A recent pilot study on the condition assessment and conservation of cantilever retaining walls revealed that many of these structures exhibit severe pitting corrosion of the main reinforcement just above the construction joint between footing and wall. As such damages are related to relatively brittle failures caused by rupture of the corroded reinforcing bars, while non-anchored retaining walls were usually dimensioned for active earth pressure only – thus assuming sufficiently large deformations at the ultimate load – there is much uncertainty regarding the safety of these structures
By considering potential failure modes of retaining walls, it can be shown that the load-deformation behaviour of the wall base in the zone affected by local corrosion is decisive for a reliable assessment of the structural safety. However, no suitable models, allowing for a reliable analysis of this behaviour, are available today.
Within the framework of the research project, the behaviour of cantilever retaining walls affected by pitting corrosion of the main reinforcement at their base is investigated experimentally. To this end, tension tests on naked rebars and reinforced concrete tension chords as well as large-scale tests on retaining wall segments are carried out. Based on the test results, a mechanically consistent model for the load-deformation behaviour accounting for pitting corrosion is developed, suitable for analysing the deformation capacity and reliably predicting the ultimate load. On this basis, a simplified method, suitable for engineering practice, is developed for the assessment of the structural safety of existing cantilever retaining walls affected by pitting corrosion.