US 4,880,334 A · Tunnel construction apparatus and method

Abstract

According to the present invention, tunnels, particularly shallow tunnels, are constructed by excavating slurry filled cross-trenches in a direction transverse to the axis of the tunnel and at regular intervals along the line or axis of the tunnel. Prefabricated frame elements are inserted into the cross-trenches to, in essence, create the tunnel wall lateral support structure before the tunnel walls are installed. Then the tunnel sidewalls are excavated under bentonite clay or mud slurry to form cross-slots between the previously installed support frames. Precast concrete sidewalls or panels are inserted between the support frames. The frames and sidewalls have interlocking tongue and groove or keyway structures so as to interfit and lock same into position. When the sidewalls are in place, the roof of the tunnel may be either cast in place and then the soil excavated to form the actual tunnel and then the floor cast or the tunnel may be excavated down to the floor or invert level and then the floor or inverts cast and then the roof cast.

Claims6

Dependent claims

A method of constructing a underground tunnel along a given path, precasting in molds above ground at least a pair of frame elements, each frame element comprising a cross brace and a pair of vertical side column members, sidewall keyway means formed in said vertical side column members, precasting in molds above ground at least a pair of wall panel elements having lateral ends for adapted to enter said keyway means in respective ones of said vertical side column of said elements,

excavating, under the presence of a slurry, at least a pair of slots in the earth, said at least a pair of slots extending laterally transverse to the longitudinal direction of said tunnel along said given path,
inserting one each of said frame elements into each said rectangular slots in the earth,
excavating a pair of sidewall slots between the lateral ends of said pair of rectangular laterally extending slots,
inserting one each of said wall panels in said side slots and with the respective lateral ends in keyway engagement with said keyway means formed in said elements, and
forming a concrete floor and roof for said tunnel between said wall elements and said frame elements.

2 more elements

Dependencies are inferred from the claim text.

Tunnel construction apparatus and method

Life of this patent

Tunnel construction apparatus and method

Life of this patent

Abstract

Claims6