Structural plates and methods of constructing arch-shaped structures using structural plates. Structural plates may include a combination of features including: an outer structural plate having adjacent circumferential apertures respectively spaced nominally greater than adjacent circumferential apertures of an inner structural plate; and the outer structural plate having nominally 5 enlarged or differently shaped circumferential apertures (as compared to circumferential apertures of the inner structural plate) such that the embodiment structural plates may be radiused to a variety of different radii while achieving desirable overlapping alignment of apertures along overlapping circumferential edges for receiving fasteners therein. Joiner plates may be provided for interconnecting structural plates along transverse edges in a non-overlapping arrangement, 10 thereby reducing the quantity of structural plate material that otherwise would be needed for a given circumferential length of the arch-shaped structure.

An adjustable lattice girder includes a first lattice girder portion having a first end and a second end positioned opposite the first end, with the first lattice girder portion having a first connection member, and a second lattice girder portion having a first end and a second end positioned opposite the first end, with the second lattice girder portion having a second connection member configured to engage the first connection member. The first connection member is slidable relative to the second connection member between a first position corresponding to a first distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion, and a second position corresponding to a second distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion. The first distance different than the second distance.

An adjustable lattice girder includes a first lattice girder portion having a first end and a second end positioned opposite the first end, with the first lattice girder portion having a first connection member, and a second lattice girder portion having a first end and a second end positioned opposite the first end, with the second lattice girder portion having a second connection member configured to engage the first connection member. The first connection member is slidable relative to the second connection member between a first position corresponding to a first distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion, and a second position corresponding to a second distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion. The first distance different than the second distance.

A double-walled tube section for constructing a double-walled tube segment suitable for underpressure applications such as an evacuated tube transport system.

An adjustable lattice girder includes a first lattice girder portion having a first end and a second end positioned opposite the first end, with the first lattice girder portion having a first connection member, and a second lattice girder portion having a first end and a second end positioned opposite the first end, with the second lattice girder portion having a second connection member configured to engage the first connection member. The first connection member is slidable relative to the second connection member between a first position corresponding to a first distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion, and a second position corresponding to a second distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion. The first distance different than the second distance.

An adjustable lattice girder includes a first lattice girder portion having a first end and a second end positioned opposite the first end, with the first lattice girder portion having a first connection member, and a second lattice girder portion having a first end and a second end positioned opposite the first end, with the second lattice girder portion having a second connection member configured to engage the first connection member. The first connection member is slidable relative to the second connection member between a first position corresponding to a first distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion, and a second position corresponding to a second distance between the second end of the first lattice girder portion and the first end of the second lattice girder portion. The first distance different than the second distance.

Segments each having side plates 102 and 103 and a plurality of inner plates 106 and 107 inside the side plates are coupled in the circumferential direction and in the longitudinal direction to construct a rehabilitation pipe inside an existing pipe. A plastic nut retainer 50 for retaining therein a nut 60 engaged with a coupling bolt 11 is attached between the side plate 102 on one side of the segment 1b and the inner plate 106 adjacent thereto. The coupling bolt is screwed into the nut co couple the segments 1a and 1b in the longitudinal direction due to clamping by screwing. A groove is formed in the nut retainer, and the nut is press-fitted into the groove and retained in the nut retainer.

A rib for supporting and consolidating an excavation comprises at least a first structural element (5A) and at least one connection element (10) for connecting the said structural element (5A) of the said rib to a corresponding connection element (10) of an adjacent rib (1), the said connection element (10) being capable of engaging through translatory motion with the said corresponding connection element (10) of the adjacent rib.

A rib for supporting and consolidating an excavation comprises at least a first structural element (5A) and at least one connection element (10) for connecting the said structural element (5A) of the said rib to a corresponding connection element (10) of an adjacent rib (1), the said connection element (10) being capable of engaging through translatory motion with the said corresponding connection element (10) of the adjacent rib.

Structural plates and methods of constructing arch-shaped structures using structural plates. Structural plates may include a combination of features including: an outer structural plate having adjacent circumferential apertures respectively spaced nominally greater than adjacent circumferential apertures of an inner structural plate; and the outer structural plate having nominally 5 enlarged or differently shaped circumferential apertures (as compared to circumferential apertures of the inner structural plate) such that the embodiment structural plates may be radiused to a variety of different radii while achieving desirable overlapping alignment of apertures along overlapping circumferential edges for receiving fasteners therein. Joiner plates may be provided for interconnecting structural plates along transverse edges in a non-overlapping arrangement, 10 thereby reducing the quantity of structural plate material that otherwise would be needed for a given circumferential length of the arch-shaped structure.