The　faults　play　an　important　role　in　inducing　tremendous　potential　threat　to　the　stability　capability　of　embedded　tunnels　in　strong　earthquake　events.　Based　on　the　finite　element　method　with　the　viscous　spring　artificial　boundary,　the　earthquake　motions　of　oblique　incidence　can　be　transformed　into　the　equivalent　nodal　forces　acting　on　the　truncated　boundary　of　finite　element　model.　In　the　present　work,　the　formulas　of　equivalent　nodal　forces　for　the　2-D　plane　P　waves　with　arbitrary　incident　angles　are　deduced　and　implemented　into　the　commercial　software　ABAQUS.　The　accuracy　of　the　formulas　and　the　implementation　are　demonstrated　by　the　numerical　examples　of　a　2-D　semi-infinite　space　and　an　circular　lined　tunnel　in　half-space　subjected　to　obliquely　incident　P　waves.　The　proposed　numerical　method　is　employed　to　investigate　the　non-linear　responses　of　the　tunnels　within　surface　normal　fault　ground　under　obliquely　incident　P　waves.　The　numerical　results　indicate　that　the　tunnels　buried　in　the　hanging　wall,　in　the　foot　wall　and　across　the　fault,　suffer　different　failure　patterns.　The　tunnels　across　the　fault　suffer　the　most　serious　plastic　damage,　followed　by　that　within　the　hanging　wall.　Moreover,　the　seismic　responses　of　the　tunnels　across　the　fault　and　within　the　hanging　wall　increase　with　the　inclination　degree　of　the　incident　P　waves,　as　well　as　opposite　relationship　for　tunnels　within　the　foot　wall.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.