Patent Application
20110129300
The present invention is directed to steel liners for tunnels, and in particular to steel liners for tunnels where a tunneling machine may push off from the liners to dig the tunnel.
In a tunneling operation, a tunneling machine, either a tunnel digging machine or a tunnel boring machine, excavates material from the face of the tunnel as it moves forward and deposits the material behind the machine where it is removed from the tunnel. As a tunnel is dug, it is necessary to provide a liner for the tunnel behind the tunneling machine. Presently, liners are either wood beams supported by steel ribs, steel panels or concrete panels. Wood beams supported by steel ribs and steel panels are generally utilized where it is not necessary to provide for a watertight tunnel. If a watertight tunnel is required, concrete panels with a suitable sealing material between the panel sections are provided to result in a watertight tunnel liner.
Steel panels are easier to install than either of the wood beams or concrete panels. Presently available steel panels for lining a tunnel are generally formed from a steel sheet which is cut and stamped to provide for a surface which is a segment of a curve which lies against the surface of the tunnel. Upstanding flanges extend from the edges of the panel to provide a surface for joining one panel to another.
While such steel panels create an enclosure for the tunnel, there are certain disadvantages. In particular, the sealing and joining of the panels, especially at the corners, which due to the stamp forming operation, are generally not square, means that they may not be an optimal solution when a watertight tunnel is required.
The speed of a tunneling operation is directly related to the force which the tunneling machine can apply to the tunnel face to remove material. In some operations, it is desirable if the machine can push against a surface to increase the forward force at the tunnel face. With the construction of prior art steel liners, the steel panels generally do not provide a suitable surface for the machine to push against as they lack the structural integrity to support the pushing force.
There thus remains a need for a steel panel or segment for a tunnel liner which overcomes the disadvantages of the prior art.
The present invention is directed to a steel segment assembly for lining a tunnel. The steel segment assembly comprises a steel frame to which is attached a steel panel, the steel segment assembly being a segment of a cylinder dimensioned to the desired tunnel diameter. The frame is constructed of suitably dimensioned members having a rectangular cross section welded together with a curvature on one side of the frame to match the tunnel diameter. The frame comprises two curved spaced apart members to form the long sides of the frame, the curved spaced apart members being joined together at either end by end members to form the short sides of the frame. At least one intermediate member is provided between the two end members to bridge the curved spaced apart members to provide transverse structural support to the steel segment assembly.
In an aspect of the invention, the segment assembly has a square, rectangular or trapezoidal shape.
In another aspect of the invention, a plurality of intermediate members are provided between the two end members.
In another aspect of the invention, four intermediate members are provided per segment assembly
The present invention also provides for a tunnel lining comprising a plurality of steel segment assemblies arranged in rows of end to end joined individual steel segment assemblies. Each of the steel segment assemblies comprises a frame to which is attached a steel panel, the segment assembly being a segment of a cylinder dimensioned to the desired tunnel diameter. The frame is constructed of suitably dimensioned members having a rectangular cross section welded together. The frame comprises two curved spaced apart members to form the long sides of the frame, the curved spaced apart members being joined together at either end by end members to form the short sides of the frame. At least one intermediate member is provided between the two end members to bridge the two curved spaced apart members to provide transverse structural support to the steel segment assembly. A first plurality of steel segment assemblies are joined end to end to complete a cylinder comprising a row of the tunnel diameter. The individual rows are connected to one another to form the tunnel lining.
In an aspect of the invention, each of the steel segment assemblies are provided with a plurality of intermediate members between the two end members, the intermediate members of each row being aligned to provide a continuous support so that the load of a tunnel digging machine pushing back against the tunnel lining is transferred along the length of the lining.
Preferred embodiments of the present invention are illustrated in the attached drawings, in which:
The present invention is directed to a steel segment assembly 20 for lining tunnels. As illustrated in
The segment assemblies 20 have a square, rectangular or trapezoidal shape, depending upon the configuration of the tunnel. For straight tunnel runs, the segment assemblies 20 will be generally square or rectangular. Where it is desired to change the direction of the tunnel, the segment assemblies 20 will be trapezoidal in shape as described further below.
Each of the steel segment assemblies 20 has a frame 22 to which is attached a steel panel skin 24. The frame 22 has parallel, curved spaced apart members 26 along the long side of the frame 22, the curved spaced apart members 26 being joined at their ends by end members 28 to form the short sides of the frame 22. The curved spaced apart members 26 and end members 28 are formed from a suitably dimensioned material to provide structural support for the segment assembly 20. Preferably, the spaced apart members 26 and end members 28 are formed of ¼ to ½ inch bar or plate stock cut and formed to the proper configuration for the final shape of the segment assembly 20.
