Abstract: A lattice girder for support of a tunnel structure includes coupling elements arranged on ends of the lattice girder. Each coupling element has two sheet-metal strips having each an end formed with a loop. Extending between the coupling elements in a longitudinal direction of the lattice girder are two lower bars and an upper bar arranged to define corners of a triangle in cross section. A framework made of single braces connects the lower bars with the upper bar. Connectors are received in the loops of the sheet-metal strips.

Abstract: A tubbing lining for a tunnel or shaft is formed from tubbing rings having annular end surfaces, with successively tubbing rings are aligned with each other at annular end surfaces forming an annular joint. Each tubbing ring is composed of successive circumferentially arranged tubbing segments which are butt-joined. A deformable flexible element having an outer cross-sectional contour is arranged in at least one butt joint, with the cross-sectional contour parallel to the butt joint matching outer contours of the end faces such that the flexible element completely covers at least one abutting end face. The tubbing segments in conjunction with the flexible element form a prefabricated element formed of a steel reinforcing framework encased in concrete to which the flexible element is connected in a force-locked manner.

Abstract: A lattice girder for support of a tunnel structure includes coupling elements arranged on ends of the lattice girder. Each coupling element has two sheet-metal strips having each an end formed with a loop. Extending between the coupling elements in a longitudinal direction of the lattice girder are two lower bars and an upper bar arranged to define corners of a triangle in cross section. A framework made of single braces connects the lower bars with the upper bar. Connectors are received in the loops of the sheet-metal strips.

Abstract: A tubbing lining for a tunnel or shaft is formed from tubbing rings having annular end surfaces, with successively tubbing rings are aligned with each other at annular end surfaces forming an annular joint. Each tubbing ring is composed of successive circumferentially arranged tubbing segments which are butt-joined. A deformable flexible element having an outer cross-sectional contour is arranged in at least one butt joint, with the cross-sectional contour parallel to the butt joint matching outer contours of the end faces such that the flexible element completely covers at least one abutting end face. The tubbing segments in conjunction with the flexible element form a prefabricated element formed of a steel reinforcing framework encased in concrete to which the flexible element is connected in a force-locked manner.

Abstract: A peripherally flexible arch for propping rock structure for mining tracks, tunnels or the like is comprised of a plurality of partially overlapped elongated segments, each of which has an end portion extended toward the rock structure, a bottom portion opposite to the end portion, and a lateral flange offset from the end portion laterally and in the direction toward the bottom portion. Clamping devices are arranged at the ends of the overlapping regions of the segments to clamp the segments to each other. The end portion of each lower segment is inserted into a groove formed between the end portion and the flange portion of each upper segment at the side of this segment facing away from the rock structure. Each clamping device has a hook engaged in a groove formed between the end portion and the flange of the upper segment at the side of this segment facing toward the rock structure.

Abstract: A shut-off valve has a sealing cone which in a closed position of the valve abuts against a conical sealing seat and is formed as a part of a cylindrical throttling piston, a sealing surface of the sealing seat cooperates at its one end with a cylindrical receiving opening for the throttling piston, and the outer diameter of the throttling piston is selected with respect to the inner diameter of the receiving opening so that a throttling gap is formed between the receiving opening and the the throttling piston.

Abstract: A clamping device for connecting a number of shaped, elongated, flanged through sections of a support structure to each other includes an upper stirrup, the flanges of which are supported on the flanges of the upper through section, a lower stirrup positioned to support the flanges of the lower through section, and clamping bolts extended through the openings in the flanges of the stirrups and the through sections and tightened with nuts. The head of each bolt has supporting projections provided with convexly curved portions which are engaged in the flanges of the upper stirrup in a form-locking fashion.

Abstract: A rock anchoring arrangement for use in tunnel and mine constructions comprises an elongated anchoring rod insertable in a bore formed in a rock formation, and a supporting plate arranged in contact with the rock formation at the open end of the bore. The anchoring rod includes a leading end portion fixable at the bottom of the bore, a trailing end portion fixable at the open end of the bore, and a smooth intermediate portion of a cross-sectional area smaller than those of the trailing end portion and the leading end portion. The anchoring rod is fixable by an adhesive within the bore at the leading end portion and at the trailing end portion whereas the intermediate portion is surrounded by an adhesive-repellent material to prevent the sticking thereof to the adhesive.

Abstract: A wall element for an underground gallery has a W-shaped member which is symmetrical relative to its y-axis and has an axis of gravity coinciding with its x-axis and lying at approximately the center of its side, wherein the thickness of its lateral flange portions, base portions and connecting web portions are selected so that, in relation to used weight per meter, the W-shaped member has a maximum possible moment of resistance relative to the x-axis and a maximum possible bending load capacity in the plastic deformation range, and the W-shaped member has such a profile and such thicknesses of these portions that it has at least approximately equal bending load capacities in the plastic deformation region in two opposite directions along the y-axis.