DuringtheconstructionoftheguidingdikeintheYangtzeEstuary,someofthecaissonstructuressankintothesoilfor1～5morslidabout20mawayfromtheoriginalplacewhenastrongstormattackedthisarea.Dynamictriaxialtestswerecarriedouttosimulatethebehavioroffoundationsoilsunderwaveloading.Thetestresultsshowthattheexcessivesettlementandlateralmovementofthecaissonsareduetotheweakeningofthesoftclaystrengthduringthestrongstorm.Thetestresultsalsoshowthattheabilityofthesoftclaytoresistthewaveforcewillbegreatlyincreasedwhenthesoftsoilsamplesaresuitablyimproved.Basedonthetestresults,animprovementmethodcombiningverticaldrainswithsurchargeloadingwasproposedtostrengthenthefoundationsoil.Ontheimprovedsoilfoundation,thedikehasbeenreconstructedandundergoneseveralstrongstormswithoutanydamage.Afiniteelementapproachhasbeendevelopedforanalyzingthesettlementandstabilityofthedikeundertheactionofstrongstorm.
