The supporting arch is for use in mine galleries. It consists of a number of trough sections forming segments fitting together and secured by clamping collards where they overlap. Where this overlapping of the segments takes place (3, 4) their faces opposite each other are held apart by intermediate pieces (8), which are relatively short compared to the amount of overlap. The pieces can be detachably mounted on the support segments, and they can be shaped to fit the outlines of the segment faces. They can be in the form of short channel sections similar to the straight portions of the segments.