A 2.5D finite/infinite element approach for modelling visco-elastic bodies subjected to moving loads

Theobje ctiveof this study is to proposea 2.5D $nite=in$nite element procedure for dealing with the ground vibrations induced by moving loads. Besides the two in-plane degrees of freedom (DOFs) per node conventionally used for plane strain elements, an extra DOF is introduced to account for the outof- planewavetransmission. Thepro$leof thehalf-spaceis divided into a near $eld and a semi-in$nite far $eld. The near $eld containing loads and irregular structures is simulated by the $nite elements, while the far $eld covering the soils extending to in$nity by the in$nite elements with due account taken of the radiation e>ects for moving loads. Enhanced by the automated mesh expansion procedure proposed previously by the writers, the far $eld impedances for all the lower frequencies are generated repetitively from the mesh created for the highest frequency considered. Finally, the accuracy of the proposed method is veri$ed through comparison with a number of analytical solutions