Client: 1 of 4
Cypress 01/08/18
Job:
Overhead Support Wire.mcdx
Dayton Cutoff Solar Farm
Overhead Support Wire
Lines:
(1) 5/16" High Tensile Steel wHT ≔ 0.205 ⋅ dHT ≔ 0.3125 nHT ≔ 1 DcHT ≔ 0.3125
Messenger Wire
(8) 600kcmil AL PV-wire wPV ≔ 0.756 dPV ≔ 1.096 nPV ≔ 8 DcPV ≔ 4.384
(4) #3 bare CU wCU ≔ 0.162 dCU ≔ 0.26 nCU ≔ 4 DcCU ≔ 0.52
(~95) CAB hangers wCAB ≔ 0.24 dCAB ≔ 0.25 nCAB ≔ 1 DcCAB ≔ 0.25
(Assume CAB hangers are one
continous line 1/4" thick) Dc is based on combined
cable arrangement and
engineering judgement
Geometry:
Length L ≔ 95
Height (Sag at mid span) h≔4
Height of Pole z ≔ 15
Length of cable with Sag
L ⎛ ‾‾‾‾‾‾
4h L ⎛ 4 ⋅ h ⎞⎞
Lsag ≔ ―⎜ 1 + ―― + ―― ⋅ sinh ⎜―― ⎟⎟ = 99.07
2 ⎝ L 4h ⎝ L ⎠⎠
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Client: 2 of 4
Cypress 01/08/18
Job:
Overhead Support Wire.mcdx
Dayton Cutoff Solar Farm
Dead Load:
D ≔ wHT ⋅ nHT + wPV ⋅ nPV + wCU ⋅ nCU + wCAB ⋅ nCAB
D = 7.14
Site Loading:
Wind Speed V ≔ 120 mph
Exposure C
Wind Force
Wind Factors
Exposure Category Kz ≔ 0.85
Topographic Factor Kzt ≔ 1.0
Wind Directional Kd ≔ 0.85
qz ≔ 0.00256 ⋅ ⋅ Kz ⋅ Kzt ⋅ Kd ⋅ V 2 = 26.63 (ASCE7-10 29.3-1)
Wind Pressure
Af ≔ DcHT + DcPV + DcCU + DcCAB = 0.46
G ≔ 0.85 Cf ≔ 1.0
Fh1 ≔ qz ⋅ G ⋅ Cf ⋅ Af = 10.31 (ASCE7-10 29.5-1)
Fhmin ≔ 16 ⋅ Af = 7.29 (ASCE7-10 29.3-1)
W ≔ ⎛⎝Fh1 < Fhmin , Fhmin , Fh1⎞⎠ (ASCE7-10 29.8)
W = 10.31
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Client: 3 of 4
Cypress 01/08/18
Job:
Overhead Support Wire.mcdx
Dayton Cutoff Solar Farm
Ice Thickness tice ≔ 0.5 (ASCE7-10 FIG10-5)
Density of Ice dice ≔ 56 (ASCE7-10 10.4.1)
Combined Wind Speed Vice ≔ 30 mph (ASCE7-10 FIG10-5)
Importance Factor Ii ≔ 0.8 (ASCE7-10 FIG10-5)
Weight of Ice
Height factor
⎛ z ⎞ 0.10
⎜ ―⎟
fz ≔ ⎜―― ⎟ = 0.92 fzi ≔ ⎛⎝z ≤ 33 , 1 , fz⎞⎠ = 1 (ASCE7-10 10.4-4)
⎜⎝ 33 ⎟⎠
(ASCE7-10 10.4-5)
Design Ice Thickness td ≔ 2 ⋅ tice ⋅ Ii ⋅ fz ⋅ Kzt 0.35 = 0.74
Volume of Ice
AiHT ≔ ⋅ td ⋅ ⎛⎝DcHT + td⎞⎠ = 0.02 2 (ASCE7-10 10.4-1)
AiPV ≔ ⋅ td ⋅ ⎛⎝DcPV + td⎞⎠ = 0.08 2 (ASCE7-10 10.4-1)
AiCU ≔ ⋅ td ⋅ ⎛⎝DcCU + td⎞⎠ = 0.02 2 (ASCE7-10 10.4-1)
AiCAB ≔ ⋅ td ⋅ ⎛⎝DcCAB + td⎞⎠ = 0.02 2 (ASCE7-10 10.4-1)
Weight of Ice on lines
Di ≔ dice ⋅ ⎛⎝AiHT + AiPV + AiCU + AiCAB⎞⎠ Di = 7.61
Wind on Ice
Wind Loading w/ ice
Wind Speed Vice = 30 mph
Exposure C
Wind Force
Wind Factors (see above)
qzi ≔ 0.00256 ⋅ ⋅ Kz ⋅ Kzt ⋅ Kd ⋅ Vice 2 = 1.66 (ASCE7-10 29.3-1)
Wind Pressure
Afi ≔ ⎛⎝DcHT + 2 ⎛⎝td⎞⎠⎞⎠ + ⎛⎝DcPV + 2 ⎛⎝td⎞⎠⎞⎠ + ⎛⎝DcCU + 2 ⎛⎝td⎞⎠⎞⎠ + ⎛⎝DcCAB + 2 ⎛⎝td⎞⎠⎞⎠ = 0.95
G ≔ 0.85 Cfi ≔ 1.2
(ASCE7-10 29.5-1)
Wi ≔ qzi ⋅ G ⋅ Cfi ⋅ Afi = 1.61
Wi = 1.61
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Client: 4 of 4
Cypress 01/08/18
Job:
Overhead Support Wire.mcdx
Dayton Cutoff Solar Farm
Load Cases:
Load Case 1: DL LC1 ≔ D = 7.14
Load Case 2: DL+Di LC2 ≔ D + Di = 14.75
Load Case 3: DL+0.7Di+0.7Wi LC3 ≔ D + 0.7 ⋅ Di + 0.7 ⋅ Wi = 13.59
Load Case 5: DL+0.6W LC5 ≔ D + 0.6 ⋅ W = 13.33
Load Case 7: 0.6DL+0.7Di+0.7Wi LC7 ≔ 0.6 ⋅ D + 0.7 ⋅ Di + 0.7 ⋅ Wi = 10.74
Max uniform load based on ASD load cases
wo ≔ max ((LC1 , LC2 , LC3 , LC5 , LC7)) = 14.75
Max Horizontal Force at Pole
wo ⋅ Lsag 2
FH ≔ ――― = 4524.02
8h
Max Tension in Wire
wo ⋅ Lsag ‾‾‾‾‾‾‾‾‾
⎛ Lsag ⎞ 2
Tmax ≔ ―――⋅ 1 + ⎜―― ⎟ = 4582.64
2 ⎝4h⎠
Safety Factor
SF ≔ 2
SF ⋅ Tmax = 9165.28
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