Experimental and Numerical Study of Micropiles to Reinforce High Railway Embankments
Publication: International Journal of Geomechanics
Volume 13, Issue 6
Abstract
The construction of railway embankments on loose beds using reinforcing elements results in a modification of the embankments slope, which significantly reduces the amount of earthworks. In addition, reinforcement of both bed and embankment is essential to increase the load-bearing capacity and control the settlements. A solution for high railway-embankment stabilization and enhancing the operational axle load is the use of micropiles in the embankment toe to transmit the applied loads to the firm underlying layers and avoid the deep sliding of loose subgrade. This paper presents three experimental models of embankments of 10 m in height on a scale of to set up a number of loading tests: one based on a non-reinforced embankment and two others based on reinforced embankments that are stabilized with two different arrangements of micropiles. During laboratory tests, the data, including the load-bearing capacity of embankments, displacements of embankment crest and bed surface, and axial strain of micropiles were measured using the instrumentation tools. In the next step, three numerical models were developed by using the PLAXIS-3D code based on the FEM. Then, a comparison was made between the experimental and numerical data to verify the outputs of the numerical analyses. In the procedure of numerical analyses, elastoplastic behaviors of embankment material and bed were defined based on the Mohr-Coulomb failure criterion, and micropiles were considered as linear elastic elements. Finally, after accomplishing a series of sensitivity analyses on the geometric parameters of micropiles, their efficiency factor was classified in the process of arrangement optimization.
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Information & Authors
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Published In
International Journal of Geomechanics
Volume 13 • Issue 6 • December 2013
Pages: 729 - 744
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Mar 23, 2012
Accepted: Dec 14, 2012
Published online: Dec 17, 2012
Published in print: Dec 1, 2013
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