Patent GB-357196-A (GB)
Title: Method and apparatus for driving tunnels and headings
IPC: E21D9/06
Filed: 1930-05-09
Abstract: 357,196. Tunnelling &c. SCHAEFER, H., 2, Friedrichstrasse, Essen, Germany. May 9, 1930, No. 14385. [Classes 68 (i) and 85.] In driving tunnels or headings by means of driving cutters mounted on centerings and breast shields which protect the working face, cutters which deviate from the desired direction are deflected back into said direction by means of wedge members detachably secured to the cutters. At the beginning of the funnel, spaced centerings 1 are set up to support driving cutters 2 which may be circularly arched or channelled, the cutters forming a continuous shell or one open below. The cutters have engaging parts 2x, 2y, Figs. 7, 9 and 10, for self-guiding and rubber &c. facings 21, Fig. 9, may be provided. The lining 3, Fig. 1, is then commenced and filling 5 of concrete or clippings inserted ; the rear ends 2o of the cutters may be box-shaped to receive filling material which is ejected by the jacks 9 which advance the cutters. The front ends of the cutters may also be box-shaped to receive, after removal of soil therefrom, means for noting the position of the cutters. If deviation has occurred, an inwardly or outwardly directed head 10<1>, Fig. 14, or a head with an oblique rib 10<11>, Fig. 17, is detachably fixed to the cutter before the next advance. In soft ground; auxiliary cutters 10 are provided within the cutters 2 and are advanced first, the earth below them being then removed and the auxiliary cutters supported by props 11 during advance of the man cutters. Similar auxiliary cutters with integral deflecting points may be used to correct deviation of the main cutters, being driven slightly in advance of the main cutters and then connected thereto for further advance ; wedge heads 12,.Fig. 13, may be loosely secured to the auxiliary cutters, such heads becoming automatically detached when the front ends of the auxiliary cutters reach the front ends of the main cutters. When the tunnel is to be driven round a curve, the normal circular centerings 1 are replaced by polygonal centerings, the original cutters 2 being deflected out into the soil, and cutters curved to suit the curve of the tunnel substituted therefor. The working face is supported by breast shields 13, Figs. 1 and 4, advanced successively from above downwards and held by jacks 14 bearing against the centering 1 or against clamps 17, Fig. 4, secured to the driving cutters 2, or by diagonallyarranged jacks 141, Fig. 1, bearing against a cross stay 15 ; the breast shields overlap and means may be provided to connect adjacent shields. In soft or wet ground, pipes 18, 18<1>, Fig. 1, may be inserted through the breast shields and quick-setting binding material injected to form a hollow wall 19<11>; the ground within this wall may then be consolidated by slow setting cement supplied through upper pipes 18a, water being run off through lower pipes 18b. In other cases, binding material may be injected to consolidate upper sections 19x, Fig. 4, of the ground which afterwards form supports for the driving cutters. To drain water from the soil, a pipe r, Fig. 4, or advance heading may be driven, and drainage pits g sunk ; the pits may be lined with perforated pipe.