Class A Prediction of the Behavior of Soft Estuarine Soil Foundation Stabilized by Short Vertical Drains beneath a Rail Track
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 136, Issue 5
Abstract
In Australia, very few rail tracks have been constructed directly on deep estuarine deposits. In recent years, Kooragang Island has become a major export terminal and most coal trains need to cross the main lines at Sandgate to enter Kooragang Island. In this study, a rail track built on up to 30 m of thick soft estuarine soil was stabilized with relatively short vertical drains to consolidate the soil just beneath the track, and no additional preloading surcharge was provided, except the weight from the trains. The initial soil compression was caused by the passage of trains with a speed restricted at 40 km/h. From this study, it is shown that prefabricated vertical drains significantly decrease the buildup of excess pore-water pressure during cyclic loading, and also continue to dissipate excess pore-water pressure during the rest period. A preliminary finite-element analysis was employed to examine the performance of vertical drains, and a Class A prediction was obtained in terms of lateral and vertical displacements. The monitored settlement and lateral displacement results are presented and discussed. The study shows that relatively short vertical drains are sufficient for providing stability for rail tracks, without the need for driving deep vertical drains through the entire soft soil depth.
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Acknowledgments
The writers appreciate the support given by the Australian Rail Track Corporation (ARTC), and John Holland Pty Ltd. The writers thank the CRC for Railway Engineering and Technologies (Australia) for its continuous support. The laboratory research carried out by former and current doctoral students under the guidance of the first writer in the area of cyclic testing of soft clays and vertical drains is gratefully appreciated.
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Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 136 • Issue 5 • May 2010
Pages: 686 - 696
Copyright
© 2010 ASCE.
History
Received: Dec 8, 2008
Accepted: Oct 19, 2009
Published online: Oct 22, 2009
Published in print: May 2010
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