37988564 asce 7 98 code wind loading analysis

"ASCE798W" --- ASCE 7-98 CODE WIND ANALYSIS PROGRAM

Program Description:

"ASCE798W" is a spreadsheet program written in MS-Excel for the purpose of wind loading analysis for buildings

and structures per the ASCE 7-98 Code. Specifically, wind pressure coefficients and related and required

parameters are selected or calculated in order to compute the net design wind pressures.

This program is a workbook consisting of eight (8) worksheets, described as follows:

Worksheet Name DescriptionDoc This documentation sheet

Simplified Analysis using simplified method for low-rise buildings with h <= 30’

MWFRS (Low-Rise) Main Wind-Force Resisting System for low-rise buildings with h <= 60’

MWFRS (Any Ht.) Main Wind-Force Resisting System for buildings of any height

Wall C&C Analysis of wall Components and Cladding

Roof C&C Analysis of roof Components and Cladding

Stacks & Tanks Analysis of cantilevered chimneys, stacks, and vertical tanks

Wind Map Basic wind speed map (Figure 6-1 of ASCE 7-98 Code)

Program Assumptions and Limitations:

1. This program assumes only enclosed or partially enclosed buildings. Open buildings are NOT considered.

2. Worksheet for Simplified analysis is applicable for buildings meeting the criteria of Section 6.4.1.

3. In the worksheet for Simplified analysis, the design MWFRS wind load is calculated for each direction.

This design load is assumed equal to 1/2 of the total load, as 1/2 is assumed to be taken at roof level and

the other 1/2 is taken at the base of the building.

4. Worksheet for MWFRS (Low-Rise) is applicable for low-rise buildings as defined in Section 6.2.

5. Worksheets for MWFRS (Any Ht.), Wall C&C, and Roof C&C are applicable for buildings with mean roof

heights of up to 500 feet.

6. Worksheet for Stacks & Tanks is applicable for cantilevered structures up to 600 feet tall.

7. Worksheets for Wall C&C and Roof C&C are applicable for flat roof buildings, gable roof buildings with roof

angles <= 45 degrees, and monoslope roof buildings with roof angles <= 3 degrees.

8. Worksheets for MWFRS (Any Ht.) and for Stacks & Tanks can handle “rigid” as well as “flexible” buildings

and structures. For “rigid” buildings or structures, this program uses the smaller value of either 0.85 or the

calculated value from Section 6.5.8.1 of the Code for the gust effect factor, 'G'. For “flexible” buildings or

structures, this program calculates the gust effect factor, ‘Gf’, per Section 6.5.8 of the Code based on the

assumed formula for the fundamental period of vibration from Section 9.5.3.3 of the Code.

9. This program uses the equations listed in the reference, “Guide to the Use of the Wind Load Provisions of

ASCE 7-98” for determining the external wind pressure coefficients, ‘GCp’, used in the Wall C&C and Roof

C&C worksheets.

10. This program contains numerous “comment boxes” which contain a wide variety of information including

explanations of input or output items, equations used, data tables, etc. (Note: presence of a “comment box”

is denoted by a “red triangle” in the upper right-hand corner of a cell. Merely move the mouse pointer to the

desired cell to view the contents of that particular "comment box".)

"ASCE798W.xls" ProgramVersion 2.9

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WIND LOADING ANALYSIS - Main Wind-Force Resisting System

Using Method 1: Simplified Procedure (Section 6.4)Job Name: Subject: ###

Job Number: Originator: Checker: ######

Input Data: ######

Wind Speed, V = 130 mph (Wind Map, Fig. 6-1) ###Bldg. Classification = II (Table 1-1) ###Exposure Category = C (Sect. 6.5.6) (Do not use Exp. "A") ###

Ridge Height, hr = 15.00 ft. (hr >= he) ###Eave Height, he = 15.00 ft. (he <= hr) ###

Building Width = 30.00 ft. (Normal to Building Ridge) IBuilding Length = 60.00 ft. (Parallel to Building Ridge) II

Roof Type = Monoslope (Gable or Monoslope) Plan IIIEnclosed? (Y/N) Y (Sect. 6.2 & Table 6-7) IV

MWFRS Trib. Area = 1800.00 ft.^2 ARoof C&C Name = Joist (Purlin, Joist, Decking, or Fastener) B

Roof C&C Area = 300.00 ft.^2 (for Component/Cladding) CWall C&C Name = Wall (Girt, Siding, Wall, or Fastener) D

Wall C&C Area = 75.00 ft.^2 (for Component/Cladding) GableMonoslope

Resulting Parameters and Net Design Pressures: YElevation N

0.00 deg. PurlinMean Roof Ht., h = 15.00 Joist

DeckingMWFRS Net Pressures Design MWFRS Load Fastener

Location p (psf) GirtRoof -36.96 (Width) (Length) SidingWalls 40.60 9.13 18.27 Wall

FastenerComponents & Cladding Net Pressures ###

Location Zone +p (psf) -p (psf) ###1 14.00 -39.20 Roof

Roof Joist 2 14.00 -46.20 ###3 14.00 -46.20 ###

Wall 4 37.49 -41.61 ###5 37.49 -46.90 ###

###Notes: 1. Design wind pressures are net pressures (sum of external and internal pressures). ###

2. Wall net pressure for MWFRS is total for both windward and leeward walls. Walls3. (+) and (-) signs signify wind pressures acting toward & away from respective surfaces. ###4. Net pressures taken from Tables 6-2, 6-3A and 6-3B and include the following "multipliers": ###

Exposure Factor = 1.40 ###Area Reduction Factor = 0.80

Importance Factor, I = 1.005. Wall & Roof End Zone Widths for Components & Cladding: a = 3.00 ft.

Components & Cladding for Enclosed Building:7. References: a. ASCE 7-98, "Minimum Design Loads for Buildings and Other Structures". Roof:

b. "Guide to the Use of the Wind Load Provisions of ASCE 7-98" 2(+) =

Per ASCE 7-98 Code for Low-Rise Buildings with h <= 30' and Roof q < 10o

Roof Angle, q =ft. (h = he for q < 10 deg.)

SP (kips) SP (kips)

6. Minimum wind load for MWFRS and C&C shall not be less than 10 psf.

q<10o

Width

Length

Width

hr

heh<=30'

C9

The Basic Design Wind Speed, V (mph), corresponds to a 3-second gust speed at 33' above ground in Exposure Category "C" and is associated with an annual probability of 0.02 of being equalled or exceeded (50-year mean recurrence interval). For Basic Wind Speed Map (Fig. 6-1) see 'Wind Map' worksheet of this workbook.

C10

TABLE 1-1 Classification of Buildings and Other Structures for Flood, Wind, Snow, and Earthquake Loads Nature of Occupancy Category Buildings and structures that represent a low hazard to human life in the event of failure including, but not limited to: I - Agriculture Facilities - Certain Temporary Facilities - Minor Storage Facilities All buildings and other structures except those listed in Categories I, III & IV II Buildings and other structures that represent a substantial hazard to human life in the event of failure including, but not limited to: III - Buildings and other structures where more than 300 people congregate in one area - Buildings and other structures with day-care facilities with a capacity greater than 150 - Buildings and other structures with elementary school or secondary school facilities with a capacity greater than 250 - Colleges & adult education facilities with a capacity greater than 500 - Health care facilities with a capacity greater than 50 resident patients but not having surgery or emergency treatment facilities - Jails and detention facilities - Power generating stations and other public utility facilities not included in Category IV - Buildings and structures containing sufficient quantities of toxic, explosive or other hazardous substances known to be dangerous to the public if released but not limited to: - Petrochemical and fuel storage facilities - Manufacturing or storage facilities for hazardous chemicals or explosives Buildings and other structures that are equipped with secondary containment of toxic, explosive or other hazardous substances (including, but not limited to dbl wall tank, dike of sufficient size to contain a spill, or other means to contain a spill or a blast within the property boundary of the facility and prevent release of harmful quantities of contaminants to the air, soil, ground, or surface water) or atmosphere (where appropriate) shall be eligible for classification as a Category II structure. This reduced classification shall not be permitted for seismic loads. In hurricane prone regions, buildings and other structures that contain toxic, explosive, or other hazardous substances and do not qualify as Category IV structures shall be eligible for classification as Category II structures for wind loads if these structures are operated in accordance with mandatory procedures that are acceptable to the authority having jurisdiction and which effectively diminish the effects of wind on critical structural elements or which alternatively protect against harmful releases during and after hurricanes. Buildings and other structures designated as essential facilities including, but not limited to: IV - Hospitals and health care facilities having surgery or emergency treatment facilities - Fire, rescue and police stations and emergency vehicle garages - Designated earthquake, hurricane or other emergency shelters - Communication centers and other facilities required for emergency response - Power-generating stations and other public utility facilities required in an emergency - Ancillary structures (including but not limited to communication towers, fuel storage tanks, cooling towers, electrical substation structures, fire water storage tanks or other structures housing or supporting water or other fire suppression material or equipment) required for operation of Category IV structures during an emergency. - Aviation control towers, air traffic control centers and emergency aircraft hangars - Water storage facilities and pump structures required to maintain water pressure for fire suppression. - Buildings and other structures having critical national defense functions

C11

Exposure Categories adequately reflect the characteristics of ground surface irregularities at the building site. Exposure Categories are as follows: Exposure "A": Large city centers with at least 50% of the buildings having a height in excess of 70'. Use of this exposure category is limited to those areas for which terrain representative of Exposure "A" prevails in the upwind direction for a distance >= 0.5 miles or 10 times the height of the building or other structure, whichever is greater. Exposure "B": Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger. Use of this exposure category is limited to those areas for which terrain representative of Exposure "B" prevails in the upwind direction for a distance >= 1,500' or 10 times the height of the building or other structure, whichever is greater. Exposure "C": Open terrain with scattered obstructions having heights generally less than 30'. This category includes flat open country, grasslands and shorelines in hurricane prone regions. Exposure "D": Flat, unobstructed areas exposed to wind flowing over open water (excluding shorelines in hurricane prone regions) for a distance of at least 1 mile. Shorelines in Exposure D include inland waterways, the Great Lakes and coastal areas of California, Oregon, Washington and Alaska. This exposure applies only to those buildings exposed to the wind coming from over the water. Exposure "D" extends inland from the shoreline a distance >= 1,500' or 10 times the height of the building or other structure, whichever is greater.

