Custom Engineered Solutions

VIERENDEEL OPENINGS

Vulcraft’s joists can be custom designed with rectangular Vierendeel openings to allow large heating, ventilation, and air conditioning (HVAC) ducts to pass through the open web system. Doing so reduces the required floor-to-floor height, as the MEP can run through the Vierendeel opening rather than beneath the joist bottom chord.

The Vierendeel opening should be located near the minimum vertical shear across the steel joist (typically near the joist mid-span for a uniformly loaded joist). Doing so reduces the combined vertical shear forces required to be carried by the joist top and bottom chords, resulting in the greatest joist weight savings. Vierendeel openings provide maximum flexibility with MEP layout – making them ideal for multi-story buildings.

DESIGN SPECIFICATIONS

Vierendeel openings should be located within the center third of the joist span

Multiple openings should be spaced a minimum of two times the joist depth apart

Partial span live loading will be checked by Vulcraft

The maximum width of the Vierendeel opening should be no greater than two times the depth of the steel joist

Locations can be indicated on plans or joist elevations

Clear opening dimensions should be given

Any special loading conditions should be provided

JOIST FLUSH FRAME CONNECTIONS

Vulcraft’s Flush Frame Connections are modernizing steel joist floor systems. Recent research shows that our Flush Frame Connections significantly mitigate floor vibration* making your building safer and more comfortable. Designed to reduce floor-to-floor heights, simplify MEP installation, and accelerate deck installation, Flush Frame Connections also combine the strength of a wide flange beam connection with the lightweight advantages of an open web joist.

As the name implies, Vulcraft’s Flush Frame Connection places the joist’s top chord flush with the girder’s top flange, bolting the joist plate to a shear tab on the girder. These connections are another example of how Vulcraft’s steel joist floor systems provide more options and less vibration.

* As measured by finite element analysis and manual calculation methods.