Shear Strength and Long Term Compressibility of Tropical Peat

SUTEJO, YULINDASARI and GOFAR, NURLY (2013) Shear Strength and Long Term Compressibility of Tropical Peat. In: Proceedings of the 17th Annual Scientific Meeting, Geotechnical Solution in Indonesia to Respond the Challenge of Urban, Industry, Infrastructure and Mining Development, 13-14 Nopember 2013, Borobudur Hotel, Jakarta, Indonesia., 13-14 November 2013, Jakarta.

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    Abstract

    ABSTRACT : Almost 1.5 million hectare (20.60 %) of South Sumatra is covered by peat overlaying soft cohesive soil. Thus, the knowledge on the compression behavior of peat soil is essential for the design of infrastructures in the area. This paper discusses the shear strength and long term compression behavior of peat. The shear strength is assessed by field vane shear test and laboratory direct shear test while the long term compression behavior is analyzed based on data obtained from consolidation test performed in Rowe cell with excess pore water pressure measurement. Study shows that the peat has very low shear strength indicated by low cohesion while the high internal friction angle was derived from the fiber content. Furthermore, the results indicate that the peat has a significant secondary compression stage which is not constant with the logarithmic of time. The secondary compression started as early as 65 % degree of primary consolidation. The consolidation test with pore water pressure measurement using Rowe cell enables the observation of the large deformation and better assessment of the long term compression behavior of fibrous peat. Keywords: peat, shear strength, compression behavior, pore-water pressure measurement ABSTRAK : Hampir 1.5 juta hektar (20.60%) luas propinsi Sumatra Selatan ditutupi oleh tanah gambut di atas tanah lempung lunak. Oleh karena itu pengetahuan mengenai sifat kompresibilitas tanah gambut sangat penting bagi perencanaan infrastruktur di daerah ini. Artikel ini membahas kekuatan geser dan kompresibilitas tanah gambut. Kekuatan geser diukur dengan uji geser baling di lapangan dan uji geser langsung di laboratorium, sedangkan kompresibilitas dianalisis berdasarkan hasil pengujian konsolidasi menggunakan sel Rowe dengan pengukuran tekanan pori. Hasil studi menunjukkan bahwa tanah mempunyai kekuatan geser berupa kohesi yang sangat rendah dan sudut geser dalam yang cukup tingi yang disebabkan oleh serat sehingga tidak dapat diperhitungkan. Kajian juga menunjukkan bahwa tanah gambut jenis ini mempunyai sifat rangkak yang dominan dan tidak linier terhadap waktu. Penyusutan akibat rangkak dimulai seawal 65 % derajat konsolidasi primer. Pengujian dengan menggunakan alat konsolidasi Rowe dengan pengukuran tekanan air pori sangat berguna karena memudahkan dalam memprediksi sifat kompresibilitas tanah gambut dalam jangka waktu lama. Kata Kunci : gambut, kuat geser, sifat kompresibilitas, pengukuran tekanan pori

    Item Type: Conference or Workshop Item (Speech)
    Subjects: T Technology > TA Engineering (General). Civil engineering (General)
    Divisions: Faculty of Engineering > Department of Civil Engineering
    Depositing User: ST., M.Eng. Yulindasari Sutejo
    Date Deposited: 12 Feb 2014 17:32
    Last Modified: 12 Feb 2014 17:32
    URI: http://eprints.unsri.ac.id/id/eprint/3422

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