C16

This program assumes that a Gable roof is symmetrical, as the ridge line is assumed in the center of the building width, L. For flat roofs (roof angle = 0 degrees), either Gable (G) or Monoslope (M) may be used.

C17

This worksheet assumes either Enclosed or Partially Enclosed buildings, and does not consider open buildings. 1. An enclosed building is a building that does not comply with the requirements for open or partially enclosed buildings. 2. An open building is a structure having all walls at least 80% open. 3. A partially enclosed building complies with both of the following conditions: a. the total area of openings in a wall that receives positive external pressure exceeds the sum of the areas of the openings in the balance of the building envelope (walls and roof) by more than 10%; and b. the total area of openings in a wall that receives positive external pressure exceeds 4 sq ft or 1% of the area of that wall, whichever is smaller, and the % of openings in balance of the building envelope does not exceed 20%.

C18

The Tributary Area pertaining to the Main Wind-Force Resisting System (MWFRS).

C20

The Effective Area, for a component or cladding panel equals the span length times the effective width that need not be less than 1/3 of the span length; however, for a fastener it is the area tributary to an individual fastener. Note: Major structural components supporting tributary areas > 700 sq ft shall be permitted to be designed using the provisions for main wind-force resisting systems (MWFRS).

C22

The Effective Area, for a component or cladding panel equals the span length times the effective width that need not be less than 1/3 of the span length; however, for a fastener it is the area tributary to an individual fastener. Note: Major structural components supporting tributary areas > 700 sq ft shall be permitted to be designed using the provisions for main wind-force resisting systems (MWFRS).

C27

For buildings with roof angle <= 10 degrees: h = he (per Sect. 6-3).

E32

For calculating the sum of the wind load on the windward and leeward walls parallel to the building ridge, the average roof height = (hr+he)/2 is used.

J45

The following values were used in developing the net pressures in Tables 6-2, 6-3A, and 6-3B: h = 30 ft. Exposure B Kz= 0.70 Kd = 0.85 G = 0.85 Kzt = 1.0 I = 1.0 GCpi =(+/-)0.18 (enclosed building) GCpi = (+/-)0.55 (partially enclosed building) Cp (pressure coefficients) from Figures 6-3 and 6-5

E46

Exposure Factor B 1.00 C 1.40 D 1.66

E47

Area Reduction Factor (ft.^2) (Interpolation Permitted) <= 100 1.0 250 0.9 >= 1000 0.8 Note: above factors are applicable to MWFRS pressures for roof only.

E48

Importance Factor, I (Table 6-1): Non-Hurricane Prone Regions Hurricane Prone Regions Category and Hurricane Prone Regions with V > 100 mph with V = 85-100 mph and Alaska I 0.87 0.77 II 1.00 1.00 III 1.15 1.15 IV 1.15 1.15

H49

Width 'a' is equal to 10% of least horizontal dimension or 0.4*h, whichever is smaller, but not less than either 4% of least horizontal dimension or 3'.


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by: Kishor C. Mehta and Dale C. Perry (2002). 3(+) =


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WIND LOADING ANALYSIS - Main Wind-Force Resisting SystemPer ASCE 7-98 Code for Enclosed or Partially Enclosed Buildings

Using Method 2: Analytical Procedure (Section 6.5) for Low-Rise BuildingsJob Name: Subject: II

Job Number: Originator: Checker: IIIIV

Input Data: AB

Wind Speed, V = 90 mph (Wind Map, Fig. 6-1) CBldg. Classification = II (Table 1-1) DExposure Category = C (Sect. 6.5.6) Gable

Ridge Height, hr = 53.33 ft. (hr >= he) MonoslopeEave Height, he = 20.00 ft. (he <= hr) Y

Building Width = 200.00 ft. (Normal to Building Ridge) NBuilding Length = 250.00 ft. (Parallel to Building Ridge) Roof Zone 3E =

Roof Type = Gable (Gable or Monoslope) Wall Zone 4E =Topo. Factor, Kzt = 1.00 (Sect. 6.5.7)Direct. Factor, Kd = 0.85 (Table 6-6)

Enclosed? (Y/N) Y (Sect. 6.2 & Table 6-7) For Case 'A':0.5*L =2.5*h =

Resulting Parameters and Coefficients: Use =

18.43 deg. External Pressure Coeffients, GCpf (Fig. 6-4):Mean Roof Ht., h = 36.67 ft. (h = (hr+he)/2, for angle >10 deg.) For Case 'B':

Wall Zone 1 =Check Criteria for a Low-Rise Building: Roof Zone 2 =

1. Is h <= 60' ? Yes, O.K. 2. Is h <= Lesser of L or B? Yes, O.K. Roof Zone 3 =Wall Zone 4 =

External Pressure Coeff's., GCpf (Fig. 6-4): Wall Zone 5 =(For values, see following wind load tabulations.) Wall Zone 6 =Positive & Negative Internal Pressure Coefficients, GCpi (Table 6-7): Wall Zone 1E =

+GCpi Coef. = 0.18 (positive internal pressure) Roof Zone 2E =-GCpi Coef. = -0.18 (negative internal pressure) Roof Zone 3E =

Wall Zone 4E =Wall Zone 5E =Wall Zone 6E =

9.50 (Table 6-4)zg = 900 (Table 6-4)Kh = 1.02 (Kh = Kz evaluated at z = h) Lesser of L or B:

I = 1.00 (Table 6-1) (Importance factor) 0.1*(L or B):Compare to 0.4*h:

Velocity Pressure: qz = 0.00256*Kz*Kzt*Kd*V^2*I (Sect. 6.5.10, Eq. 6-13) Compare to .04*(L, B):qh = 18.06 psf qh = 0.00256*Kh*Kzt*Kd*V^2*I (qz evaluated at z = h)Compare to 3':

Design Net External Wind Pressures (Sect. 6.5.12.2.2): Use 'a' =p = qh*[(GCpf) - (+/-GCpi)] (psf, Eq. 6-16) Use '2*a' =

Wall and Roof End Zone Widths 'a' and '2*a' (Fig. 6-4):a = 14.67 ft.

2*a = 29.33 ft.

Roof Angle, q =

If h < 15 then: Kh = 2.01*(15/zg)^(2/a) (Table 6-5, Case 1b)If h >= 15 then: Kh = 2.01*(z/zg)^(2/a) (Table 6-5, Case 1b)

a =

q o

L

B

hr

heh<=60'

Wind

Plan

Elevation

L

B9


B10


B11


B16


B17

The Topographic Factor, Kzt, accounts for effect of wind speed-up over isolated hills and escarpments (Sect. 6.5.7 and Fig. 6-2). Kzt = (1+K1*K2*K3)^2 (Eq. 6-1), where: H = height of hill or escarpment relative to the upwind terrain, in feet. Lh = Distance upwind of crest to where the difference in ground elevation is half the height of hill or escarpment, in feet. K1 = factor to account for shape of topographic feature and maximum speed-up effect. K2 = factor to account for reduction in speed-up with distance upwind or downwind of crest. K3 = factor to account for reduction in speed-up with height above local terrain. x = distance (upwind or downwind) from the crest to the building site, in feet. z = height above local ground level, in feet. The effect of wind speed-up shall not be required to be considered (Kzt = 1.0) when H/Lh < 0.2, or H < 15' for Exposures 'C' and 'D', or H < 60' for Exposures 'A' and 'B'.

B18

Wind Directionality Factor, Kd (Table 6-6) Structure Type Kd Buildings Main Wind-Force Resisting System 0.85 Components and Cladding 0.85 Note: this factor shall only be applied when used in conjunction with load combinations specified in Sect. 2.3 and 2.4. Otherwise, use Kd = 1.0.

B19


B25

The building Mean Roof Height, h, is determined as follows: For buildings with roof angle > 10 degrees: h = (hr+he)/2 For buildings with roof angle <= 10 degrees: h = he

C27

For an enclosed or partially enclosed building to be classified as a Low-Rise building, the following 2 conditions must both be met: 1. The building mean roof height, h, must be <= 60 ft. 2. The building mean roof height, h, does not exceed the least horizontal dimension, L or B.

C30

External Pressure Coefficients, GCpf, for MWFRS ( Fig. 6-4): Roof Case A Angle,q Building Surface (Zone) (deg.) 1 2 3 4 1E 2E 3E 4E 0-5 0.40 -0.69 -0.37 -0.29 0.61 -1.07 -0.53 -0.43 20 0.53 -0.69 -0.48 -0.43 0.80 -1.07 -0.69 -0.64 30-45 0.56 0.21 -0.43 -0.37 0.69 0.27 -0.53 -0.48 90 0.56 0.56 -0.37 -0.37 0.69 0.69 -0.48 -0.48 Roof Case B Angle, q Building Surface (Zone) (deg.) 1 2 3 4 5 6 1E 2E 3E 4E 5E 6E 0-90 -0.45 -0.69 -0.37 -0.45 0.40 -0.29 -0.48 -1.07 -0.53 -0.48 0.61 -0.43

E32

Internal Pressure Coefficients, GCpi (Table 6-7) Condition (+/-) GCpi Partially enclosed buildings +0.55, -0.55 Enclosed buildings +0.18, -0.18 Per Sect. 6.5.11.1, for a partially enclosed building containing a single, unpartitioned large volume, the GCpi coefficients shall be multiplied by the following reduction factor, Ri: Ri = 1.0 or Ri = 0.5*(1+(1/(1+Vi/(22800*Aog))^0.5)) <= 1.0 where: Aog = total area of openings in the building envelope (walls and roof, ft.^2). Vi = unpartitioned internal volume (ft.^3). Note: This program assumes NO reduction of the GCpi coefficients for large volume buildings. Thus, Ri = 1.0.

