Briefing: Retaining walls built with scrap tyres

A technique for building gravity retaining walls using scrap tyres is presented. This technique has been used successfully for stabilising natural slopes in Brazil. Experience with a 60 m long, 4 m high soil–tyre retaining wall in Rio de Janeiro is documented. The wall was built in horizontal layers, with scrap tyres tied together with rope or wire and filled with available local soil. Construction was monitored by displacement gauges and pressure cells in four cross-sections with different materials or dimensions for the wall. A 2 m soil surcharge was placed on the backfill, and the displacement responses at the four sections were compared. It is shown that the soil–tyre wall can be considered as an attractive alternative for slope stabilisation, because it combines the mechanical strength of tyres with the low cost of building materials such as local soil and scrap tyres.