513 EM 385-1-1 Chapters 23-29

Sections

28-8. General Requirements.

Open Web Steel Joists

Lateral stability must be ensured during erection by field bolting a steel joist at the column, using a vertical stabilizer plate, and stabilizing the bottom chords. Hoisting cables are not to be released until proper bolting and restraint are confirmed.
If constructability restricts joist installation at the column, an alternate stabilization method designed by a Qualified Person (QP) must be implemented, and hoisting cables must remain intact until stabilization is achieved.
For joists near columns spanning 60 feet or less, ensure stabilization before releasing hoisting cables or ensure no workers are on the joist when cables are released. For spans exceeding 60 feet, set joists in tandem with all bridging installed, unless an alternative QP-designed method is included in the site-specific Steel Erection Plan.

Attachment of Steel Joists and Steel Joist Girders

"K" series steel joists must be attached to the support structure with specified welds or bolts. "LH" and "DLH" series require specific attachment methods as well.
Steel joists must be attached to the support structure immediately upon placement, except for pre-assembled panels which must be attached at each corner before releasing hoisting cables.

Erection of Steel Joists

Attach joists requiring bridging to the support structure as specified, and adhere to bridging requirements from tables 28-1 and 28-2 before releasing hoisting cables.
Limit personnel on joists not requiring erection bridging until all bridging is installed and anchored, and prohibit personnel on joists with spans equal to or greater than specified in tables 28-1 and 28-2.
Install temporary bridging terminus points when permanent ones can't be used during erection to ensure stability.

Knowledge Check Choose the best answer for the question.

28-8. Lateral stability must be ensured during erection by _____.

releasing hoist cables

stabilizing the bottom cords

release hoisting cables at each end of the joist

field bolting a steel joist at the column

You forgot to answer the question!

EM 385-1-1 Paragraph 28-8 (s.–u.).

28-8. General Requirements.(s.–u.).

s.  Open web steel joists.  (28-8.s)

(1)  Except as provided in paragraph 28-8.s(2) below, where steel joists are used and columns are not framed in at least two directions with solid web structural steel members, field bolt a steel joist at the column to provide lateral stability to the column during erection.  For the installation of this joist:

(a)  Provide a vertical stabilizer plate on each column for steel joists. The plate must be a minimum of 6 inches x 6 inches (15.2 cm x 15.2 cm), it must extend at least 3 inches (7.6 cm) below the bottom chord of the joist and have a thirteen-sixteenth (13/16) inch (2.1 cm) hole to provide an attachment point for guying or plumbing cables.

(b)  Stabilize the bottom chords of steel joists at columns to prevent rotation during erection.

(c)  Do not release hoisting cables until the seat at each end of the steel joist is field-bolted, and each end of the bottom chord is restrained by the column stabilizer plate.

(2)  Where constructability does not allow a steel joist to be installed at the column:

(a)  Install an alternate means of stabilizing joists on both sides near the column to provide stability equivalent to paragraph 28-8.s(1). The alternate means must be designed by a QP, be shop installed, and included in the erection drawings.

(b)  Do not release hoisting cables 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 feet (18.3 m) or less, design and erect the joist by either:

(a)  Installing bridging or otherwise stabilizing the joist prior to releasing the hoisting cable.

(b)  Releasing the cable without having a worker on the joist.

(4)  Where steel joists at or near columns span more than 60 feet (18.3 m), set the joists in tandem with all bridging installed, unless a QP designs an alternative method of erection with equivalent stability to the steel joist, and includes it in the site-specific Steel Erection Plan.

(5)  Do not place a steel joist or steel joist girder on any support structure unless such structure is stabilized.

(6)  When steel joist(s) are landed on a structure, secure them to prevent unintentional displacement prior to installation.

(7)  Do not make any modification that affects the strength of a steel joist or steel joist girder without the approval of the project structural engineer of record.

(8)  Field-Bolted Joists.

(a)  Except for steel joists that have been pre-assembled into panels, fabricate connections of individual steel joists to steel structures in bays of 40 feet (12.2 m) or more to allow for field bolting during erection.

(b)  Field-bolt these connections unless constructability does not allow.

(9)  Do not use steel joists or steel joist girders as anchorage points for a personal fall arrest system unless a QP provides written approval.

(10)  Establish a bridging terminus point before bridging is installed.

t. Attachment of steel joists and steel joist girders.  (28-8.t)

(1) Attach each end of "K" series steel joists to the support structure with a minimum of two 1/8 inch (0.3 cm) fillet welds that are 2½ inches (6.35 cm) long, or with two one-half (½) inch (1.3 cm) bolts, or the equivalent.

(2) Attach each end of "LH" and "DLH" series steel joists and steel joist girders to the support structure with a minimum of two one-quarter (¼) inch (0.6 cm) fillet welds 2 inches (5.1 cm) long, or with two three-quarter (¾) inch (1.9 cm) bolts, or the equivalent.

(3)  Except as provided in (4) below, attach each steel joist to the support structure immediately upon placement in the final erection position and before placing additional joists.

(4) Attach panels that have been pre-assembled from steel joists with bridging to the structure at each corner before releasing the hoisting cables.

u.  Erection of steel joists.  (28-8.u)

(1) Attach both sides of the seat of one end of each steel joist that requires bridging to the support structure before releasing the hoisting cables.  See tables 28-1 and 28-2 for bridging requirements.

(2)  For joists over 60 feet (18.3 m), attach both ends of the joist as specified in paragraph 24-8.t and incorporate the provisions of paragraph 28-8.v before releasing the hoisting cables.

(3)  On steel joists that do not require erection bridging as specified in tables 28-1 and 28-2, allow only one employee on the joist until all bridging is installed and anchored.

(4)  Do not allow employees 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.  Follow the requirements of paragraph 28-8 v.

(5)  When permanent bridging terminus points cannot be used during erection, install additional temporary bridging terminus points to provide stability.