Numerical analysis of geosynthetic reinforced retaining wall constructed on a layered soil foundation

A numerical examination of the behaviour of an 8 in high geosynthetic reinf orced soil wall constructed on a layered foundation stratum is described. T he foundation consists of a 0.8 in hard crust, underlain by 2.95 in of soft loam (sandy/silty) and then 1.3 in of stiff clay. Below the clay is 1.75 i n of fine sand underlain by a layer of clayey/fine sand extending to a dept h below 10 m. The wall was constructed with 16 segmented concrete facing bl ocks, a sandy backfill material with 30% fines and 11 layers of geogrid rei nforcement 6 m long. Five additional, one metre long layers of reinforcemen t were used between the 6 m long layers within the upper 5 m of the wall to improve the local stability of the facing blocks. The analysis examines th e effect of uncertainty regarding the drained and undrained strength of the loam foundation material, its stiffness, the thickness of this soft layer and its position with respect to the bottom of the wall on the calculated b ehaviour and compares the calculated and observed behaviour. (C) 2001 Elsev ier Science Ltd. All rights reserved.