Existing　research　studies　have　primarily　examined　the　progressive　collapse　of　frame　structures　under　an　inner　column　removal　scenario.　However,　progressive　collapse　risk　is　much　higher　when　penultimate　columns　close　to　the　structural　periphery　are　damaged　due　to　weaker　horizontal　constraints.　A　static　progressive　collapse　test　was　thus　conducted　in　this　study　on　two　single-story　beam-column　planar　substructures　with　flange　slabs,　in　which　a　penultimate　and　an　inner　column　were　removed　respectively.　Compared　to　the　specimen　with　an　inner　column　removal,　the　specimen　with　a　penultimate　column　removal　exhibited　a　larger　vertical　displacement　under　the　small　deformation　stage,　which　further　reduced　the　contribution　of　the　compressive　arch　action　to　the　collapse　resistance.　Under　the　large　deformation　stage,　the　resistance　of　the　specimen　with　an　inner　column　removal　increased　significantly,　while　that　with　a　penultimate　column　removal　was　not　enhanced　notably　because　the　horizontal　movement　of　its　edge　column　resulted　in　a　smaller　rise　of　steel　strains　under　the　catenary　action.　The　internal　forces　were　calculated　using　the　measured　strain　data　at　the　key　sections　of　the　slab-flange　beams.　The　calculated　results　also　confirm　that　the　compressive　arch　action　and　catenary　action　were　unable　to　be　fully　developed　in　the　specimen　with　a　missing　penultimate　column.　Finally,　the　outcome　of　the　vulnerability　assessment　of　the　prototype　reinforced　concrete　frame　reveals　that　there　might　be　a　potential　risk　of　progressive　collapse　to　the　structure　under　large　deformations　when　a　penultimate　column　on　the　ground　floor　is　damaged　and　the　risk　is　higher　when　a　penultimate　column　on　the　top　floor　is　damaged.