Vertical bracings are applied both to columns (flange and web) and to beams (to flange). Usually when the bracing is attached to a column, the bracing is supplemented by a hinged secondary beam. The connection of this secondary beam is an “extended” connection to allow the welding of the horizontal side of the gusset plate.
If two bracings are connected to the same beam, the gusset plates of the two diagonal elements are automatically merged.
If the two bracings have the same cross-section, also the connection will be the same.
The cross-section of the diagonals can be:
- I or H rolled sections (Hsm)
- Angles (Lsm)
- UPN (UPN)
- Double UPN (cross-section coding)
- Double angles (cross-section coding)
- PFC (parallel flange channels) (cross-section coding)
There is also a welded joint type.
The type using a bolted splice on the diagonal is available both for bracings connected to a beam and for bracings connected to a column, flange and web. Here below an example of double bracing with two bolted splice joints, to column flange. It must be noted the the beam connection is of the type “extended hinge” as it must receive the diagonal, also.
The previous type is applicable only to diagonals having a cross-section of type I or H rolled, and only if the diagonal is at least partially in contact with the master element. Connections where the welded trunk is only connected to the beam, are excluded.
Gusset plate types
The gusset plate types, welded or bolted, to web or flange, can be of three different types:
- Extended gusset. In this case two 30° straight diffusion lines are drawn from the extremities of the gusset plate. The gusset plate results then larger (“extended”).
- Reduced gusset. In this case the two 30° straight diffusion lines are drawn from the last bolt. The gusset plate results then of a smaller size (“reduced”).
- UFM (Uniform Force Method) gusset plate. In this case, the ratio between the contact-side lenghts, respectively to the master member and to the secondary beam, is given. The plate results havng optimal size to be checked using the Uniform Force Method.
It is up to the user to choose, before sending a request to the Service, which typology og gusset plate will be used. The choice is comprised among the design criteria.
In the following pictures, using the same identical members, the three types can be seen both in the case of flange-connection and in the case of web-connection (in the pictures the master is a column).
