ocument o evision calc-110 0 - castle - about us · 1.1 references ... asce 7-10. american society...

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SAMPLE PROJECT IN WASHINGTON DC

DOCUMENT NO. REVISION

CALC-110 0 TITLE Pages

LOADS AND LOAD COMBINATIONS 9

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SAMPLE PROJECT IN WASHINGTON DC TITLE REVISION PAGES

LOADS AND LOAD COMBINATIONS 2 of 9


Table of contents

1 Basic Data ....................................................................................... 3

1.1 References ....................................................................................... 3

2 Loads .............................................................................................. 4

2.1 Live load (L) ..................................................................................... 4

2.2 Wind load (W) .................................................................................. 4

2.3 Cladding wind load on South Elevation ............................................ 8

3 Load combinations ........................................................................ 9

3.1 Factored load combinations – Allowable stress design .................... 9

3.2 Factored load combinations - Strength design ................................. 9

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1 Basic Data

1.1 References

1.1.1 Norms and Standards

[1] ASCE 7-10. American Society of Civil Engineers – Minimum Design Loads for Buildings and Other Structures.

1.1.2 Project documents

1.1.3 Drawings

[2] Murphy/Jahn Architects. S8.02 – Typical Details and Structural Notes. 18 May 2012

[3] Murphy/Jahn Architects. A1.115 – Roof Plan. 18 May 2012

[4] Murphy/Jahn Architects. A3.104 – Elevation West. 18 May 2012

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2 Loads

2.1 Live load (L)

Barrier load to curtain wall according to ASCE 7-10 clause 4.5,

HL = 0.73 kN/m at 1067 mm above FFL

Vertical concentrated load to maintenance walkway according to ASCE 7-10 Table 4-1,

VL = 1.33 kN over an area of 0.58 m2

BMU socket restraint load,

HLm = 1.0 kN in any direction

2.2 Wind load (W)

Wind load calculation to ASCE 7-10 for components and cladding of partially enclosed building with occupancy category II on an exposure B terrain.

V = 51 m/s Basic wind speed

Kzt = 1.00 Velocity pressure exposure coefficient

Kd = 0.85 Wind directionality factor

h = 54.1 m

Kh =2.01(54.1/365.76)2/7 = 1.16 Topographic factor [Table 30.3-1]

qh =0.613·1.16·1.0·0.85·512 = 1.57 kN/m2 Velocity pressure [Cl.30.3.2]

Roof Plan

∼ 40 m

∼ 21 m

∼ 37 m

∼ 51 m

∼ 67 m

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Partial elevation

z = 48.5 m

h = 54.1 m

z = 40.7 m

z = 9 m

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2.2.1 Wind load to main curtain wall

A = 0.762m×3.20m = 2.44 m2 Wind area considered

(GCp)+/- = ±0.18 Internal pressure coefficient [Table 26.6-1]

i Positive pressure (Zone 4 & 5)

z = 48.5 m

Kz =2.01(48.5/365.76)2/7 = 1.13 Topographic factor [Table 30.3-1]

qz =0.613·1.13·1.0·0.85·512 = 1.53 kN/m2 Velocity pressure [Cl.30.3.2]

(GCp)+ = 0.9578 - 0.2146·log(2.44)= +0.87 External pressure coefficient [Fig.30.6-1]

p+ = 1.53(+0.87) – 1.57(-0.18) = +1.61 kN/m2 Cladding general pressure [Cl.30.6.2]

ii Non-corner negative pressure (Zone 4)

(GCp)- = 0.1431·log(2.44) - 0.9385= -0.88 External non-corner pressure coefficient [Fig.30.6-1]

p- = 1.57[-0.88 – (+0.18)] = -1.66 kN/m2 Cladding general suction [Cl.30.6.2]

iii Corner negative pressure (Zone 5)

a = max{0.1·37; 0.9} = 4.0 m Local corner zone

(GCp)- = 0.5723·log(2.44) – 1.9541= -1.73 External corner pressure coefficient [Fig.7.2-13]

p- = 1.57[-1.73 – (+0.18)] = -3.00 kN/m2 Cladding corner suction [Cl.7.2.10.4.2]

