Volume 24 (2019) Article 7

Geotechnical properties and microstructural characteristics of Northeast Indian peats

by A. Paul and M. Hussain

Published online: 31.03.2019

Summary

Peat is a unique type of soil whose properties vary widely, making it a very poor foundation material for construction purposes. Therefore, before starting any construction on ground that overlies a peat layer, it is essential to understand the properties of the peat. The purpose of this study was to investigate the properties of different peats that occur in Northeast India. Peat samples were collected from four sites located in the states of Assam, Tripura and Manipur. The names of the sites were: National Highway 39 (NH 39), Kalinagar Tea Estate (KTE), Indo-Bangladesh border (IBB) and National Institute of Technology, Manipur (NITM). The upper surfaces of the peat layers studied were 1–2 m below ground level and their average thickness was 3–9 m. Field and laboratory investigations were conducted to determine degree of decomposition, together with physicochemical and engineering properties of the peat. Microstructural and thermal analyses were also carried out. We found that high organic matter content and slight peat decomposition increased water retention capacity and acidity while simultaneously reducing specific gravity and bulk density. Furthermore, high organic matter content reduced strength and increased compressibility. Microstructural and thermal analyses helped to elucidate the morphological, mineralogical and thermal decomposition characteristics of the peats, and these results largely supported the outcomes of the field and laboratory tests. Overall, the engineering properties of peat soils from IBB and NITM were inferior to those of the soils from NH39 and KTE.

Citation

Paul, A. & Hussain, M. (2019) Geotechnical properties and microstructural characteristics of Northeast Indian peats. Mires and Peat, 24(07), 1–15. (Online: http://www.mires-and-peat.net/pages/volumes/map24/map2407.php); doi: 10.19189/MaP.2018.BG.376

Reviewers

IMCG and IPS acknowledge the work of the reviewers.