PREDICTION OF UNDRAINED STRENGTH OF CLAYEY EMBANKMENT REINFORCED BY RD GEOTEXTILE

Abstract

A simple and hand-calculable method has been proposed for estimating the undrained shear strength of reinforce/drainage geotextile (RD-G) reinforced clayey embankment. Comparing with FEM analysis results, it shows that the method slightly over-predicts the pore pressure in clayey backfill with an error of about 5% of the applied load. To predict the undrained shear strength, one of the important parameters is the transmissivity of RD-G (Q_w). Laboratory test rests revealed that Q_w reduced significantly with the increase of confining pressure and the elapsed time in the case of clay confinement. It is suggested that for design, long-term confined in-clay Q_w value under corresponding confining pressure should be used. Finally, the effects of construction speed and Q_w value on the undrained shear strength of clayey backfill were investigated by the proposed method. It has been demonstrated that the method is useful for design RD-G reinforced clayey embankment.