Seepage Control of Flood Embankment by Anqing City

The flood embankment by city Anqing is a typicalreach of levees along Yangtze River.Its foundation is strong permeability with deeper sand deposits overburden complicated soil layers of weak permeability.Although 100 more relief wells had constructed at landside toe of the embankment but never attained the presupposed effect due to silting year by year.In this paper the present state and tendency of silting gradually in relief wells is verified by analyzing data of field observation.By experiments in laboratory and field a washing method to restore well relieving effect was found.With FEM the 2-D seepage flow computation for 7 typical sections was conducted.After comparison of effects for different seepage control measures the different strengthening schemes such as overburden layer thickened inside,cut-off sand layers,maintainingdrainage line of original relief wells etc. were proposed individually for different reaches of the embankment.