The　effectiveness　and　reliability　of　joint　connections,　construction　convenience,　and　seismic　safety　are　important　factors　in　the　prefabrication　of　bridge　substructures.　To　facilitate　the　rapid　construction　and　seismic　design　of　prefabricated　bridge　substructures　based　on　an　ultrahigh-performance　concrete　(U　H　P　C)　grouting　material,　a　precast　column-to-foundation　socket　joint　structure　with　convenient　construction　and　high　fault　tolerance　was　developed　in　this　study.　A　pseudo-static　test　of　socket　column-foundation　joints　with　a　1/3　scale　ratio　was　performed　to　explore　the　influence　of　shear　keys　and　section　width　on　the　failure　modes　and　seismic　performance　indices　of　the　joints.　A　refined　finite-element　model　of　the　novel　joint　was　established　using　ABAQUS,　the　stress　distribution　rule　of　the　joint　area　was　investigated,　and　a　method　for　predicting　the　moment　capacity　of　the　socket　joints　was　developed.　The　results　show　that,　when　the　socket　depth　is　not　less　than　80%　of　the　column　width,　the　damage　development　of　the　socket　joint　is　concentrated　at　the　bottom　of　the　column,　and　the　failure　mode　is　the　buckling　fracture　of　the　longitudinal　reinforcement　after　the　concrete　peels　off　the　column,　which　is　a　typical　plastic　hinge　ductile　failure　at　the　bottom　of　the　column.　Simultaneously,　the　foundation　is　in　an　clastic　state,　which　verifies　the　good　seismic　performance　of　the　joints.　Toothed　keys　can　significantly　improve　the　anchorage　capacity　of　the　joint　area　to　the　column;　however,　they　have　no　obvious　impact　on　the　overall　bearing　capacity,　seismic　performance　index,　or　failure　model　of　the　joints.　The　established　numerical　model　can　predict　the　failure　mode　and　nonlinear　hysteretic　behavior　of　socket　joints　more　accurately.　The　accuracy　of　the　proposed　method　for　calculating　the　moment　capacity　of　socket　joints　was　verified　by　experiments　and　numerical　results.　The　results　of　the　study　provide　a　reference　for　socket　joints　in　the　seismic　design　and　application　of　precast　assembled　bridges　in　medium-　and　high-intensity　areas.　©　2023　Xi＇an　Highway　University.　All　rights　reserved.