Cantilever retaining walls affected by local corrosion
Load-deformation behaviour
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. Such damages cause a relatively brittle failure caused by rupture of the corroded reinforcing bars. While non-anchored retaining walls were usually dimensioned for active earth pressure only for which a sufficient deformation capacity is presumed implicitly there is much uncertainty regarding the safety of these structures.
By considering potential failure modes of retaining walls and in view of the fact that the load is deformation dependent, 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 with large-scale tests on retaining wall segments and a mechanically consistent model for the load-deformation behaviour of such structures is developed subsequently. The project’s aim is to reliably predict the ultimate load of locally corroded retaining walls in consideration of the deformation dependent earth pressure. The latter is the objective of a simultaneous project carried out by IGT/ETHZ. On this basis, a simplified method, suitable for engineering practice, is developed for the assessment of the structural safety.