Abstract: A tunnel lining comprises a plurality of arcuate concrete tunnel lining segments. Each segment has at each circumferential end thereof two semi-cylindrical grooves spaced apart along the end and extending partway across the end. One of the grooves has two semi-circular hoops projecting from the end of the segment across the groove at spaced postions along the groove and the other groove has a single semi-circular hoop projecting from the end of the segment across the groove. Two segment ends are located together with respective hoops in alignment and tapered pins or other fastening devices are driven into the aligned hoops to draw and hold the segment ends together in compression.