On the influence of the hysteretic behavior of the capillary pressure on the wave propagation in partially saturated soils

摘要

Itiswellknownthatthecapillarypressurecurveofpartiallysaturatedsoilsexhibitsahysteresis.Forthesamedegreeofsaturationithasdifferentvaluesdependingontheinitialstateofthesoil,thusfordryingofawetsoilorwettingofadrysoil.Theinfluenceofthesedifferentvaluesofthecapillarypressureonthepropagationofsoundwavesisstudiedbyuseofalinearhyperbolicmodel.Evenifthemodeldoesnotcontainahysteresisoperator,theeffectofhysteresisinthecapillarypressurecurveisaccountedfor.Inordertoobtainthelimitsofphasespeedsandattenuationsforthetwoprocessesthecorrespondentvaluesformaindryingandmainwettingareinsertedintothemodelseparately.Thisisdonefortwoexamplesofsoils,namelyforDelMontesandandforasiltloambothfilledbyanair-watermixture.Thewaveanalysisrevealsfourwaves:onetransversalwaveandthreelongitudinalwaves.Thewaveswhicharedrivenbytheimmiscibleporefluidsareinfluencedbythehysteresisinthecapillarypressurecurvewhilethewaveswhicharemainlydrivenbythesolidarenot...