Strength recovery of remolded dredged marine clay: thixotropic hardening vs. induced cementation

Chan, Chee-Ming (2015) Strength recovery of remolded dredged marine clay: thixotropic hardening vs. induced cementation. Electronic Journal of Geotechnical Engineering, 20 . pp. 5847-5858. ISSN 1089-3032

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Official URL: http://www.ejge.com/2015/JourTOC20.13.htm

Abstract

Dredged marine soils, particularly clays and silts, are usually disposed of in open sea, inadvertently causing contamination and destruction of the marine ecosystem. Some of these adverse effects are long term, far-reaching and irreversible. However, if suitably assessed and managed, the dredged soil can be potentially reused as a backfill material with sufficient soundness and safety. Applications include reclamation and shoreline rehabilitation works, where artificial land is created using the dredged soil. Due to the very soft or slurry form of the material, significant subsidence is expected in a backfilled embankment, as the soil undergoes sedimentation and self-weight consolidation. This would be followed by time-dependent regain of strength, under constant water content or volume condition, also known as ‘thixotropic hardening’. It is imperative to know this time-dependent characteristic of the mateial for efficient reuse, where the time required for sufficient strength regain can be estimated. Nonetheless the process can also be hastened with induced cementation. The present study simulates and examines the post-consolidation hardening as well as induced cementation of a couple of dredged marine clay samples, with the aim of shedding light on the the ageing effect and induced solidification contributing to long term strength gain. The samples were retrieved from Malaysian waters, and remoulded (with or without solidification) in the laborotary to form simulated backfilled soil beds. Measurements included the vane shear and cone penetration tests. The findings serve as a preliminary guide to the influence of time factor on strength recovery of reclaimed grounds backfilled with dredged marine clay left to settle by itself.

Item Type:Article
Uncontrolled Keywords:dredged marine clay; thixotropy; induced cementation; time; remoulded strength
Subjects:T Technology > TA Engineering (General). Civil engineering (General) > TA703-711 Engineering geology. Rock mechanics. Soil mechanics.
Divisions:Faculty of Engineering Technology > Department of Civil Engineering Technology
ID Code:7419
Deposited By:Normajihan Abd. Rahman
Deposited On:02 Feb 2016 16:42
Last Modified:02 Feb 2016 16:42

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