Design and behaviour of a geosynthetic reinforced retaining wall and bridge abutment on a yielding foundation

There has recently been an increase in the use of geosynthetic reinforced soil structures to support bridge abutments and approach roads in place of traditional pile supports. In this respect, reinforced soil walls offer a cost effective alternative to, and have been found to reduce the “bridge bump” effect associated with, pile supported abutments. The paper focuses on the numerical analysis of a hypothetical 6 m high geosynthetic reinforced soil wall supporting a bridge abutment and approach road constructed on a 10 m thick yielding clayey soil deposit. The results of the numerical analysis are compared to current design methodologies to examine the effect of the yielding soil foundation on the behaviour of the wall and abutment. The study includes the examination of both the internal and external stability of the wall, and focuses on methods of improving the external stability.