The spaced apart members 26 and end members 28 are connected to one another by welds 30 which extend along the full joint between the members. These full length welds 30 leave no openings or voids and aid in making the steel segment assembly 20 useful for watertight tunneling applications as will be described below.
The frame 22 is also provided with at least one intermediate member 32 which connects the spaced apart members between the ends to provide transverse structural support to the segment assembly 20. The number and location of the intermediate members 32 are provided depending upon the structural design criteria of the overall tunnel liner. Preferably, a plurality of such intermediate members 32, more preferably four such intermediate members 32 are provided for each segment assembly 20. As illustrated in the figures, the intermediate members 32 are located in the interior of the frame 22 such that when the plurality of segment assemblies 20 are joined to form the complete circle, the spacing between the intermediate members 32 around the complete circle is on the order of 15°.
In order to provide for a suitable surface against which a tunneling machine can push, it is preferred if the intermediate members 32 are formed of a structural component such as structural metal tubing dimensioned to withstand the forces exerted by the tunneling machine. As illustrated in the figures, more preferably, intermediate members 32 are of a structural metal tube and the intermediate members 32 are connected to the spaced apart frame members 26 by a continuous weld 34 around the full circumference of the ends of the intermediate members 32.
The steel panel skin 24 is attached to the curved surface of the frame 22 by continuous welds 36 at the junction between the interior of the frame 22 and the steel panel skin 24. These continuous welds 36 leave no openings or voids between the steel panel skin 24 and frame 22 and aid in making the steel segment assembly 20 useful for watertight tunneling applications as will be described below.
As the frame 22 provides the structural support for the steel segment assembly 20 of the present invention, the gauge of the steel panel skin 24 may be significantly less than prior art panels. Preferably, the steel panel skin is formed from an 18 gauge steel. This makes for easier bending of the steel panel skin 24 to conform to the desired diameter of the tunnel as compared to prior art panels.
The steel segment assemblies 20 of the present invention are particularly useful for tunnels requiring a lining resistant to the ingress of fluid into the tunnel. The joints between the individual segments 20 are provided with sealing strips 40 which provide for a seal between the segments 20. Preferably, the sealing strips 40 are of a suitable compressible elastomeric material such as a suitable durometer rubber which is compressible between the edges of the panels 24 to seal against the ingress of fluid into the tunnel, as will be described further below.
There are circumstances when digging a tunnel where the direction of the tunnel may be required to be varied. For example, the depth of the tunnel may change depending upon the design of the tunnel. In other situations it may be necessary to vary the lateral direction of the tunnel. In these situations, the direction of the tunnel liner must also be varied. This may be accomplished by using steel segment assemblies 20A having a trapezoidal shape with varying depths as shown in
The steel tunnel section 10A will having a tapered depth from one side to another. In the embodiment illustrated in the figures, one side of the tunnel section 10A has a depth of about 6 inches tapering to a depth of 12 inches at the other side. Other dimensions for the segment assemblies will be apparent to those of skill in the art. Through the use of a plurality of such tunnel sections 10A, the direction of the tunnel may be varied.
As illustrated in
The installation of the steel segment assemblies to provide a tunnel lining is illustrated in
As the tunnel digging machine 50 moves forward, the steel segment assemblies 20 are installed to provide the tunnel lining. A hydraulically operated lifting apparatus 60 is provided to lift and place the steel segment assembly 20 in the proper location. The sealing strips 40 are placed in the proper position and the steel segment assembly is attached to the existing tunnel lining using suitable bolts 62 placed in the aligned openings 38 of the steel segment frame 22. Nuts 64 are placed on the bolts 62 and tightened down to sealingly connect the steel segment assembly to the tunnel lining.
As illustrated in
As illustrated in the figures, each row of the steel segment assemblies is offset so that the end joints between adjacent rows do not line up with each other. The rows of steel segment assemblies are aligned so that the transverse intermediate members 32 align to provide a continuous support so that the load of the tunnel digging machine pushing back against the tunnel lining is transferred along the length of the lining.
While the embodiments described above utilizes half segments 20-1 and 20-2 to fill in the last part of the tunnel liner section, an alternative arrangement could utilize full segments. As illustrated in
The steel segment assemblies of the present invention provide for an easy to install steel tunnel lining which resists the ingress of fluid and other materials into the tunnel and allows the tunnel digging or boring machine to push against the tunnel lining to increase the digging or boring force to thereby increase the speed of the tunneling operation.
While various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those of skill in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