C38

Terrain Exposure Constants (Table 6-4) Exposure Category a zg (ft) A 5.0 1,500 B 7.0 1,200 C 9.5 900 D 11.5 700

C41


D45

Per Code Section 6.1.4.1, the minimum wind load to be used in the design of the Main Wind-Force Resisting System shall not be less than 10 psf.

D48

Width 'a' is equal to 10% of least horizontal dimension or 0.4*h, whichever is smaller, but not less than either 4% of least horizontal dimension or 3'.


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+GCpi Coef. (PIP) =


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MWFRS Wind Load Tabulation for Case 'A' Case 'A' Rotated (Corner II)Surface GCpf p = Net Pressures (psf) Surface *GCpf p = Net Pressures (psf)

(w/ +GCpi) (w/ -GCpi) (w/ +GCpi) (w/ -GCpi)Zone 1 0.52 6.08 12.58 Zone 1 0.40 3.97 10.47Zone 2 -0.69 -15.71 -9.21 Zone 2 -0.69 -15.71 -9.21Zone 3 -0.47 -11.71 -5.21 Zone 3 -0.37 -9.93 -3.43Zone 4 -0.42 -10.75 -4.25 Zone 4 -0.29 -8.49 -1.99

Zone 1E 0.78 10.84 17.34 Zone 1E 0.61 7.77 14.27Zone 2E -1.07 -22.57 -16.07 Zone 2E -1.07 -22.57 -16.07Zone 3E -0.67 -15.41 -8.91 Zone 3E -0.53 -12.82 -6.32Zone 4E -0.62 -14.41 -7.91 Zone 4E -0.43 -11.02 -4.51

For Case 'A' when GCpf is neg. in Zone 2: For Case 'A' rot. when GCpf is neg. in Zone 2:Zone 2 distance = 91.66 ft. Zone 2 distance = 91.66 ft.

Remainder of roof Zone 2 to have roof Zone 3 pressures.

MWFRS Wind Load Tabulation for Case 'B' Case 'B' Rotated (Corner II)Surface GCpf p = Net Pressure (psf) Surface GCpf p = Net Pressure (psf)

(w/ +GCpi) (w/ -GCpi) (w/ +GCpi) (w/ -GCpi)Zone 1 -0.45 -11.38 -4.88 Zone 1 -0.45 -11.38 -4.88Zone 2 -0.69 -15.71 -9.21 Zone 2 -0.69 -15.71 -9.21Zone 3 -0.37 -9.93 -3.43 Zone 3 -0.37 -9.93 -3.43Zone 4 -0.45 -11.38 -4.88 Zone 4 -0.45 -11.38 -4.88Zone 5 0.40 3.97 10.47 Zone 5 0.40 3.97 10.47Zone 6 -0.29 -8.49 -1.99 Zone 6 -0.29 -8.49 -1.99

Zone 1E -0.48 -11.92 -5.42 Zone 1E -0.48 -11.92 -5.42Zone 2E -1.07 -22.57 -16.07 Zone 2E -1.07 -22.57 -16.07Zone 3E -0.53 -12.82 -6.32 Zone 3E -0.53 -12.82 -6.32Zone 4E -0.48 -11.92 -5.42 Zone 4E -0.48 -11.92 -5.42Zone 5E 0.61 7.77 14.27 Zone 5E 0.61 7.77 14.27Zone 6E -0.43 -11.02 -4.51 Zone 6E -0.43 -11.02 -4.51

Notes: 1. For Case 'A', Case 'A' Rotated (90 deg.), Case 'B', and Case 'B' Rotated (90 deg.): Zone 1 is windward wall for interior zone. Zone 1E is windward wall for end zone. Zone 2 is windward roof for interior zone. Zone 2E is windward roof for end zone. Zone 3 is leeward roof for interior zone. Zone 3E is leeward roof for end zone. Zone 4 is leeward wall for interior zone. Zone 4E is leeward wall for end zone. Zone 5 is sidewall for interior zone. Zone 5E is sidewall for end zone. Zone 6 is sidewall for interior zone. Zone 6E is sidewall for end zone. 2. (+) and (-) signs signify wind pressures acting toward & away from respective surfaces.

4. References : a. ASCE 7-98, "Minimum Design Loads for Buildings and Other Structures". b. "Guide to the Use of the Wind Load Provisions of ASCE 7-98" by: Kishor C. Mehta and Dale C. Perry (2002).

*Note: Use roof angle q = 0 degrees for Case 'A' rotated.

3. Per Code Section 6.1.4.1, the minimum wind load for MWFRS shall not be less than 10 psf.

C66

For load Case A the roof pressure coefficient, GCpf, when negative in Zone 2, shall be applied in Zone 2 for a distance from the edge of the roof equal to 0.5 times the horizontal dimension of the building measured perpendicular to the eave line or 2.5*h, whichever is less; the remainder of Zone 2 extending to the ridge line shall use the pressure coefficient GCpf for Zone 3.

H66

For load Case A the roof pressure coefficient, GCpf, when negative in Zone 2, shall be applied in Zone 2 for a distance from the edge of the roof equal to 0.5 times the horizontal dimension of the building measured perpendicular to the eave line or 2.5*h, whichever is less; the remainder of Zone 2 extending to the ridge line shall use the pressure coefficient GCpf for Zone 3.


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MWFRS Zones and Load Cases for Low-Rise Buildings:

FIGURE C6-2. Application of Load Cases for Two Windward Corners


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WIND LOADING ANALYSIS - Main Wind-Force Resisting SystemPer ASCE 7-98 Code for Enclosed or Partially Enclosed Buildings

Using Method 2: Analytical Procedure (Section 6.5) for Buildings of Any HeightJob Name: Subject:

Job Number: Originator: Checker:

Input Data:

Wind Direction = Normal (Normal or Parallel to building ridge)Wind Speed, V = 120 mph (Wind Map, Fig. 6-1)

Bldg. Classification = II (Table 1-1)Exposure Category = B (Sect. 6.5.6)

Ridge Height, hr = 157.00 ft. (hr >= he)Eave Height, he = 157.00 ft. (he <= hr)

Building Width = 100.00 ft. (Normal to Building Ridge)Building Length = 200.00 ft. (Parallel to Building Ridge)

Roof Type = Monoslope (Gable or Monoslope)Topo. Factor, Kzt = 1.00 (Sect. 6.5.7)Direct. Factor, Kd = 0.85 (Table 6-6)

Enclosed? (Y/N) Y (Sect. 6.2 & Table 6-7)0.030 (Suggested Range = 0.010-0.070)

Period Coef., Ct = 0.0200 (Suggested Range = 0.020-0.035)(Assume: T = Ct*h^(3/4) , and f = 1/T)

Resulting Parameters and Coefficients:

0.00 deg.Mean Roof Ht., h = 157.00 ft. (h = he, for roof angle <=10 deg.) L = 100 ft.

Windward Wall Cp = 0.80 (Fig. 6-3) B = 200 ft.Leeward Wall Cp = -0.50 (Fig. 6-3)

Side Walls Cp = -0.70 (Fig. 6-3)Roof Cp (zone #1) = -1.04 (Fig. 6-3) (zone #1 for 0 to h/2)Roof Cp (zone #2) = -0.70 (Fig. 6-3) (zone #2 for h/2 to h)Roof Cp (zone #3) = N.A. (Fig. 6-3) (zone #3 for h to 2*h)Roof Cp (zone #4) = N.A. (Fig. 6-3) (zone #4 for > 2*h)

+GCpi Coef. = 0.18 (Table 6-7) (positive internal pressure)-GCpi Coef. = -0.18 (Table 6-7) (negative internal pressure)

7.00 zg = 1200 (Table 6-4)Kh = 1.12 (Kh = Kz evaluated at z = h)

I = 1.00 (Table 6-1) (Importance factor)Velocity Pressure: qz = 0.00256*Kz*Kzt*Kd*V^2*I (Sect. 6.5.10, Eq. 6-13)

qh = 35.23 psf qh = 0.00256*Kh*Kzt*Kd*V^2*I (qz evaluated at z = h)Ratio h/L = 1.570 freq., f = 1.127 hz. (f >= 1, Rigid structure)

Gust Factor, G = 0.818 (Sect. 6.5.8)Design Net External Wind Pressures (Sect. 6.5.12.2):p = qz*G*Cp - qi*(+/-GCpi) for windward wall (psf), where: qi =qh (Eq. 6-15, Sect. 6.5.12.2.1)p = qh*G*Cp - qi*(+/-GCpi) for leeward wall, sidewalls, and roof (psf), where: qi = qh (Sect. 6.5.12.2.1)

Damping Ratio, b =

Roof Angle, q =

If z <= 15 then: Kz = 2.01*(15/zg)^(2/a) , If z > 15 then: Kz = 2.01*(z/zg)^(2/a) (Table 6-5, Case 2a)a =

q o

L

B

hr

heh

Plan

Elevation

L

Wind

B9

Actual values of B and L depend on the Wind Direction, and are defined as follows: B = horizontal dimension of building measured normal to wind direction. L = horizontal dimension of building measured parallel to wind direction. Note: Plan view at right depicts case where Wind Direction is Normal to building ridge.

