External stability of reinforced soil walls

The external stability; forward sliding, overturning and rotation stability, of reinforced soil walls was assessed using Eurocode 7 and BS 8006 (1995). Overall Eurocode 7 gave higher utilisation factors than BS 8006 (1995). Eurocode 7 Design Approaches 1 (Combination 2) and 3 were found to be critical, and for the structures analysed, always gave the highest utilisation factors. In sliding, Design Approach 3 required a foundation soil with an increased angle of friction or longer reinforcement to maintain stability. The material factor of 1.25 applied to the tangent of the angle of friction in Design Approaches 1 (Combination 2) and 3 had a significant effect on stability, increasing the utilisation factor. The eccentricity of the resultant vertical load varied significantly, with no agreement between values determined using Eurocode 7 and BS 8006 (1995). The design of walls in German (EBGEO, 2010) and France (NF P94-270, 2009) in accordance with Eurocode 7 was found to be more conservative (higher utilisation factors) than walls designed using BS 8006 (1995).