Investigations on Existing Concrete Cantilever Walls Subjected to Reinforcement Corrosion

Recently fatal collapses of reinforced cantilever walls occurred in the
Alpine Region. Investigations on the collapsed walls showed that these constructions
suffered from corrosion damage along the horizontal construction
joint between the foundation and the vertical concrete wall, which is also the
most sensitive region with respect to stresses. The detection of corrosion is a
difficult task, since the critical areas are not easy to access, because they are
situated on the backfill side of the structure and detection of corroded reinforcement
elements is still a very challenging task.
This paper deals with a numerical sensitivity study based on finite element
analysis (FEA) of existing cantilever walls with the objective to identify reliable
detection methods. Different simulations of corrosion scenarios and corrosion
states at the critical construction joint were taken into account.
Furthermore the possibilities of damage detection using non-direct methods
(deformation measurement, inclination and concrete strains for mobile or fix
stationary installed sensors) are evaluated.
It is demonstrated that the possibility of non-direct damage detection is
limited to certain conditions. These structures are very rigid, and have many
influencing factors which makes it difficult to identify certain damages. Further
investigations on damage detection of concrete retaining structures are needed.