In connection with in situ seepage experiments of dikes of the Yangtse River

unsteady seepagethrough dikes was numerically simulated using Plaxis （a commercial geotechnical engineering software） atdifferent tide levels and designed water table. The results showed that seepage through dikes would be es-sentially not influenced by variation in river water table

the calculated safety factors of all measured crosssections were larger than 1. 5

and the simulated water tables of different monitoring points were almostthe same as measured values. Thus conclusions can be drawn that Yangtse River dikes within Nantonghave good seepage stability

and Plaxis proves to be effective for dike seepage safety assessment.