Liquefaction　poses　a　potential　threat　to　the　safety,　serviceability　and　stability　of　shield　tunnels　during　seismic　events.　This　study　investigates　the　seismic　response　of　shield　tunnels　in　liquefiable　soils　employing　a　fully　coupled　dynamic　effective　stress　analysis　model.　The　model　accounts　for　the　nonlinear　mechanical　behavior　of　the　shield　tunnel　structure　and　incorporates　the　advanced　bounding　surface　elastoplastic　PM4Sand　and　PM4Silt　models　integrated　with　Biot　u-p　formulation　to　simulate　the　constitutive　behavior　of　liquefiable　and　non-liquefiable　soil　layers.　The　seismic　performance　of　shield　tunnel-liquefiable　soil　system　is　evaluated　considering　ground　motions　with　different　characteristics　in　the　transverse　direction.　The　numerical　results　reveal　the　significant　effects　of　ground　motion　frequency　content　and　seismic　intensity　on　the　liquefaction　triggering,　the　tunnel　deformation　and　the　internal　forces　of　segmental　joints.　The　soil-structure　dynamic　interaction　and　the　soil　shear　dilatancy　characteristics　greatly　influence　the　generation　of　the　earthquake-induced　excess　pore　water　pressure　and　post-liquefaction　shear　strains.　It　is　observed　that　the　soil　contact　pressures　on　the　left　and　right　springlines　of　the　tunnel　experience　larger　increase　compared　to　the　contact　pressure　on　the　tunnel　crown　and　invert.　This　observation　suggests　that　the　soil　could　cause　racking　deformation　on　both　sides　of　the　tunnel　structure　towards　the　center.　Besides,　the　deformations　and　mechanical　behaviors　of　the　segmental　joints　around　the　tunnel　left　and　right　feet　and　the　right　springline　are　notably　higher　than　at　other　joints　in　the　saturated　deposits.　Furthermore,　it　is　found　that　ground　motion　characterized　by　low-frequency　contents,　amplifies　the　seismic　response　of　the　soil　and　the　tunnel　when　compared　to　the　ground　motions　with　high　or　moderate-frequency　contents.　©　2024　Elsevier　Ltd