Based　on　the　nonlinear　failure　criterion　and　modified　tangential　technique,　the　upper　bound　solutions　of　the　critical　supporting　pressure　on　the　deep　tunnel　face　were　obtained　under　pore　water　pressure　conditions.　The　influence　of　parameters　on　the　critical　supporting　pressure　and　collapse　range　was　investigated　according　to　the　unlimited　block　failure　mechanism.　It　was　found　that　the　upper　bound　solutions　of　the　critical　supporting　pressure　increase　with　the　growth　of　the　nonlinear　coefficient　and　pore　water　pressure　coefficient.　The　collapse　range　of　the　tunnel　face　scales　out　with　the　increase　in　the　nonlinear　coefficient　and　shrinks　with　an　increasing　pore　water　pressure　coefficient.　Moreover,　with　the　increase　in　the　nonlinear　coefficient,　the　impact　strength　on　critical　supporting　pressure　and　collapse　range　declines　gradually.　According　to　the　calculated　results,　both　the　pore　water　pressure　and　nonlinear　criterion　factors　have　negative　impacts　on　the　stability　of　the　tunnel　face.　Thus,　more　attention　should　be　paid　to　these　parameters　to　ensure　face　stability　in　deep　tunnel　construction.