Torsional vibration of a pipe pile in transversely isotropic saturated soil

Thisstudyconsidersthetorsionalvibrationofapipepileinatransverselyisotropicsaturatedsoillayer.BasedonBiot’sporoelastictheoryandtheconstitutiverelationsofthetransverselyisotropicmedium,thedynamicgoverningequationsoftheouterandinnertransverselyisotropicsaturatedsoillayersarederived.TheLaplacetransformisusedtosolvethegoverningequationsoftheouterandinnersoillayers.Thedynamictorsionalresponseofthepipepileinthefrequencydomainisderivedutilizing1Delastictheoryandthecontinuousconditionsattheinterfacesbetweenthepipepileandthesoils.ThetimedomainsolutionisobtainedbyFourierinversetransform.Aparametricstudyisconductedtodemonstratetheinfluenceoftheanisotropiesoftheouterandinnersoilonthetorsionaldynamicresponseofthepipepile.