the 3rd floor shear panels. For the other shear panels the resistance factors are above 0.75, but are

judged to be acceptable because of the ATSM requirement on Fu/Fy.

Strap Tension Tension Design

Achieved

Fillet

Longitudinal Weld

Long/Trans Weld

Welded

Yield

/Shear

Net

Rupture Resistance

Weld

Design

Design

Conn Total

Force Net Area

Area

Strength

Factor

Thickness Length

Strength

Length

Strength

Capacity

φ

Psy

Anvt

Ant

(VT+T)ns

PL

PLT

(PL+PLT)ns

L

t

L

a

(in2)

(in2)

(kips)

(kips)

(in)

(in)

(kips)

(kips)

(kips)

3rd Floor

9.9

0.218

0.028

6.8

1.082

3rd Floor*

12.6

0.044

0.134

11.5

0.825

2nd Floor

29.6

0.153

0.269

26.4

0.840

1st Floor

41.4

0.312

0.259

34.3

0.906

1st Floor*

39.4

0.288

0.299

35.7

0.828

1st Floor

44.8

0.0747

6.25

12.5

8.75

21.4

67.9

c. Welded Connection Design. Figure D-9 shows a trial layout of a welded diagonal strap-to-

column connection. All welds in this connection have a thickness, t equal the thickness of the

diagonal strap (0.075 inches). This is much less than 0.15 inches, so weld failure through the weld

throat (Equation C-57) need not be considered. Details on the strap and column sizing are given in

the last row of Tables D-5 and D-8. All welds have a L/t ratio much greater than 25, so that Equation

C-55 is used to define the longitudinal weld capacity. The top edge of this connection shown in

Figure D-9 is loaded in the longitudinal direction and its design shear strength is defined according to

Equation C-55. The diagonal edges at the end of the diagonal strap are loaded close to 45 degrees,

so that an average of Equation C-55 and C-56 defines the weld capacity along these edges.

Therefore, the longitudinal/transverse design shear strength (PLT) may be expressed as follows:

PLT = 0.87φLFu

t

(Eq D-28)

Where:

φ= 0.58, which is an average of the resistance factors for longitudinal and transverse loading

expressed in Equations C-55 and C-56.

Table D-13 gives the weld thickness, length of welds loaded in the longitudinal and

longitudinal/transverse directions. Table D-13 also gives the design capacity of the longitudinal,

longitudinal/transverse and combined capacity ((PL + PLT)ns) expressed by Equation 3-21, as modified

by Equation D-28. Comparing the total shear capacity and strap yield strength, Psy shows that this

connection detail meets the requirements of Equation 3-21.

D12. SHEAR PANEL ANCHORS. Panel anchors must be installed on both sides of the shear panel

columns. These anchors are installed at both the top and bottom of the columns to anchor the panels

to the floor diaphragms both above and below the shear panels. The anchors are needed to provide

the required shear, uplift and moment resistance from the eccentric diagonal strap loading of the

anchors. The anchors will also provide limited moment resistance that will allow some moment frame

action of the columns, providing system redundancy and a widening of the hysteretic load/deflection

envelope. The anchors consist of angle iron sections welded to the column, with loose steel plates

that are both bolted to the diaphragm using embedded anchor bolts (see Figures D4 through D9).

a. Anchor Shear Capacity. All of the trial columns shown in Table D-8 have insufficient

shear capacity by themselves and require additional shear capacity from their anchorage. The

anchor angle irons increase the shear capacity. Each angle leg extends beyond the critical shear

plane. Figure D-4 shows such an anchorage made up with 6 inch long, L 4 x 4 x inch angle iron

sections welded to both sides of each column. The anchor shear capacity is defined according to

Equation 3-22, and the combined column and anchor shear capacity is defined according to Equation

D-14

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