Sheetpiles Driven into Canal Banks to Lower Seepage Losses

This research investigates the introduction of curtain walls to canal or river banks in order to assess its effect on the exit hydraulic gradient and uplift force acting on hydraulic structures. A computer model utilising the finite element method was used, and four different shaped canal banks were studied. It was found that the introduction of a curtain wall into the middle of the canal bank had no appreciable effect on reducing the uplift force or exit hydraulic gradient. In comparison, the introduction of an inner edge curtain wall proved to be far more effective, where reductions of up to 23% in uplift force, and a maximum reduction of 52% in exit hydraulic gradient, were obtained. Curtain walls or cores, having permeability that equalled 50% of the canal/river bank permeability, had no appreciable effect on uplift force and exit hydraulic gradient even when placed at the inner edge of the canal. It was found that 2D analysis of seepage is inaccurate in some cases as it underestimates flow, exit hydraulic gradient, and uplift force on hydraulic structures.