Abstract: A tunnel having an inner surface and extending along an axis is lined with pumpable concrete having a predetermined hardening time and by a form having an annular inner wall and an axially movable front wall. Substantially equal sized batches of pumpable concrete are successively injected into the space through the movable front wall through a plurality of angularly equispaced ports therein. The batches are injected axially backwardly through the ports at such a rate that succeeding batches are injected through each port at a time interval that is substantially smaller than the concrete hardening time. The front wall is displaced forward at such a rate and the batches are sized such that each batch spreads over a predetermined axial and a predetermined angular distance, such that the latter is greater than the former.

Abstract: For continuously lining a tunnel with extruded concrete a pumping device for feeding the concrete and a form having an interior form member and a forwardly movable form front are employed. The extruded concrete is put into place without clump formation, when it is provided in equal-sized segments in a plurality of equal constant amounts which are fed in succession one after the other circumferentially in a time interval which is small compared to the hardening time of the concrete. For this purpose the form front is provided with a plurality of concrete input ports uniformly distributed circumferentially and connected with the pumping device, while the pumping device is designed to service the concrete input ports in succession one after the other circumferentially.

Abstract: A bearing assembly for the shaft of a boring head for an excavating machine comprises four piston-and-cylinder units bridged between the bearing and a support ring and pivotally connected thereto, the units lying along sides of an imaginary parallelogram of adjustable and inclined angle and side length.

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.