Excavations for a new service installation in Lindsay Road, Edinburgh revealed that the stainless steel reinforcements of the supporting reinforced earth retaining wall were, in parts, severely corroded. This paper summarises the findings of an investigation into the cause of the deterioration of the reinforcement.
A retaining wall was constructed between December 1972 and May 1973 as part of the A901 road improvement at Granton in Edinburgh. The wall carries Lindsay Road while Marine Boulevard runs along the front of the wall (Figure 1). The wall is curved in plan and of maximum height 6.3m above ground level, including a 0.6m deep capping beam. The maximum height above the foundation level is 7.2m, including the capping beam. The wall was built using Vidal's patented ‘Reinforced Earth’ system (e.g., Vidal, 1978). It is believed to be the first such structure built in the UK; according to Price (1975) it was designed and constructed in accordance with the, then, current French Ministry of Transport specification. In February 1999 excavations for new services on Lindsay Road led to reinforcements being exposed along a 50m length of the wall at 4.6m to 5.1m from the front of the wall face. Some sections of the reinforcements were severely corroded and the owner of the wall (The City of Edinburgh Council) was duly notified. The Transport Research Laboratory was commissioned by The City of Edinburgh Council to investigate the cause of the degradation and also to monitor the alignment of the wall. The investigation comprised physical, chemical and metallurgical tests to determine the properties of the fill and the reinforcements, and the extent and nature of the corrosion, and line and level surveys of the face of the wall. This paper presents a summary of the findings of the investigation.
