Lattice Girders / 3 Bars

With spaced diagonals, 3 bars are assembled to form a girder. The single bar can be located against the ground or towards the inside of the tunnel, fitting a specified design geometry. The spaced stiffening elements reduce the local buckling length of the bars, assure a high normal and bending moment resistance, and secure a transfer of lateral forces in the lining before the shotcrete has reached its design strength.

Lattice Girders / 4 Bars

With spaced diagonals, 4 bars are assembled to form a girder. Fabrication of the girder to the design geometry is possible. The spaced stiffening elements reduce the local buckling length of the bars and assure a high normal and bending moment resistance as well as a secure transfer of lateral forces in the lining before the shotcrete has reached its design strength.