UNDRAINED SHEAR STRENGTH PREDICTION AND STABILITY ANALYSIS OF GEOCOMPOSITE REINFORCED EMBANKMENT WITH CLAYEY BACKFILL

摘要

A method of predicting undrained shear strength (Su) within a dual function geocomposite reinforced embankment with clayey backfill is described, in which the effects of discharge capacity (Qw) of the geocompoiste,spacing (2B) between geocomposite layers, construction speed (V), and the coefficient of consolidation (Cv) of the backfill are considered. Then Qw values of three geocomposites were measured by laboratory tests under the confinement of clayey soils. The test results indicate that to maintain a higher long-term (more than 1 month) confined in clayey soil Qw value, a geocomposite must have a drainage core or tube. Then by referring the measured Qw values,the effects of Qw, 2B, as well as V on Su distribution within an assumed 5 m high embankment were investigated by the proposed method. With the predicted Su values, the factor of safety (FS) of the assumed embankment has been investigated by Bishop's slip circle method, and the results demonstrate that a 5 m high embankment with clayey backfill can be successfully constructed using dual function geocomposite.