Abstract: A tunnel excavating machine for generating tunnels and galleries in subterranean structures, comprises in addition to the excavating head, a shield which travels with the head and advances along the excavation and lines the tunnels wall at least temporarily. According to the invention, the shield is formed by at least two shield sections which are preferably cylindrical and can be axially spaced apart while being bridged by a seal for the gap between them. The two shield sections are connected by a plurality of angularly equispaced piston-and-cylinder arrangements preferably of the double-acting type to allow angular offsetting of the axes of the two shield sections.

Abstract: A method of lining a tunnel wall comprises the pumping of concrete between a support and the tunnel wall, the concrete being selected from the concretes of concrete group BII of German Industrial Standard (DIN) 1045 and containing as an additive, steel pins, rods or wires having a length of 35 to 50 mm and a diameter of 0.8 to 1.2 mm. Approximately 100 kg/m.sup.3 of concrete is constituted by the steel pins or wires.

Abstract: A tunnel lining is formed by pumping concrete between a support and a tunnel wall, the concrete being selected from the concretes of concrete group BII of German Industrial Standard (DIN) 1045 and containing as an additive, steel pins, rods or wires having a length of 35 to 50 mm and a diameter of 0.8 to 1.2 mm. Approximately 100 kg/m.sup.3 of concrete is constituted by the steel pins or wires.