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Vukazich CE 160 Dead Load Notes [L4] 1

CE 160 Notes - Dead Load Dead Load – Fixed position gravity load Dead Loads are calculated from tables of weights of building materials (similar to Table 2.1 in text or in AISC steel construction manual) and are usually computed in psf (lb/ft2) Dead Load Table

Use tables of weights of building materials (e.g. AISC Manual of Steel Construction) Convenient to work in unit weight (psf)

Load Path →

Material To metal

deck To beams (W14x22)

To girders, truss

(Lines 1-3) To columns

1-1/2” 18 gauge metal deck

2.82 (A) 2.82 2.82 2.82

Fireproofing 0.5 0.5 0.5 0.5

2” Rigid fiberglass insulation

3 (B) 3 3 3

3 ply felt tar and gravel roofing

5.5 (B) 5.5 5.5 5.5

Ceiling and Lighting

1 (B) 1 1 1

W14x22 @ 6 ft o.c. 3.7 (C) 3.7 3.7 Mechanical (plumbing, HVAC)

4 4 4

W18x50, truss 4 4 Weight of columns 1 Misc. 3 3 3 3 Total 15.82 23.52 27.52 28.52 Use 16 psf 24 psf 28 psf 29 psf Notes:

A. From Vulcraft deck catalog. B. From AISC steel manual “Weights of Building Materials”. C. W14x22: (22 lb/ft)/(6 ft) = 3.7 psf.

Vukazich CE 160 Dead Load Notes [L4] 2

Vukazich CE 160 Dead Load Notes [L4] 3

Lab #4 Problem

1. For our example steel building, using the uniform roof dead load table, draw the

idealization of the following members: A. One of the W14x22 beams between lines A and B (assume simple beam

connections can be idealized as a pin at one end and roller at the other); B. The W18x50 girder on line 2 between lines B and C (assume simple beam

connections can be idealized as a pin at one end and roller at the other); C. The truss on line 1 (as shown below, assume that the columns provide

supports that can be idealized as a pin at one end and roller at the other);

A

B

C

D

1 2 3

22’-0” 22’-0” 1’-6” 1’-6” 1’-6”

18’-0”

18’-0”

18’-0”

1’-6”

6’-0” typ. W14x22

W14x22

W18x65

W14x22

W14x22

W18x65

W14x22

W14x22

W18x65

W18x65 W14x22

W14x22

DO

DO

DO

DO

DO

DO

DO

DO

W18

x50

W18

x50

W18

x50

W18

x50

W18

x50

W18

x50

W18

x50

Dbl

6x6

Vukazich CE 160 Dead Load Notes [L4] 4

2. For the idealization of the truss found in 1C, use the method of sections to find

the truss member force in the members indicated in the figure above.

A B C 18’-0” 18’-0”

6’-0” typ.

4’-0”

Findtheaxialforceinthesemembers