Research study of the hydraulic behaviour of the Po River embankments

Abstract

To investigate the hydraulic behaviour of the fine-grained embankments along the mid-course of the Po River, research was carried out on a full-scale physical model, built on the floodplain along the existing embankment and forming a pond. The pond was filled to reproduce historical floods. The prototype was built according to recommendations formulated by the Po River Management Authority. The engineering properties of the foundation soils were investigated by in situ tests and complemented by some suction-controlled laboratory tests. Pore-water pressure was measured in the embankment and in its foundation before, during, and after the experimental reproduction of two floods that occurred in 1976 and 2000. Atmospheric variables were monitored at the prototype site. Monitoring data refer to 6 months of experimental activities. Pore-water pressure measurements were first presented and subsequently interpreted through an isothermal two-dimensional flow approach where boundary flow rates express the evolution of atmospheric variables. The distribution of the pore water provided by this interpretation was used for stability analyses of the prototype. Results from the experimental activities and their interpretation indicate that the river embankment remains extensively unsaturated during floods. Typical suction trends within the embankment, suction-associated soil strength, and the resulting slope stability safety factors are also shown.