Detachable heightened steel buttress for portal frame and application method

The invention relates to a detachable heightening steel buttress for a portal frame and an application method, and belongs to the technical field of ship building. The detachable heightened steel buttress comprises a detachable connecting piece, a steel buttress used for supporting ship body sections and two connecting plates fixed to two sides of the portal frame, limiting holes are formed in two sides of the steel buttress, limiting grooves are formed in the two connecting plates, and the connecting piece sequentially penetrates through the limiting holes and the limiting grooves so that the steel buttress and the connecting plates can be detachably connected. The steel buttresses can be adjusted on the connecting plates in a sliding mode by loosening and tightening the connecting pieces so that the distance between the two steel buttresses on the portal frame is adjustable. The steel buttress can be quickly mounted and dismounted on the portal frame, and the fitting-out completeness of the segmentation sta