504 EM 385-1-1 Sections 27-34

28.B.23 Open web steel joists.

2. Where constructability does not allow a steel joist to be installed at the column:
• (1) An alternate means of stabilizing joists must be installed on both sides near the column and must:
• (a) Provide stability equivalent to Section 28.B.23.a (1) above,
• (b) Be designed by a QP,
• (c) Be shop installed, and
• (d) Be included in the erection drawings.
• (2) Hoisting cables must not be released until the seat at each end of the steel joist is field-bolted and the joist is stabilized.
3. Where steel joists at or near columns that span 60 ft (18.3 m) or less, the joist must be designed and erected by either:
• (1) Installing bridging or otherwise stabilizing the joist prior to releasing the hoisting cable or,
• (2) Releasing the cable without having a worker on the joist.
4. Where steel joists at or near columns span more than 60 ft (18.3 m), the joists must be set in tandem with all bridging installed unless an alternative method of erection, which provides equivalent stability to the steel joist, is designed by a QP and is included in the site-specific Steel Erection Plan.
5. A steel joist or steel joist girder must not be placed on any support structure unless such structure is stabilized.
6. When steel joist(s) are landed on a structure, they must be secured to prevent unintentional displacement prior to installation.
7. No modification that affects the strength of a steel joist or steel joist girder must be made without the approval of the project structural engineer of record.
8. Field-bolted joists.
• (1) Except for steel joists that have been pre-assembled into panels, connections of individual steel joists to steel structures in bays of 40 ft (12.1 m) or more must be fabricated to allow for field bolting during erection.
• (2)These connections must be field-bolted unless constructability does not allow.
9. Steel joists and steel joist girders must not be used as anchorage points for a fall arrest system unless written approval to do so is obtained from a QP.
10. A bridging terminus point must be established before bridging is installed

28.B.24 Attachment of steel joists and steel joist girders.

1. Each end of "K" series steel joists must be attached to the support structure with a minimum of two 1/8-in (0.3-cm) fillet welds that are 2 in (5 cm) long, or with two 1/2-in (1.2- cm) bolts, or the equivalent.
2. Each end of "LH" and "DLH" series steel joists and steel joist girders must be attached to the support structure with a minimum of two1/4-inch (0.6-cm) fillet welds 2 in (5 cm) long, or with two 3/4-in (1.9-cm) bolts, or the equivalent.
3. Except as provided in paragraph d below, each steel joist must be attached to the support structure, at least at one end on both sides of the seat, immediately upon placement in the final erection position and before additional joists are placed.
4. Panels that have been pre-assembled from steel joists with bridging must be attached to the structure at each corner before the hoisting cables are released.

28.B.25 Erection of steel joists.

1. Both sides of the seat of one end of each steel joist that requires bridging under Tables 28-1 and 28-2 must be attached to the support structure before hoisting cables are released.

2. For joists over 60 ft (18.2 m), both ends of the joist must be attached as specified in Section 28.B.24 and the provisions of Section 28.B.26 are met before the hoisting cables are released.
3. On steel joists that do not require erection bridging under Tables 28-1 and 28-2, only one employee must be allowed on the joist until all bridging is installed and anchored.
4. Employees must not be allowed on steel joists where the span of the steel joist is equal to or greater than the span shown in Tables 28-1 and 28-2 in accordance with Section 28.B.26.
5. When permanent bridging terminus points cannot be used during erection, additional temporary bridging terminus points are required to provide stability.

Knowledge Check Choose the best answer for the question.