Roof　stability　of　shallow-buried　cylindrical　tunnels　in　rock　strata　following　the　generalized　Hoek-Brown　criterion　(GHB)　is　analyzed　in　this　work.　Based　on　the　limit　analysis　method,　a　three-dimensional　(3D)　shallow-buried　collapse　mechanism　for　tunnel　roofs　is　developed　to　derive　various　stability　measures.　Optimization　codes　are　programmed　to　capture　the　optimal　stability　measure　solutions.　The　effects　of　the　3D　geometric　characteristics,　the　rock　mass　strength　parameters,　and　the　buried　depth　on　tunnel　roof　stability　are　investigated　by　a　parametric　analysis.　The　critical　buried　depth　ratios　corresponding　to　the　transition　between　the　shallow-buried　and　deep-　buried　tunnel　roof　collapse　mechanisms　are　also　presented.　Thereafter　a　series　of　stability　charts　of　the　required　supporting　pressure　and　the　factor　of　safety　(FoS)　FoS　)　is　proposed　for　design　purposes.　This　study　provides　a　theoretical　basis　for　design　and　engineering　of　tunnels　with　limited　buried　depth.