A statistical analysis on concrete cut-off wall behaviour

Concrete cut-off walls are a well-established technique for forming seepage cut-off in pervious and compressible foundations in newly constructed dams. This study investigated the behaviour of cut-off walls on the basis of statistical analysis. A set of monitoring records and construction details of 43 case histories of in-service concrete cut-off wall constructed in the past 50 years were gathered. Detailed statistical analyses of horizontal displacement, crest settlement, cracking behaviour and stress of the walls were performed based on the case histories. Loading characteristics and relative settlement between the wall and the alluvium foundation were analysed. The statistical analyses also attempted to identify quantitatively the major factors affecting the wall behaviour; these factors include wall location, wall material, foundation deformation characteristics, wall depth and valley shape. The wall location was found to be the deterministic factor that affects the wall behaviour. The findings and results of this study provide a significant insight into concrete cut-off wall behaviour and provide a valuable reference for future wall design and construction.