B10


B11


B12


B17


B18


B19


B20


B21

The Damping Ratio, b, is the percent of critical damping. It is only used in the calculation of the Gust Factor, Gf, when a building is considered "flexible". A building is considered "flexible" when it has a natural frequency, f < 1 hz. Otherwise the building is considered "rigid". Suggested range of values is from 0.010 to 0.070 as indicated below: Material/Construction b (Damping Ratio) Welded steel, 0.01 to 0.02 prestressed concrete Reinforced concrete 0.03 to 0.05 Bolted or riveted steel, 0.05 to 0.07 wood Note: if the building is "flexible", the smaller the value of the damping ratio, the larger the gust effect factor, Gf, becomes.

B22

The building Period Coefficient, Ct, has suggested range of values from 0.020 to 0.035. It is used in the equation for the assumed period of the building: T = Ct*h^3/4. Then the natural frequency, f, is determined by: f = 1/T. It is only used in the calculation of the Gust Factor, Gf, when a building is considered "flexible". A building is considered "flexible" when it has a natural frequency, f < 1 hz. Otherwise the building is considered "rigid". Note: if the period, T, or the natural frequency, f, is already known (obtained by other means), then the value of Ct may be "manipulated" to give the desired results for T and f.

B29


G29

Note: 'L' is the horizontal dimension of the building measured parallel to the wind direction.

C30

Wall External Pressure Coefficients, Cp (Fig. 6-3) Surface L/B Cp Use With Windward All values 0.8 qz Wall Leeward 0-1 -0.5 Wall 2 -0.3 qh >=4 -0.2 Side Walls All values -0.7 qh

G30

Note: 'B' is the horizontal dimension of the building measured normal to the wind direction.

C33

Roof External Pressure Coefficients, Cp, for Use with qh (Fig. 6-3): Windward Leeward Wind Angle, q (degrees) Angle, q (degrees) Direction h/L 10 15 20 25 30 35 45 10 15 >=20 <=0.25 -0.7 -0.5 -0.3 -0.2 -0.2 0.0 0.0 -0.3 -0.5 -0.6 Normal to 0.0 0.0 0.2 0.3 0.3 0.4 0.4 ridge for 0.5 -0.9 -0.7 -0.4 -0.3 -0.2 -0.2 0.0 -0.5 -0.5 -0.6 q>=10 0.0 0.0 0.0 0.2 0.2 0.3 0.4 >=1.0 -1.3** -1.0 -0.7 -0.5 -0.3 -0.2 0.0 -0.7 -0.6 -0.6 0.0 0.0 0.0 0.0 0.2 0.2 0.3 Horiz. dist. from Normal to windward edge Cp *Value is provided for interpolation purposes. ridge for 0 to h/2 -0.9 **Value can be reduced linearly with area over which q<10 & <=0.5 h/2 to h -0.9 it is applicable as follows: Area Reduction Parallel to h to 2*h -0.5 (sq ft) Factor ridge for >2*h -0.3 <=100 1.0 all q >=1.0 0 to h/2 -1.3** 250 0.9 >h/2 -0.7 >=1000 0.8

C37


E41


C43


D48



11 of 33 04/09/2023 19:44:19

Normal to Ridge Wind Load Tabulation for MWFRS - Buildings of Any HeightSurface z Kz qz Cp p = Net Design Press. (psf)

(ft.) (psf) (w/ +GCpi) (w/ -GCpi)Windward Wall 0 0.57 18.01 0.80 5.45 18.13

15.00 0.57 18.01 0.80 5.45 18.1320.00 0.62 19.55 0.80 6.46 19.1425.00 0.67 20.84 0.80 7.30 19.9830.00 0.70 21.95 0.80 8.03 20.7135.00 0.73 22.94 0.80 8.68 21.3640.00 0.76 23.83 0.80 9.26 21.9445.00 0.79 24.65 0.80 9.80 22.4850.00 0.81 25.40 0.80 10.29 22.9755.00 0.83 26.10 0.80 10.75 23.4360.00 0.85 26.76 0.80 11.18 23.8670.00 0.89 27.97 0.80 11.97 24.6580.00 0.93 29.05 0.80 12.68 25.3690.00 0.96 30.05 0.80 13.33 26.01

100.00 0.99 30.97 0.80 13.93 26.61120.00 1.04 32.62 0.80 15.01 27.70140.00 1.09 34.09 0.80 15.98 28.66

For z = hr: 157.00 1.12 35.23 0.80 16.72 29.40

For z = he: 157.00 1.12 35.23 0.80 16.72 29.40For z = h: 157.00 1.12 35.23 0.80 16.72 29.40

Leeward Wall All - - -0.50 -20.75 -8.07Side Walls All - - -0.70 -26.52 -13.84

Roof (zone #1) - - - -1.04 -36.32 -23.64Roof (zone #2) - - - -0.70 -26.52 -13.84

Notes: 1. (+) and (-) signs signify wind pressures acting toward & away from respective surfaces.


4. Roof zone #1 is applied for horizontal distance of 0 to h/2 from windward edge. 5. Roof zone #2 is applied for horizontal distance of h/2 to h from windward edge.

2. Per Code Section 6.1.4.1, the minimum wind load for MWFRS shall not be less than 10 psf.


12 of 33 04/09/2023 19:44:19

Determination of Gust Effect Factor, G:

Is Building Flexible? No f >=1 Hz.

G = 0.850

Parameters Used in Both Item #2 and Item #3 Calculations (from Table 6-4):0.143

b^ = 0.840.250

b(bar) = 0.45c = 0.30

320 ft.0.333

z(min) = 30 ft.

Calculated Parameters Used in Both Rigid and/or Flexible Building Calculations:z(bar) = 94.20 = 0.6*h , but not < z(min) , ft.

Iz(bar) = 0.252 = c*(33/z(bar))^(1/6) , Eq. 6-3

Lz(bar) = 453.94gq = 3.4 (3.4, per Sect. 6.5.8.1)gv = 3.4 (3.4, per Sect. 6.5.8.1)gr = 4.218 = (2*(LN(3600*f)))^(1/2)+0.577/(2*LN(3600*f))^(1/2) , Eq. 6-7Q = 0.805 = (1/(1+0.63*((B+h)/Lz(bar))^0.63))^(1/2) , Eq. 6-4

G = 0.818 = 0.925*((1+1.7*gq*Iz(bar)*Q)/(1+1.7*gv*Iz(bar))) , Eq. 6-2

0.030 Damping RatioCt = 0.020 Period CoefficientT = 0.887 = Ct*h^(3/4) , sec. (Period)f = 1.127 = 1/T , Hz. (Natural Frequency)

V(fps) = N.A. = V(mph)*(88/60) , ft./sec.

V(bar,zbar) = N.A.N1 = N.A. = f*Lz(bar)/(V(bar,zbar)) , Eq. 6-10

Rn = N.A. = 7.47*N1/(1+10.3*N1)^(5/3) , Eq. 6-9N.A. = 4.6*f*h/(V(bar,zbar))

Rh = N.A.N.A. = 4.6*f*B/(V(bar,zbar))

RB = N.A.N.A. = 15.4*f*L/(V(bar,zbar))

RL = N.A.R = N.A.

Gf = N.A. = 0.925*(1+1.7*Iz(bar)*(gq^2*Q^2+gr^2*R^2)^(1/2))/(1+1.7*gv*Iz(bar)) ,Use: G = 0.818 Eq. 6-6

1: Simplified Method for Rigid Building

a^ =

a(bar) =

l =e(bar) =

= l*(z(bar)/33)^(e(bar)) , Eq. 6-5

2: Calculation of G for Rigid Building

3: Calculation of Gf for Flexible Buildingb =

= b(bar)*(z(bar)/33)^(a(bar))*V*(88/60) , ft./sec. , Eq. 6-12

hh =

= (1/hh)-1/(2*hh^2)*(1-e^(-2*hh)) for hh > 0, or = 1 for hh = 0 ,Eq. 6-11 hB =

= (1/hB)-1/(2*hB^2)*(1-e^(-2*hB)) for hB > 0, or = 1 for hB = 0,Eq. 6-11 hL =

= (1/hL)-1/(2*hL^2)*(1-e^(-2*hL)) for hL > 0, or = 1 for hL = 0 ,Eq. 6-11 = ((1/b)*Rn*Rh*RB*(0.53+0.47*RL))^(1/2) , Eq. 6-8

B108

Buildings which have a natural frequency, f >= 1 Hz are considered "rigid". Buildings which have a natural frequency, f < 1 Hz are considered "flexible".

C110

The Gust Effect Factor, G, for rigid buildings may be simply taken as 0.85 for all building exposure conditions.

E113

Terrain Exposure Constants (Table 6-4) Exposure a zg(ft) a^ b^ a(bar) b(bar) c l(ft) e z(min) A 5.0 1500 1/5 0.64 1/3.0 0.30 0.45 180 1/2.0 60 B 7.0 1200 1/7 0.84 1/4.0 0.45 0.30 320 1/3.0 30 C 9.5 900 1/9.5 1.00 1/6.5 0.65 0.20 500 1/5.0 15 D 11.5 700 1/11.5 1.07 1/9.0 0.80 0.15 650 1/8.0 7 Note: z(min) = minimum height used to ensure that the equivalent height z(bar) is greater of 0.6*h or z(min). For buildings with h<= z(min), z(bar) shall be taken as z(min).

B124

The Equivalent Height of the Building, z(bar). z(bar) = 0.6*h but not less than z(min) from Table 6-4. where: h = building mean roof height

B125

The Intensity of Turbulence at height = z(bar). Iz(bar) = c*(33/z(bar))^(1/6)

B126

The Integral Length Scale of Turbulence at the equivalent height. Lz(bar) = l*(z(bar)/33)^(e (bar))

B127

Peak Factor for backround response: gq = 3.4 (per Sect. 6.5.8.1)

B128

Peak Factor for wind response: gv = 3.4 (per Sect. 6.5.8.1)

B129

Peak Factor for resonant response: gr = (2*(LN(3600*f)))^(1/2)+0.577/(2*LN(3600*f))^(1/2) Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B130

The Backround Response Factor, Q. Q = (1/(1+0.63*((B+h)/Lz(bar))^0.63))^(1/2) where: B = building width normal to wind h = building mean roof height

C132

The Gust Effect Factor, G, for a rigid building as calculated from Eqn. 6-2.

