Lattice beam with bars and bracing, especially for tunnelling

摘要

The beam is constructed from three parallel bars, which are arranged as the vertices of a triangle. The bars are fastened to one another by welded bracing, which also fulfils a separating function. The bracing is paired into V-shaped arrangements which are linked into a crib. Both limbs of an arrangement are bent with a curve (T2), and the ends of the limbs are connected to one another with a curve (T1). One curve (T2) of the bracing is bent over a bar (1), and the other curve (T1) lies alongside the outside of a bar (2). The latter is also bent out of the plane connecting the two bars, at least as far as a vertical construction plane, in order to increase the area of the joint.