Ktrusses

Ktrusses, or K-trusses, are a class of truss used in bridges and building frames characterized by a web configuration that forms a K-shaped pattern within each panel. The defining feature is a vertical web member combined with a diagonal that connects to that vertical, creating a K-shaped arrangement when viewed in the plane of the truss. This web geometry provides an additional load path for shear forces and can allow a shallower, stiffer panel for a given span compared with plain Pratt or Howe configurations.

In a typical K-truss, diagonals and verticals are arranged so that the diagonal intersects or terminates at a point on a vertical member, producing the recognizable K shape at each panel. Variants exist with different placements of diagonals and verticals, but the essential concept remains the same: the K-shaped web enhances stiffness and distributes loads more efficiently than simpler truss forms.

Advantages of K-trusses include increased lateral stiffness and a more favorable distribution of forces, which can reduce bending moments in the chords and enable longer spans without increasing overall depth. Disadvantages include greater complexity of fabrication and assembly, more members to connections to maintain, and potentially higher fabrication costs compared with simpler trusses.

K-trusses were widely used in early-to-mid 20th-century steel bridge design and in some large roof and industrial framing. Today they are often found in historic structures and in specialized applications where their geometry remains advantageous.