B133

The Gust Effect Factor, G, for a "rigid" structure. G = 0.925*((1+1.7*gq*Iz(bar)*Q)/(1+1.7*gv*Iz(bar))) where: gq = 3.4 and gv = 3.4

C135

The Gust Effect Factor, Gf, for a flexible building as calculated from Eqn 6-6. Note: calculations below are applicable only for "flexible" buildings which have a natural frequency, f < 1 hz.

B140

The Basic Wind Speed, V, converted from units of mph to ft/sec. V(fps) = V(mph)*(88/60)

B141

The Mean Hourly Wind Speed, V(bar,zbar). V(bar,zbar) = b(bar)*(z(bar)/33)^(a(bar))*V*(88/60)

B142

N1 = f*Lz(bar)/(V(bar,zbar)) Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B143

Rn = 7.47*N1/(1+10.3*N1)^(5/3)

B144

hh = 4.6*f*h/(V(bar,zbar)) Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B145

Rh = (1/hh)-1/(2*hh^2)*(1-e^(-2*hh)) for hh > 0 or: Rh = 1 for hh = 0

B146

hb =4.6*f*b/(V(bar,zbar)) where: b = building width normal to wind Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B147

RB = (1/hB)-1/(2*hB^2)*(1-e^(-2*hB)) for hB > 0 or: RB = 1 for hB = 0

B148

hd = 15.4*f*L/(V(bar,zbar)) where: L = depth of building parallel to wind Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B149

RL = (1/hL)-1/(2*hL^2)*(1-e^(-2*hL)) for hL > 0 or: RL = 1 for hL = 0

B150

The Resonant Response Factor, R. R = ((1/b)*Rn*Rh*Rb*(0.53+0.47*Rd))^1/2

B151

The Gust Effect Factor, Gf, for a "flexible" building. Gf = 0.925*(1+1.7*Iz(bar)*(gq^2*Q^2+gr^2*R^2))^(1/2)/(1+1.7*gv*Iz(bar))

B152

For a rigid building, the smaller of the value of either 0.85 or the value as calculated in item #2 is used for the gust effect factor, G.


13 of 33 04/09/2023 19:44:19


14 of 33 04/09/2023 19:44:19

Wind Pressure Combinations for Full and Partial Loading of MWFRS for Buildings with h > 60 ft.

Case 1: Full design wind pressures acting on the projected area perpendicular to each principal axis of the building considered separately.Case 2: Wind pressure as defined in Case 1, but with a 25% reduction in pressure acting on 50% of the projected area bounded by the extreme projected edge of the building.Case 3: Wind pressure as defined in Case 1, but considered to act simultaneously at 75% of the specified value.Case 4: Wind pressure as defined in Case 3, but with a 25% reduction of these pressures acting on 50% of the projected area bounded by the extreme projected edge of the building.

Notes: 1. Design wind pressures for windward (Pw) and leeward (PL) faces are obtained from provisions for buildings with a mean roof height, h > 60 ft. (per Sect. 6.5.12). 2. Above diagrams show plan view of building. 3. Pw = Windward face design pressure , PL = Leeward face design pressure.


16 of 33 04/09/2023 19:44:20

WIND LOADING ANALYSIS - Wall Components and CladdingPer ASCE 7-98 Code for Buildings of Any Height

Using Method 2: Analytical Procedure (Section 6.5)Job Name: Subject: II


Input Data: AB



Building Width = 200.00 ft. (Normal to Building Ridge) NBuilding Length = 250.00 ft. (Parallel to Building Ridge) Girt

Roof Type = Gable (Gable or Monoslope) SidingTopo. Factor, Kzt = 1.00 (Sect. 6.5.7) WallDirect. Factor, Kd = 0.85 (Table 6-6) Fastener

Enclosed? (Y/N) Y (Sect. 6.2 & Table 6-7) Use 'a' =Component Name = Girt (Girt, Siding, Wall, or Fastener)Effective Area, Ae = 208

+GCpi Coef. (PIP) =-GCpi Coef. (NIP) =

Resulting Parameters and Coefficients:

18.43 deg.Mean Roof Ht., h = 36.67 ft. (h = (hr+he)/2, for roof angle >10 deg.) zg =

Kh =Wall External Pressure Coefficients, GCp: I =

GCp Zone 4 Pos. = 0.77 (Fig. 6-5A) qh =GCp Zone 5 Pos. = 0.77 (Fig. 6-5A)GCp Zone 4 Neg. = -0.87 (Fig. 6-5A)GCp Zone 5 Neg. = -0.93 (Fig. 6-5A)

Positive & Negative Internal Pressure Coefficients, GCpi (Table 6-7):+GCpi Coef. = 0.18 (positive internal pressure)-GCpi Coef. = -0.18 (negative internal pressure)

9.50 (Table 6-4)zg = 900 (Table 6-4)Kh = 1.02 (Kh = Kz evaluated at z = h)

I = 1.00 (Table 6-1) (Importance factor)Velocity Pressure: qz = 0.00256*Kz*Kzt*Kd*V^2*I (Sect. 6.5.10, Eq. 6-13)

qh = 18.06 psf qh = 0.00256*Kh*Kzt*Kd*V^2*I (qz evaluated at z = h)

Design Net External Wind Pressures (Sect. 6.5.12.4):For h <= 60 ft.: p = qh*((GCp) - (+/-GCpi)) (psf)For h > 60 ft.: p = q*(GCp) - qi*(+/-GCpi) (psf) where: q = qz for windward walls, q = qh for leeward walls and side walls qi = qh for all walls (conservatively assumed per Sect. 6.5.12.4.2)

ft.^2 (Area Tributary to C&C)

Roof Angle, q = a =


q o

L

B

hr

heh

Plan

Elevation

L

B9


B10


B11


B16


B17


B18


B19


B21

The Effective Area, Ae, for a component or cladding panel equals the span length times the effective width that need not be less than 1/3 of the span length. For a vertically spanning CMU or concrete wall, "Ae" equals the wall height squared divided by 3. For a fastener, the value of "Ae" equals the area tributary to an individual fastener. Note: Major structural components supporting tributary areas > 700 sq ft shall be permitted to be designed using the provisions for main wind-force resisting systems (MWFRS).

B27


C29

FIG. 6-5A - Walls for Buildings with h <= 60 ft. Positive: Zone 4 & 5 (GCp) = 1.0 for A <= 10 sq.ft. (GCp) = 1.1766-0.1766*logA for 10 < A <= 500 sq.ft. (GCp) = 0.7 for A > 500 sq.ft. Negative: Zone 4 (GCp) = -1.1 for A <= 10 sq.ft. (GCp) = -1.2766+0.1766*logA for 10 < A <= 500 sq.ft. (GCp) = -0.8 for A > 500 sq.ft. Negative: Zone 5 (GCp) = -1.4 for A <= 10 sq.ft. (GCp) = -1.7532+0.3532*logA for 10 < A <= 500 sq.ft. (GCp) = -0.8 for A > 500 sq.ft. FIG. 6-8 - Walls for Buildings with h > 60 ft. Positive: Zone 4 & 5 (GCp) = 0.9 for A <= 20 sq.ft. (GCp) = 1.1792-0.2146*logA for 20 < A <= 500 sq.ft. (GCp) = 0.6 for A > 500 sq.ft. Negative: Zone 4 (GCp) = -0.9 for A <= 20 sq.ft. (GCp) = -1.0861+0.1431*logA for 20 < A <= 500 sq.ft. (GCp) = -0.7 for A > 500 sq.ft. Negative: Zone 5 (GCp) = -1.8 for A <= 20 sq.ft. (GCp) = -2.5445+0.5723*logA for 20 < A <= 500 sq.ft. (GCp) = -1.0 for A > 500 sq.ft.

E34


C39


C42


D46



17 of 33 04/09/2023 19:44:20

Wind Load Tabulation for Wall Components & CladdingComponent z Kh qh p = Net Design Pressures (psf)

(ft.) (psf) Zone 4 (+) Zone 4 (-) Zone 5 (+) Zone 5 (-)Girt 0 1.02 18.06 17.11 -18.91 17.11 -20.13

15.00 1.02 18.06 17.11 -18.91 17.11 -20.1320.00 1.02 18.06 17.11 -18.91 17.11 -20.1325.00 1.02 18.06 17.11 -18.91 17.11 -20.1330.00 1.02 18.06 17.11 -18.91 17.11 -20.1335.00 1.02 18.06 17.11 -18.91 17.11 -20.1340.00 1.02 18.06 17.11 -18.91 17.11 -20.1345.00 1.02 18.06 17.11 -18.91 17.11 -20.1350.00 1.02 18.06 17.11 -18.91 17.11 -20.13

For z = hr: 53.33 1.02 18.06 17.11 -18.91 17.11 -20.13

For z = he: 20.00 1.02 18.06 17.11 -18.91 17.11 -20.13For z = h: 36.67 1.02 18.06 17.11 -18.91 17.11 -20.13

Notes: 1. (+) and (-) signs signify wind pressures acting toward & away from respective surfaces. 2. Width of Zone 5 (end zones), 'a' = 14.67 ft.


3. Per Code Section 6.1.4.2, the minimum wind load for C&C shall not be less than 10 psf.

E55

Positive (+) pressure applies to windward wall. Maximum positive pressure is evaluated using the positive (+) external wind pressure coefficient, '+GCp', in combination with the negative (-) internal pressure coefficient, '-GCpi'.

