks In Annual Book of ASTM Standard.

ASTM, D 422-72, 1972, Standard Method for Particle-Size Analysis of Soils. Annual Book for ASTM Standard.

Erguler, Z.A., Shakoor, A., 2009, Quantification of Fragment Size Distribution of Clay-Bearing Rocks after Slake Durability Testing, Environmental & Engineering Geoscience, Vol. XV, No. 2, May 2009, pp. 81–89.

Gartung, E., 1986, Excavation of The Hard Clays of The Keuper Formation, Proceeding of Symposium Geotechnical Engineering Divission, Seatle, Washington.

Irsyam, M., Jayaputra, A.A., Himawan, A., Kartawiria, A., 2011, Kasus-Kasus Kelongsoran Pada Tanah Clay shale dan Alternatif Penanggulangannya. Proceeding of the 9th Indonesian Society for Geotechnical Engineers Conference and 15th Yearly Scientific Meeting, Jakarta, December 2011.

LEMIGAS, L., 2015, SEM and XRD Report for Semarang-Bawen and Hambalang Clay shale, Jakarta: LEMIGAS.

Sadisun, I.A., Shimada, H., Ichinose, M., and Matsui, K., 2010, Physical DisintegRasion Characterization of Mudrocks Subjected to Slaking Exposure and Immersion Tests, Jurnal Geologi Indonesia, Vol. 5 No. 4 Desember 2010: 219-225.

Shakoor, A., Tej, P.G., 2011, Assessing The Slaking Behaviour of Clay- Bearing Rock, 10th Annual Tecnical Forum Geohazards Impacting Transportation In The Appalachian Region, Columbus Ohio USA.




DOI: http://dx.doi.org/10.5614%2Fjts.2017.24.1.9

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