METHOD OF ASSEMBLING AND PLACING OVERLAPPED CHANNEL GIRDER SECTIONS TO FORM ROOF SUPPORTING ARCHES IN AN UNDERGROUND ROADWAY AND APPARATUS FOR PERFORMING THIS METHOD

摘要

1534142 Method of assembling roof arches BOCHUMER EISENHUTTE HEINTZMANN & CO 20 Nov 1975 [15 Jan 1975] 47874/75 Heading E1E A method of assembling roof arches comprises placing channel sections 3, 4 so that the end portions overlap and diverge at an angle α which opens in the directions of the floor and/or side of the roadway (when the arch is in situ) so that the cross-section of the preassembled arch is less than that of the roadway, connecting the end portions by clamps 12, 20, and erecting the preassembled arch by expanding and tightening it against the side wall by reducng the angle α and (optionally) reducing the length of overlap. The angle α is maintained by fixed or releasable spacers 26 which are interposed between the edge flanges 19 of the channel sections 3, 6. The spacers may comprise plates 26 or wedges, Fig. 5 and 6 (not shown), welded to the clamp from which they are removed before final erection. Alternatively the wedges are pivoted in the clamp bolts to be rotated out of the way. In a further alternative, Fig. 11, two clamps, are in each section, are connected by a length adjustable tension member 50, 51 and a clasp 45 attached to the channel section 3 provides a hinge. In a modification a length of chain is used as the tension member.