Marine Clay Stabilisation using an Encased Stone Column Filled With Tyre Chips as Aggregates-Paper Upload

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The study evaluates whether waste tyre chips can partially replace stone aggregates in geotextile-encased stone columns to improve weak marine clay while reducing tyre-waste disposal. Laboratory model tests compared untreated clay, ordinary stone columns, and encased columns containing different proportions of stone and tyre chips.<br /><br />The model columns were 75 mm in diameter and had a length-to-diameter ratio of 5.33. They were installed in soft clay with an undrained shear strength of about 7 kPa and tested under loading. Non-woven geotextile encasement was used to limit lateral bulging and improve column confinement.<br /><br />Stone columns substantially increased the clay’s load-carrying capacity. The encased all-stone column carried about 2.7 times the untreated clay’s load, compared with about twice the load for an ordinary stone column. Encasing the all-stone column increased its capacity by approximately 38% and reduced bulging and settlement.<br /><br />Tyre-chip replacement lowered performance as the tyre proportion increased, but encased columns with up to 60% tyre chips still had greater load efficiency than the ordinary all-stone column. However, settlement reduction was considered acceptable only up to 40% replacement. The authors therefore recommend replacing up to 40% of the stone aggregate with tyre chips in an encased column, balancing load capacity and settlement performance.<br /><br />The results suggest that geotextile-encased columns can strengthen soft marine clay while enabling beneficial reuse of scrap tyres. These conclusions are based on small-scale model tests.

Keywords

waste tyre chips

geotextile-encased stone columns

soft marine clay

aggregate replacement

load-carrying capacity

undrained shear strength

lateral bulging

settlement reduction

scrap tyres reuse

laboratory model tests