Tunnel liners and methods of making the same

A tunnel liner annulus for changing direction of the liner comprising a plurality of end to end liner segments bolted together at the ends, sealing means between adjoining ends, said liner segments each comprising a pair of liner plates each having a curved elongated skin forming an arc of said annulus, each skin having spaced dependent sidewalls bent at an angle thereto, each successive pair of liner plates in the annulus being in spaced apart side-by-side relationship, spaced apart a greater distance at one end than at the other end, a pair of wedge shaped gusset plates in spaced parallel planes fixed to the sidewalls betwen said liner plates adjacent the top and bottom respectively of the adjacent sidewalls and an end plate at each end of said pairs of liner plates extending the remote sidewalls of each segment and connected to the sidewalls, gusset plates and skins to form a unitary whole, and said segments being arranged so that the wedge shaped gusset plates are in ascending order to a selected maximum and then in descending order to a minimum.