F55

Negative (-) pressure applies to leeward wall and side walls. Maximum negative pressure is evaluated using the negative (-) external wind pressure coefficient, '-GCp', in combination with the positive (+) internal pressure coefficient, '+GCpi'.

G55

Positive (+) pressure applies to windward wall. Maximum positive pressure is evaluated using the positive (+) external wind pressure coefficient, '+GCp', in combination with the negative (-) internal pressure coefficient, '-GCpi'.

H55

Negative (-) pressure applies to leeward wall and side walls. Maximum negative pressure is evaluated using the negative (-) external wind pressure coefficient, '-GCp', in combination with the positive (+) internal pressure coefficient, '+GCpi'.

F86

For h <= 60', width 'a' for Zone 5 is equal to 10% of least horizontal dimension or 0.4*h, whichever is smaller, but not less than either 4% of least horizontal dimension or 3'. For h > 60', width 'a' for Zone 5 is equal to 10% of least horizontal dimension, but not less than 3'.


18 of 33 04/09/2023 19:44:20

Wall Components and Cladding:

Wall Zones for Buildings with h <= 60 ft.

Wall Zones for Buildings with h > 60 ft.


19 of 33 04/09/2023 19:44:20

WIND LOADING ANALYSIS - Roof Components and Cladding

Using Method 2: Analytical Procedure (Section 6.5)Job Name: Subject: II


Input Data: AB



Building Width = 200.00 ft. (Normal to Building Ridge) NBuilding Length = 250.00 ft. (Parallel to Building Ridge) Purlin

Roof Type = Gable (Gable or Monoslope) JoistTopo. Factor, Kzt = 1.00 (Sect. 6.5.7) DeckingDirect. Factor, Kd = 0.85 (Table 6-6) Fastener

Enclosed? (Y/N) Y (Sect. 6.2 & Table 6-7) For Zone 1 Neg. =Component Name = Joist (Purlin, Joist, Decking, or Fastener) For Zone 2 Neg. =Effective Area, Ae = 208 For Zone 3 Neg. =

Overhangs? (Y/N) N (if used, overhangs on all sides) Use Zone 1,2,3 Pos. =Use Zone 1 Neg. =Use Zone 2 Neg. =

Resulting Parameters and Coefficients: Use Zone 3 Neg. =

18.43 deg.Mean Roof Ht., h = 36.67 ft. (h = (hr+he)/2, for roof angle >10 deg.) Fig. 6-5B:

Roof External Pressure Coefficients, GCp: For Zone 1,2,3 Pos. =GCp Zone 1-3 Pos. = 0.30 (Fig. 6-5B) For Zone 1 Neg. =

GCp Zone 1 Neg. = -0.80 (Fig. 6-5B) For Zone 2 Neg. =GCp Zone 2 Neg. = -1.40 (Fig. 6-5B) For Zone 3 Neg. =GCp Zone 3 Neg. = -1.40 (Fig. 6-5B)

Positive & Negative Internal Pressure Coefficients, GCpi (Table 6-7): For Zone 1,2,3 Pos. =+GCpi Coef. = 0.18 (positive internal pressure) For Zone 1 Neg. =-GCpi Coef. = -0.18 (negative internal pressure) For Zone 2 Neg. =

For Zone 3 Neg. =9.50

zg = 900 (Table 6-4) For Zone 1,2,3 Pos. =Kh = 1.02 (Kh = Kz evaluated at z = h) For Zone 1 Neg. =

I = 1.00 (Table 6-1) (Importance factor) For Zone 2 Neg. =Velocity Pressure: qz = 0.00256*Kz*Kzt*Kd*V^2*I (Sect. 6.5.10, Eq. 6-13) For Zone 3 Neg. =

qh = 18.06 psf qh = 0.00256*Kh*Kzt*Kd*V^2*I (qz evaluated at z = h)Use Zone 1,2,3 Pos. =Use Zone 1 Neg. =

Design Net External Wind Pressures (Sect. 6.5.12.4): Use Zone 2 Neg. =For h <= 60 ft.: p = qh*((GCp) - (+/-GCpi)) (psf) Use Zone 3 Neg. =For h > 60 ft.: p = q*(GCp) - qi*(+/-GCpi) (psf) where: q = qh for roof qi = qh for roof (conservatively assumed per Sect. 6.5.12.4.2)

Width 'a' for Zone 2 for h <= 60':Lesser of L or B:

Per ASCE 7-98 Code for Bldgs. of Any Height with Gable Roof q <= 45o or Monoslope Roof q <= 3o

ft.^2 (Area Tributary to C&C)

Roof Angle, q =


q o

L

B

hr

heh

Plan

Elevation

L

B9


B10


B11


B16


B17


B18


B19


B21

The Effective Area, Ae, for a component or cladding panel equals the span length times the effective width that need not be less than 1/3 of the span length; however, for a fastener it is the area tributary to an individual fastener. Note: Major structural components supporting tributary areas > 700 sq ft shall be permitted to be designed using the provisions for main wind-force resisting systems (MWFRS).

B28


E31

FIG. 6-5B - Roofs for Buildings with h <= 60 ft. For q <= 10: Positive without overhang: Zone 1,2,3 (GCp) = 0.3 for A <= 10 sq.ft. (GCp) = 0.4000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.2 for A > 100 sq.ft. Negative without overhang: Zone 1 (GCp) = -1.0 for A <= 10 sq.ft. (GCp) = -1.1000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.9 for A > 100 sq.ft. Negative without overhang: Zone 2 (GCp) = -1.8 for A <= 10 sq.ft. (GCp) = -2.5000+0.7000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative without overhang: Zone 3 (GCp) = -2.8 for A <= 10 sq.ft. (GCp) = -4.5000+1.7000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.1 for A > 100 sq.ft.

F31

FIG. 6-5B - Roofs for Buildings with h <= 60 ft. For q <= 10: Positive with overhang: Zone 1,2,3 (GCp) = 0.3 for A <= 10 sq.ft. (GCp) = 0.4000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.2 for A > 100 sq.ft. Negative with overhang: Zone 1 & 2 (GCp) = -1.7 for A <= 10 sq.ft. (GCp) = -1.8000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -3.0307+0.7153*logA for 100 < A <= 500 sq.ft. (GCp) = -1.1 for A > 500 sq.ft. Negative with overhang: Zone 3 (GCp) = -2.8 for A <= 10 sq.ft. (GCp) = -4.8000+2.0000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft.

G31

FIG. 6-8 - Roofs for Buildings with h > 60 ft. Note: for q > 10, use FIG. 6-5B For q <= 10: Negative without overhang: Zone 1 (GCp) = -1.4 for A <= 10 sq.ft. (GCp) = -1.6943-0.2943*logA for 10 < A <= 500 sq.ft. (GCp) = -0.9 for A > 500 sq.ft. Negative without overhang: Zone 2 (GCp) = -2.3 for A <= 10 sq.ft. (GCp) = -2.7120+0.4120*logA for 10 < A <= 500 sq.ft. (GCp) = -1.6 for A > 500 sq.ft. Negative without overhang: Zone 3 (GCp) = -3.2 for A <= 10 sq.ft. (GCp) = -3.7297+0.5297*logA for 10 < A <= 500 sq.ft. (GCp) = -2.3 for A > 500 sq.ft.

H31

FIG. 6-8 - Roofs for Buildings with h > 60 ft. Note: for all buildings with overhangs, use FIG. 6-5B For q <= 10: Positive with overhang: Zone 1,2,3 (GCp) = 0.3 for A <= 10 sq.ft. (GCp) = 0.4000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.2 for A > 100 sq.ft. Negative with overhang: Zone 1 & 2 (GCp) = -1.7 for A <= 10 sq.ft. (GCp) = -1.8000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -3.0307+0.7153*logA for 100 < A <= 500 sq.ft. (GCp) = -1.1 for A > 500 sq.ft. Negative with overhang: Zone 3 (GCp) = -2.8 for A <= 10 sq.ft. (GCp) = -4.8000+2.0000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft.

E32

FIG. 6-5B - Roofs for Buildings with h <= 60 ft. For 10 < q <= 30: Positive without overhang: Zone 1,2,3 (GCp) = 0.5 for A <= 10 sq.ft. (GCp) = 0.7000-0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.3 for A > 100 sq.ft. Negative without overhang: Zone 1 (GCp) = -0.9 for A <= 10 sq.ft. (GCp) = -1.0000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative without overhang: Zone 2 & 3 (GCp) = -2.1 for A <= 10 sq.ft. (GCp) = -2.8000+0.7000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.4 for A > 100 sq.ft.

F32

FIG. 6-5B - Roofs for Buildings with h <= 60 ft. For 10 < q <= 30: Positive with overhang: Zone 1,2,3 (GCp) = 0.5 for A <= 10 sq.ft. (GCp) = 0.7000-0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.3 for A > 100 sq.ft. Negative with overhang: Zone 1 (GCp) = -0.9 for A <= 10 sq.ft. (GCp) = -1.0000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative with overhang: Zone 2 & 3 (GCp) = -2.1 for A <= 10 sq.ft. (GCp) = -2.8000+0.7000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.4 for A > 100 sq.ft.

G32

FIG. 6-8 - Roofs for Buildings with h > 60 ft. Note: for q > 10, use FIG. 6-5B For 10 < q <= 30: Positive without overhang: Zone 1,2,3 (GCp) = 0.5 for A <= 10 sq.ft. (GCp) = 0.7000-0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.3 for A > 100 sq.ft. Negative without overhang: Zone 1 (GCp) = -0.9 for A <= 10 sq.ft. (GCp) = -1.0000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative without overhang: Zone 2 & 3 (GCp) = -2.1 for A <= 10 sq.ft. (GCp) = -2.8000+0.7000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.4 for A > 100 sq.ft.