2.2.2 Wind load to mechanical level




z = h = 54.1 m

(GCp)+ = +0.9 External pressure coefficient [Fig.30.6-1]

p+ = 1.57[-0.9 – (+0.18)] = +1.70 kN/m2 Cladding general pressure [Cl.30.6.2]


(GCp)- = -0.9 External non-corner pressure coefficient [Fig.30.6-1]


iii Corner negative pressure (Zone 5)


(GCp)- = -1.8 External corner pressure coefficient [Fig.7.2-13]

p- = 1.57[-1.8 – (+0.18)] = -3.11 kN/m2 Cladding corner suction [Cl.7.2.10.4.2]

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2.2.3 Wind load to external skin glazing (non-corner)

Wind load to the non-corner area of the open-jointed point-fixed external skin glazing is calculated considering a partially enclosed building:

Ao > 1.1Aoi

Ao > min{ 0.37 m2; 0.01Ag}; Aoi/Agi ≤ 0.20




z = 40.7 m

Kz =2.01(40.7/365.76)2/7 = 1.07 Topographic factor [Table 30.3-1]

qz =0.613·1.07·1.0·0.85·512 = 1.45 kN/m2 Velocity pressure [Cl.30.3.2]


p+ = 1.45[+0.74 – (-0.55)] = +1.87 kN/m2 Cladding general pressure [Cl.30.6.2]


(GCp)- = 0.1431·log(9.8) - 0.9385= -0.80 External non-corner pressure coefficient [Fig.30.6-1]


2.2.4 Wind load to external skin glazing (corner)

Wind load to the corner area of the open-jointed point-fixed external skin glazing is calculated considering parapet loading according to the procedures of ASCE 7-10 clause 30.9:


i Corner negative pressure (Zone 5)



(GCp)- = 0.5723·log(9.8) – 1.9541= -1.39 External corner pressure coefficient [Fig.7.2-13]

p- = 1.45[-1.39 – (+0.74)] = +/- 3.09 kN/m2 Cladding corner suction [Cl.7.2.10.4.2]

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2.3 Cladding wind load on South Elevation

Wind loads for Ultimate Limit State Design*

Note: *Use reduction factor of 0.6 to determine wind loads for allowable stress design.

+/- 3.09 kN/m2

+1.87 kN/m2 -1.96 kN/m2 +

1.6

1 k

N/m

2

-3.0

0 k

N/m

2

+1.6

1 k

N/m

2

-3.0

0 k

N/m

2

+1.6

1 k

N/m

2

-3.0

0 k

N/m

2

+1.61 kN/m2 -1.66 kN/m2

+1.61 kN/m2 -1.66 kN/m2

+1.70 kN/m2 -1.70 kN/m2

+1.70 kN/m2 -3.11 kN/m2

+/-

3.0

9 k

N/m

2

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3 Load combinations

Load combinations for vertical cladding are in accordance with ASCE 7-10 [1].

3.1 Factored load combinations – Allowable stress design

Combination Description

CO100 (D) Dead load*

CO101 (D) + 0.6(Wp) Dead + wind pressure loads

CO102 (D) + 0.6(Ws) Dead + wind suction loads

CO103 (D) + (L) Dead + imposed loads

CO104 (D) + 0.75·0.6(Ws) + 0.75(L) Dead + wind suction + imposed loads

CO104 (D) + 0.75·0.6(Ws) + 0.75(L) Dead + wind suction + imposed loads

Note: *This includes permanent attachments and structural member selfweights.

3.2 Factored load combinations - Strength design

Combination Description

CO200 1.4(D) Dead load*

CO201 1.2(D) + 1.0(Wp) Dead + wind pressure loads

CO202 1.2(D) + 1.0(Ws) Dead + wind suction loads

CO203 1.2(D) + 1.6(L) Dead + live loads

CO204 1.2(D) + 1.0(Ws) + 0.5(L) Dead + wind suction + live loads

Note: *This includes permanent attachments and structural member selfweights.

ocument o evision calc-110 0 - castle - about us · 1.1 references ... asce 7-10. american society...

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