Based　on　the　three-dimensional　hydraulic　head　distribution　model　and　the　upper　bound　theorem　of　the　limit　analysis,　a　new　model　was　established　to　calculate　the　limit　support　pressure　in　shield　tunnel　faces.　A　series　of　numerical　simulations　were　conducted　to　evaluate　the　accuracy　of　the　proposed　model　and　the　obtained　results　were　compared　with　those　of　other　classical　analytical　methods.　It　is　found　that　the　obtained　analytical　solutions　are　in　good　agreement　with　the　numerical　simulations　and　the　proposed　method　outperforms　other　methods　in　terms　of　accuracy.　In　the　present　study,　the　influence　of　the　water　level,　internal　friction　angle,　burial　depth,　and　water　pressure　on　the　stability　of　the　tunnel　face　is　analyzed.　The　performed　analyses　reveal　that　the　limit　support　pressure　is　negatively　correlated　with　the　internal　friction　angle,　while　the　burial　depth　does　not　affect　the　limit　support　pressure　of　the　shield　tunnel　face　in　subsea　tunnels　(C/D　＞=　1).　Meanwhile,　it　is　found　that　as　the　water　level　and　the　water　pressure　on　the　tunnel　face　increase,　the　limit　support　pressure　increases　linearly,　and　the　failure　area　extends　to　the　front　of　the　tunnel　face　and　decreases　in　height.