H32

FIG. 6-8 - Roofs for Buildings with h > 60 ft. Note: for all buildings with overhangs, use FIG. 6-5B For 10 < q <= 30: Positive with overhang: Zone 1,2,3 (GCp) = 0.5 for A <= 10 sq.ft. (GCp) = 0.7000-0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.3 for A > 100 sq.ft. Negative with overhang: Zone 1 (GCp) = -0.9 for A <= 10 sq.ft. (GCp) = -1.0000+0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative with overhang: Zone 2 & 3 (GCp) = -2.1 for A <= 10 sq.ft. (GCp) = -2.8000+0.7000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.4 for A > 100 sq.ft.

E33

FIG. 6-5B - Roofs for Buildings with h <= 60 ft. For 30 < q <= 45: Positive without overhang: Zone 1,2,3 (GCp) = 0.9 for A <= 10 sq.ft. (GCp) = 1.0000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.8 for A > 100 sq.ft. Negative without overhang: Zone 1 (GCp) = -1.0 for A <= 10 sq.ft. (GCp) = -1.2000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative without overhang: Zone 2 & 3 (GCp) = -1.2 for A <= 10 sq.ft. (GCp) = -1.4000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.0 for A > 100 sq.ft.

F33

FIG. 6-5B - Roofs for Buildings with h <= 60 ft. For 30 < q <= 45: Positive with overhang: Zone 1,2,3 (GCp) = 0.9 for A <= 10 sq.ft. (GCp) = 1.0000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.8 for A > 100 sq.ft. Negative with overhang: Zone 1 (GCp) = -1.0 for A <= 10 sq.ft. (GCp) = -1.2000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative with overhang: Zone 2 & 3 (GCp) = -1.2 for A <= 10 sq.ft. (GCp) = -1.4000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.0 for A > 100 sq.ft.

G33

FIG. 6-5B - Roofs for Buildings with h > 60 ft. Note: for q > 10, use FIG. 6-5B For 30 < q <= 45: Positive without overhang: Zone 1,2,3 (GCp) = 0.9 for A <= 10 sq.ft. (GCp) = 1.0000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.8 for A > 100 sq.ft. Negative without overhang: Zone 1 (GCp) = -1.0 for A <= 10 sq.ft. (GCp) = -1.2000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative without overhang: Zone 2 & 3 (GCp) = -1.2 for A <= 10 sq.ft. (GCp) = -1.4000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.0 for A > 100 sq.ft.

H33

FIG. 6-8 - Roofs for Buildings with h > 60 ft. Note: for all buildings with overhangs, use FIG. 6-5B For 30 < q <= 45: Positive with overhang: Zone 1,2,3 (GCp) = 0.9 for A <= 10 sq.ft. (GCp) = 1.0000-0.1000*logA for 10 < A <= 100 sq.ft. (GCp) = 0.8 for A > 100 sq.ft. Negative with overhang: Zone 1 (GCp) = -1.0 for A <= 10 sq.ft. (GCp) = -1.2000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -0.8 for A > 100 sq.ft. Negative with overhang: Zone 2 & 3 (GCp) = -1.2 for A <= 10 sq.ft. (GCp) = -1.4000+0.2000*logA for 10 < A <= 100 sq.ft. (GCp) = -1.0 for A > 100 sq.ft.

E35


C40


C42


D46



20 of 33 04/09/2023 19:44:20

Wind Load Tabulation for Roof Components & CladdingComponent z Kh qh p = Net Design Pressures (psf)

(ft.) (psf) Zone 1,2,3 (+) Zone 1 (-) Zone 2 (-) Zone 3 (-)Joist 0 1.02 18.06 8.67 -17.70 -28.53 -28.53

15.00 1.02 18.06 8.67 -17.70 -28.53 -28.5320.00 1.02 18.06 8.67 -17.70 -28.53 -28.5325.00 1.02 18.06 8.67 -17.70 -28.53 -28.5330.00 1.02 18.06 8.67 -17.70 -28.53 -28.5335.00 1.02 18.06 8.67 -17.70 -28.53 -28.5340.00 1.02 18.06 8.67 -17.70 -28.53 -28.5345.00 1.02 18.06 8.67 -17.70 -28.53 -28.5350.00 1.02 18.06 8.67 -17.70 -28.53 -28.53

For z = hr: 53.33 1.02 18.06 8.67 -17.70 -28.53 -28.53

For z = he: 20.00 1.02 18.06 8.67 -17.70 -28.53 -28.53For z = h: 36.67 1.02 18.06 8.67 -17.70 -28.53 -28.53

Notes: 1. (+) and (-) signs signify wind pressures acting toward & away from respective surfaces. 2. Width of Zone 2 (edge), 'a' = 14.67 ft. 3. Width of Zone 3 (corner), 'a' = 14.67 ft.

6. For all buildings with overhangs, use Fig. 6-5B for 'GCp' values per Sect. 6.5.11.4.2.

Zone 3 shall be treated as Zone 2.


4. For monoslope roofs with q <= 3 degrees, use Fig. 6-5B for 'GCp' values with 'qh'. 5. For buildings with h > 60' and q > 10 degrees, use Fig. 6-5B for 'GCpi' values with 'qh'.

7. If a parapet >= 3' in height is provided around perimeter of roof with q <= 10 degrees,

8. Per Code Section 6.1.4.2, the minimum wind load for C&C shall not be less than 10 psf.

E86

For h <= 60', width 'a' for Zone 2 is equal to 10% of least horizontal dimension or 0.4*h, whichever is smaller, but not less than either 4% of least horizontal dimension or 3'. For h > 60', width 'a' for Zone 2 is equal to 10% of least horizontal dimension, but not less than 3'.


21 of 33 04/09/2023 19:44:20

Roof Components and Cladding:

Roof Zones for Buildings with h <= 60 ft.

Roof Zones for Buildings with h > 60 ft.

(for Gable Roofs <= 45o and Monoslope Roofs <= 3o)

(for Gable Roofs <= 10o and Monoslope Roofs <= 3o)


23 of 33 04/09/2023 19:44:20

WIND LOADING ANALYSIS - Chimneys, Stacks, and Vertical TanksPer ASCE 7-98 Code for Cantilevered Structures Classified as Other Structures

IJob Name: Subject: II


Input Data: AB

V = 90 mph (Design Wind Speed from Fig. 6-1) CClass. = II (Structure Classification from Table 1-1) D

Exposure = B (Exposure Category from Sect. 6.5.6) RoundKzt = 1.00 (Topographic Factor from Sect. 6.5.7) Hexagonal

h = 80.00 ft. (Height of Stack/Tank itself) SquareHb = 50.00 ft. (Ht. of Stack/Tank Base Above Ground) Y

D = 3.00 ft. (Diameter or Width of Surface Normal to Wind) NShape? Round (Round, Hexagonal, or Square)

0.010 (Damping Ratio = 0.010-0.070) Base Shear and Moment TabulationCt = 0.0412 (Period Coefficient = 0.020-0.035) for trapezoidal pressure distribution:Kd = 0.95 (Direct. Factor, Table 6-6) Wind Load Tabulation for Stack / Tank

z Kz qz p=qz*G*Cf F=qz*G*Cf*D(ft.) (psf) (psf) (lb/ft)

Resulting Parameters and Coefficients: 50.00 0.81 15.97 12.54 37.6155.00 0.83 16.41 12.88 38.6560.00 0.85 16.82 13.21 39.6265.00 0.87 17.21 13.51 40.54

7.00 (Table 6-4) 70.00 0.89 17.58 13.80 41.41zg = 1200 (Table 6-4) 75.00 0.91 17.93 14.08 42.23

I = 1.00 (Table 6-1) (Import. Factor) 80.00 0.93 18.26 14.34 43.02h/D = 26.667 85.00 0.94 18.58 14.59 43.77

freq., f = 0.907 Hz. (f < 1) Flexible 90.00 0.96 18.89 14.83 44.49G = 1.122 (Gust Factor, Sect. 6.5.8) 95.00 0.97 19.18 15.06 45.18Cf = 0.700 (Table 6-10) (Press. Coef.) 100.00 0.99 19.47 15.28 45.85

(for Mod. Smooth Surface) 105.00 1.00 19.74 15.50 46.49110.00 1.02 20.00 15.71 47.12

Velocity Pressure (Sect. 6.5.10, Eq. 6-13): 120.00 1.04 20.51 16.10 48.30qz = 0.00256*Kz*Kzt*Kd*V^2*I 130.00 1.07 20.98 16.47 49.42

Net Design Wind Pressures (Sect. 6.5.13):p = qz*G*Cf (psf)

Net Design Wind Forces (Sect. 6.5.13, Eq. 6-20):F = qz*G*Cf*D (lb/ft)

Resulting Total Base Shear & Moment:

3.53 kips324.23 ft-kips

b = Elevation

If z < 15 then: Kz = 2.01*(15/zg)^(2/a)If z >= 15 then: Kz = 2.01*(z/zg)^(2/a)

a =

SV(total) =SM(total) =

Ground

D

h

Hb >= 0

Wind

B9


B10


B11

Exposure Categories adequately reflect the characteristics of ground surface irregularities at the structure site. Exposure Categories are as follows: Exposure "A": Large city centers with at least 50% of the structures having a height in excess of 70'. Use of this exposure category is limited to those areas for which terrain representative of Exposure "A" prevails in the upwind direction for a distance >= 0.5 miles or 10 times the height of the structure, whichever is greater. Exposure "B": Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger. Use of this exposure category is limited to those areas for which terrain representative of Exposure "B" prevails in the upwind direction for a distance >= 1,500' or 10 times the height of the structure, whichever is greater. Exposure "C": Open terrain with scattered obstructions having heights generally less than 30'. This category includes flat open country, grasslands and shorelines in hurricane prone regions. Exposure "D": Flat, unobstructed areas exposed to wind flowing over open water (excluding shorelines in hurricane prone regions) for a distance of at least 1 mile. Shorelines in Exposure D include inland waterways, the Great Lakes and coastal areas of California, Oregon, Washington and Alaska. This exposure applies only to those structures exposed to the wind coming from over the water. Exposure "D" extends inland from the shoreline a distance >= 1,500' or 10 times the height of the structure, whichever is greater.

