Two　large-scale　shake　table　experiments　were　conducted　to　study　the　seismic　pile　group-bridge　soil　system　failure　mechanisms　and　examine　the　role　of　soil　crust　in　lateral　spreading　caused　by　liquefaction.　Pile　group-bridge　systems　were　supported　by　two　different　ground　profiles,　inclined　liquefiable　soils　with　and　without　soil　crusts.　The　test　results　are　discussed　in　terms　of　soil　acceleration,　pore　pressure　ratio,　and　displacement　response.　In　addition,　the　pile　seismic　failure　mechanisms　are　depicted　according　to　the　acquired　date,　and　the　effects　of　kinematic　and　inertial　interaction　on　the　curvature　of　pile　and　pier　are　evaluated.　It　was　found　that　during　weak　earthquakes,　the　crust　did　not　have　an　apparent　influence　on　the　system　response.　However,　during　strong　earthquakes,　the　soil　bed　without　crust　experienced　larger　lateral　permanent　displacement　because　the　shallow　soil　showed　dilatant　response　and　triggered　spikes　in　acceleration.　Meanwhile,　the　soil　bed　with　crust　restrained　the　lateral　bridge　displacement.　In　addition,　the　lateral　spreading　caused　by　liquefaction　transferred　the　damaged　position　of　the　pile　group-bridge　system　from　the　pier　bottom　to　the　pile　at　the　bottom　of　liquefied　soil,　while　the　crust　shifted　the　damaged　position　from　the　bottom　of　the　liquefiable　soil　to　the　top　of　pile.　The　results　also　revealed　that　the　crust　weakened　the　kinematic　interaction　on　curvature　at　the　pile　head　but　enhanced　the　inertia　effect　during　the　strong　earthquake,　while　the　opposite　was　true　for　ground　without　crust;　the　kinematic　interaction　was　stronger,　and　the　inertia　interaction　was　diminished.