Abstract: The earth pressure shield for a tunnel and/or gallery excavator has a front working compartment formed by a separating wall having a digging tool and an annular reinforcing space substantially triangular in cross section positioned directly in front of the separating wall. So that an extensive restructuring of the machine is not necessary when moving from soft earth to hard ground, the annular reinforcing space is provided with a lower fluid feeder, a controlled upper pressurized air feeder, a plurality of fluid conductor pipes which are guided from below to an upper fluid outlet opening into the working compartment, and a fluid level controller. The invention is based on the consideration that a reliable and satisfactory support of the local front wall is only possible when the local front wall in the vicinity of the roof can be supplied with a fluid.

Abstract: The earth pressure shield contains a front working compartment having a digging tool and formed by a separating wall. An annular space is formed in the front working compartment with a top region connected with a regulated pressurized air feed and with a bottom region open to the digging tool so that dug or mined earth material is removable with the help of a conveyor unit. At least one fluid pipe is guided from a fluid chamber with a level controller and a fluid feeder to a fluid outlet open to the digging or mining tool in the working compartment. An especially reliable operation is attained when a bulkhead space is provided by partitioning behind the working compartment and/or the circular space formed with an immersed wall. This bulkhead space is connected in its upper region with the top region of the annular space by an opening in the separating wall and includes the fluid chamber in its lower region.

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: An apparatus for making a tunnel lining from concrete in a single operation with a tunnel excavator comprises a tunnel lining form consisting of a plurality of tunnel lining form segments and a form front adjacent the tunnel excavator and a tunnel lining circular space between the form and the ground. The concrete is selected so that it remains workable for more than two hours at a temperature of about 20.degree. C. but sets to a nonworkable state after 10 to 30 minutes upon heating to a temperature in the range of substantially 40.degree. C. to substantially 70.degree. C. The concrete is heated in a pipe section proximal to the compartment into which it is introduced by direct introduction of electrical energy into the pipe section.

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: An apparatus for making a tunnel lining from concrete in a single operation with a tunnel excavator comprises a tunnel lining form consisting of a plurality of tunnel lining form segments and a form front adjacent the tunnel excavator and a tunnel lining circular space between the form and the ground. In order to heat the concrete as it is pumped into the tunnel lining circular space to accelerate hardening, transmitting antennae for electromagnetic radiation are mounted in the tunnel lining form segments and/or the feed pipes for the concrete. Similarly a process for making a tunnel lining from concrete comprises pumping concrete into the tunnel lining circular space and accelerating the hardening of the concrete by heating it with electromagnetic radiation. The tunnel form is rapidly repositioned after the concrete being hardened reaches a sufficient strength.

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.