Strap

Yield

Strap

Design Lat Defl Applied Elastic Defl

Design

Allow

Panel Panel Strap Strap

Strap

Initial Lat Stress Lat Yield

Shear

at Strap

Story Lateral Amp Import Story Stability Story

Width Height Faces Width

Thickness Stiffness of Strap Capacity Strength Yielding Shear

Defl Factor Factor Drifts

Coeff

Drifts

φQsy

∆a

ns

bs

ts

ks

Fsy

Qsy

VxS

Cd

δy

δe

∆

θ

W

H

I

t

s

x

(in)

(in)

(#)

(in)

(ga)

(in)

(k/in)

(ksi)

(k)

(k)

(in)

(kips)

(in)

(in)

(in)

3rd Floor

132 101.5

1

4

14 0.0747

41

33

7.8

7.4

0.239

6.71

0.205

3.5

1.0

0.718 0.0008

2.03

3rd Floor*

132 101.5

2

4

18 0.0478

53

33

10.0

9.5

0.239

6.71

0.160

3.5

1.0

0.561 0.0006

2.03

2nd Floor

140 113.5

2

6

14 0.0747

112

33

23.0

21.8

0.264

18.52

0.213

3.5

1.0

0.745 0.0015

2.27

1st Floor

140 109.5

2

6

12 0.1046

161

33

32.6

31.0

0.257

24.38

0.192

3.5

1.0

0.672 0.0020

2.19

1st Floor*

140 109.5

2

8

14 0.0747

154

33

31.1

29.5

0.257

24.38

0.201

3.5

1.0

0.705 0.0021

2.19

1st Floor

140 109.5

2

6

14 0.0747

115

50

35.3

33.5

0.389

24.38

0.269

3.5

1.0

0.94

0.0029

2.19

Increases in design story drift, ∆ related to P-delta effects are now evaluated. P-delta effects do not

need to be considered if the stability coefficient, θ is equal to or less than 0.10. The stability

coefficient, θ is defined in Equation C-30 and values are given in Table D-5. These values are well

below 0.10, so design story drifts do not need to be increased. Values of design story drifts, ∆ must

be less than the allowable story drifts, ∆a given in Table 3-2. For the barracks building this may be

expressed as follows (from Table 3-2):

∆a = 0.020H

(Eq D-22)

Values of design story drift, ∆ and allowable story drift, ∆a are given in Table D-5 for each floor level

for the trial panels in the short direction of the barracks building. The values in Table D-5 show that

design story drifts fall below allowable drifts by almost a factor of 3. Therefore these trial sizes meet

the drift requirements.

D10. COLUMN DESIGN. Columns are either built-up from studs (Panel A configuration) or are

structural tubes (Panel D). The columns built up with cold-formed steel studs must have the studs

oriented to form a closed cross-section as shown on Drawings A1 and A2 in Appendix B. Individual

studs must be welded to each other with a weld thickness equal to the thickness of the studs. The

welds are intermittent, with a length and spacing that will ensure composite behavior of the columns.

Structural tubing columns consist of a single tube, which is a closed section by itself. This column will

provide greater moment resistance because of the heavier anchorage detail, and will provide a

greater degree of structural redundancy and widening of the shear panel hysteretic performance.

a. Column Applied Loads. Total load applied to the entire building in the short direction is

expressed by Equation C-17, where the effects of gravity load and seismic forces are additive and

diagonal strap overstrength is accounted for. In this example snow loads, S are zero. This equation

can be expressed in terms of the total dead load, DT, and live load, L, given in Table D-2, as follows:

(1.2 + 0.2SDS )DT + 0.5L + Ω 0QE

(Eq D-23)

The loads expressed in Equation D-23 are now divided between the number of frames that make up

the short-direction lateral-load-resisting system. The barracks building has a total of nine such

frames. The loads are distributed based on the tributary area of each frame. Because the end bays

have only half the tributary area, the loads are divided by the number of frames minus one, or also

stated as the number of bays as seen in Table D-6. The vertical load resisting members are the

shear panel columns and individual studs, and these are distributed fairly uniformly in plan throughout

the building. It is assumed that vertical loads are distributed to these studs in proportion to their area,

because of the uniform distribution of columns and individual studs in throughout the building in plan

(normally gravity loads would be distributed based on tributary area).

6

Asterisk designates selected straps.

D-8

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