Embankment Construction with Saturated Clayey Fill Material Using Geocomposites

Abstract

To design an embankment using saturated clayey backfill with a dual function (drainage and reinforcement) geocomposite, predicting the undrained shear strength (S u) of the backfill during construction is an essential requirement. A method of predicting the S u value has been proposed, in which the effects of discharge capacity (Q w) of the geocomposite, spacing (2B) between geocomposite layers, construction speed (V), and the coefficient of consolidation (C v) of the backfill are considered. Then Q w values of four geocomposites were measured by laboratory tests under the confinement of clayey soils. The test results indicate that to maintain a higher long-term (about 1 month) Q w value (> 100 m 3 /year/m), for a geocomposite confined in clayey soil, it must have a drainage core and a strong filter. Finally, example analysis was conducted on predicting S u values and evaluating the factor of safety (FS) of an assumed geocomposite reinforced 5 m height embankment with saturated clayey backfill. A parametric study was carried out to investigate the effects of Q w , 2B, as well as V.