Eng : DW

Chk : ZM

Date : 2015-09-10

Calculation Sheet Rev : 0

1 of 2

GIRT DESIGN - C CHANNEL

Girt design based on Code Abbreviation

CSA-S16-09 Limit States Design of Steel Structures CSA-S16-09

AISC Design Guide 7: Industrial Buildings-Roofs to Anchor Rods 2nd Ed AISC Design Guide 7

Assumptions Code Reference

1. Girt is simply supported at building column grids

2. Girt exterior flange is laterally fully supported by wall cladding when cladding is subjected

to pressure load AISC Design Guide 7

3. Sag rods are assumed to provide lateral restraint against buckling when cladding is subjected page 17

to suction load

4. Girt and wall caldding self-weight are supported by sag rods hanging from roof eave strut beam

and thus no minor axis bending is considered in girt design

Input

Building importance category Normal

Wind pressure q 1/50 q = 0.40 [kPa] NBC10 Comment I

Reference height h = 2.000 [m] Fig I-7 Note (5)

Ce = 0.90 For open terrain NBC10 4.1.7.1 (5)

Iw = 1.00 For importance category Normal building NBC10 Table 4.1.7.1

NBC10 Comment I

Building category - internal pressure Category 3 Page I-22 Para. 31

Internal pressure coefficient - Cpi = -0.70 + Cpi = 0.70

Internal gust factor Cgi = 2.0 NBC10 4.1.7.1 (6)(c.)

Girt size C230x20

Girt span L = 7.620 [m]

No of sag rod in the span ngrt = 2

Girt spacing Sgrt = 1.981 [m]

Conclusion

[The Girt Section Is Adequate for Applied Force] ratio = 0.65

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Building Purlin C12X20.7 - 2 Tie Rod

Eng : DW

Chk : ZM

Date : 2015-09-10

Calculation Sheet Rev : 0Subject :

0

0

0

Project :

Job No :

Doc No :

Building Purlin C12X20.7 - 2 Tie Rod

2 of 2

Design Check Code Reference

External Surface Pressure NBC10 Comment I

Tributary area A = L x Sgrt = 15.10 [m2] Fig I-8

External pressure +CpCg = 1.75 - 0.26487 log A = 1.44

External suction -CpCg = -2.10 + 0.35312 log A = -1.68

Internal Surface Pressure

Internal pressure +CpiCgi = = 1.40 Page I-22 Para. 31

Internal suction -CpiCgi = = -1.40

Case 1 girt on windward side (external pressure + internal suction)

Wind pressure on cladding p = Iw q Ce [ +CpCg - (-CpiCgi) ] = 1.02 [kPa]

Linear load on girt w = p x Sgrt = 2.02 [kN/m]

Factored moment Mfx = (1.4w) x L2 / 8 = 20.6 [kNm]

Girt exterior flange is laterally fully supported by wall cladding when cladding is subjected to pressure load

Lu = = 0.0 [m]

Girt flexure C230x20 ratio = 0.44 OK

Girt deflection ∆ULS = (5 w L4) / (384 E Ix ) = 22.4 [mm] NBC 05

∆SLS = ∆ULS / Iw (ULS) x Iw (SLS) = 16.8 [mm] Table 4.1.7.1

∆ a = L / 180 = 42.3 [mm]

ratio = 0.40 OK

Case 2 girt on leeward side (external suction + internal pressure)

Wind pressure on cladding p = Iw q Ce [ -CpCg - (+CpiCgi) ] = -1.11 [kPa]

Linear load on girt w = p x Sgrt = 2.20 [kN/m]

Factored moment Mfx = (1.4w) x L2 / 8 = 22.3 [kNm]

Sag rods are assumed to provide lateral restraint against buckling when cladding is subjected to suction load

Girt unsupported length Lu = L / (ngrt +1) = 2.540 [m]

Girt flexure C230x20 ratio = 0.65 OK

Girt deflection ∆ULS = (5 w L4) / (384 E Ix ) = 24.4 [mm] NBC 05

∆SLS = ∆ULS / Iw (ULS) x Iw (SLS) = 18.3 [mm] Table 4.1.7.1

∆ a = L / 180 = 42.3 [mm]

ratio = 0.43 OK

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