B12

The Topographic Factor, Kzt, accounts for effect of wind speed-up over isolated hills and escarpments (Sect. 6.5.7 and Fig. 6-2). Kzt = (1=K1*K2*K3)^2 (Eq. 6-1), where: H = height of hill or escarpment relative to the upwind terrain, in feet. Lh = Distance upwind of crest to where the difference in ground elevation is half the height of hill or escarpment, in feet. K1 = factor to account for shape of topographic feature and maximum speed-up effect. K2 = factor to account for reduction in speed-up with distance upwind or downwind of crest. K3 = factor to account for reduction in speed-up with height above local terrain. x = distance (upwind or downwind) from the crest to the structure site, in feet. z = height above local ground level, in feet. The effect of wind speed-up shall not be required to be considered (Kzt = 1.0) when H/Lh < 0.2, or H < 15' for Exposures 'C' and 'D', or H < 60' for Exposures 'A' and 'B'.

B17

The Damping Ratio, b, is the percent of critical damping. It is only used in the calculation of the Gust Factor, Gf, when a structure is considered "flexible". A structure is considered "flexible" when it has a natural frequency, f < 1 hz. Otherwise the structure is considered "rigid". Suggested range of values is from 0.010 to 0.070. Note: if the structure is "flexible", the smaller the value of the damping ratio, the larger the gust effect factor, Gf, becomes.

B18

The structure Period Coefficient, Ct, has suggested range of values from 0.020 to 0.035. It is used in the equation for the assumed period of the structure: T = Ct*h^3/4. Then the natural frequency, f, is determined by: f = 1/T. It is only used in the calculation of the Gust Factor, Gf, when a structure is considered "flexible". A structure is considered "flexible" when it has a natural frequency, f < 1 hz. Otherwise the structure is considered "rigid". Note: if the period, T, or the natural frequency, f, is already known (obtained by other means), then the value of Ct may be "manipulated" to give the desired results for T and f.

B19

Wind Directionality Factor, Kd (Table 6-6) Structure Type Kd Chimneys, Tanks, and Similar Structures Square 0.90 Hexagonal 0.95 Round 0.95 Note: this factor shall only be applied when used in conjunction with load combinations specified in Sect. 2.3 and 2.4. Otherwise, use Kd = 1.0.

C26


C28


C32

Force Coefficients for Chimneys, Tanks, and Similar Structures, Cf (Table 6-10): Cf for h/D Values of: Cross-Section Type of Surface 1 7 25 Square (wind normal to face) All 1.3 1.4 2.0 Square (wind along diagonal) All 1.0 1.1 1.5 Hexagonal or Octagonal All 1.0 1.2 1.4 Round (D*SQRT(qz)>2.5)** Moderately smooth** 0.5 0.6 0.7 **Note: This program assumes only moderately smooth surfaces for round structures and assumes D*SQRT(qz)>2.5.

D38

Per Code Section 6.1.4.1, the minimum wind load to be used shall not be less than 10 psf.

B46

Total wind shear at base is calculated using a trapezoidal shaped wind pressure diagram.

B47

Total wind moment at base is calculated using a trapezoidal shaped wind pressure diagram.


24 of 33 04/09/2023 19:44:20

Determination of Gust Effect Factor, G:###

Flexible? Yes f < 1 Hz.

G = N.A.

Parameters Used in Both Item #2 and Item #3 Calculations (from Table 6-4):

0.143b^ = 0.84

0.250b(bar) = 0.45

c = 0.30

320 ft.0.333

z(min) = 30 ft.

Calculated Parameters Used in Both Rigid and/or Flexible Structure Calculations:

z(bar) = 48.00 = 0.6*h , but not < z(min) , ft.Iz(bar) = 0.282 = c*(33/z(bar))^(1/6) , Eq. 6-3

Lz(bar) = 362.57gq = 3.4 (3.4, per Sect. 6.5.8.1)gv = 3.4 (3.4, per Sect. 6.5.8.1)gr = 4.166 = (2*(LN(3600*f)))^(1/2)+0.577/(2*LN(3600*f))^(1/2) , Eq. 6-7Q = 0.895 = (1/(1+0.63*((B+h)/Lz(bar))^0.63))^(1/2) , Eq. 6-4

G = N.A. = 0.925*((1+1.7*gq*Iz(bar)*Q)/(1+1.7*gv*Iz(bar))) , Eq. 6-2

0.010 Damping RatioCt = 0.041 Period CoefficientT = 1.102 = Ct*h^(3/4) , sec. (Period)f = 0.907 = 1/T , Hz. (Natural Frequency)

V(fps) = 132.00 = V(mph)*(88/60) , ft./sec.

V(bar,zbar) = 65.23N1 = 5.043 = f*Lz(bar)/(V(bar,zbar)) , Eq. 6-10

Rn = 0.050 = 7.47*N1/(1+10.3*N1)^(5/3) , Eq. 6-95.119 = 4.6*f*h/(V(bar,zbar))

Rh = 0.1760.192 = 4.6*f*b/(V(bar,zbar))

RB = 0.8830.643 = 15.4*f*L/(V(bar,zbar))

RL = 0.680R = 0.817

Gf = 1.122 = 0.925*(1+1.7*Iz(bar)*(gq^2*Q^2+gr^2*R^2)^(1/2))/(1+1.7*gv*Iz(bar)) , Eq. 6-6Use: G = 1.122

SV(total):

1: Simplified Method for Rigid Structure

a^ =

a(bar) =

l =e(bar) =

= l*(z(bar)/33)^(e(bar)) , Eq. 6-5

2: Calculation of G for Rigid Structure

3: Calculation of Gf for Flexible Structureb =

= b(bar)*(z(bar)/33)^(a(bar))*V*(88/60) , ft./sec. , Eq. 6-12

hh =

= (1/hh)-1/(2*hh^2)*(1-e^(-2*hh)) for hh > 0, or = 1 for hh = 0 , Eq. 6-11a,b hB =

= (1/hB)-1/(2*hB^2)*(1-e^(-2*hB)) for hB > 0, or = 1 for hB = 0 , Eq. 6-11a,b hd =

= (1/hL)-1/(2*hL^2)*(1-e^(-2*hL)) for hL > 0, or = 1 for hL = 0 , Eq. 6-11a,b = ((1/b)*Rn*Rh*RB*(0.53+0.47*RL))^(1/2) , Eq. 6-8

B55

Structures which have a natural frequency, f >= 1 Hz are considered "rigid". Structures which have a natural frequency, f < 1 Hz are considered "flexible".

D57

The Gust Effect Factor, G, for rigid structures may be simply taken as 0.85 for all structure exposure conditions.

H60

Terrain Exposure Constants (Table 6-4) Exposure a zg(ft) a^ b^ a(bar) b(bar) c l(ft) e z(min) A 5.0 1500 1/5 0.64 1/3.0 0.30 0.45 180 1/2.0 60 B 7.0 1200 1/7 0.84 1/4.0 0.45 0.30 320 1/3.0 30 C 9.5 900 1/9.5 1.00 1/6.5 0.65 0.20 500 1/5.0 15 D 11.5 700 1/11.5 1.07 1/9.0 0.80 0.15 650 1/8.0 7 Note: z(min) = minimum height used to ensure that the equivalent height z(bar) is greater of 0.6*h or z(min). For structures with h<= z(min), z(bar) shall be taken as z(min).

B71

The Equivalent Height of the Structure, z(bar). z(bar) = 0.6*h but not less than z(min) from Table C6-6.

B72

The Intensity of Turbulence at height = z(bar). Iz(bar) = c*(33/z(bar))^(1/6)

B73

The Integral Length Scale of Turbulence at the equivalent height. Lz(bar) = l*(z(bar)/33)^(e (bar))

B74

Peak Factor for backround response: gq = 3.4 (per Sect. 6.5.8.1)

B75

Peak Factor for wind response: gv = 3.4 (per Sect. 6.5.8.1)

B76

Peak Factor for resonant response: gr = (2*(LN(3600*f)))^(1/2)+0.577/(2*LN(3600*f))^(1/2) Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B77

The Backround Response Factor, Q. Q = (1/(1+0.63*((B+h)/Lz(bar))^0.63))^(1/2) where: B = structure width normal to wind h = structure mean roof height

C79

The Gust Effect Factor, G, for a rigid structure as calculated from Eqn. 6-2.

B80

The Gust Effect Factor, G, for a "rigid" structure. G = 0.925*((1+1.7*gq*Iz(bar)*Q)/(1+1.7*gv*Iz(bar))) where: gq = 3.4 and gv = 3.4

D82

The Gust Effect Factor, Gf, for a flexible structure as calculated from Eqn 6-6. Note: calculations below are applicable only for "flexible" structures which have a natural frequency, f < 1 hz.

B87

The Basic Wind Speed, V, converted from units of mph to ft/sec. V(fps) = V(mph)*(88/60)

B88

The Mean Hourly Wind Speed, V(bar,zbar). V(bar,zbar) = b(bar)*(z(bar)/33)^(a(bar))*V*(88/60)

B89

N1 = f*Lz(bar)/(V(bar,zbar)) Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B90

Rn = 7.47*N1/(1+10.3*N1)^(5/3)

B91

hh = 4.6*f*h/(V(bar,zbar)) Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B92

Rh = (1/hh)-1/(2*hh^2)*(1-e^(-2*hh)) for hh > 0 or: Rh = 1 for hh = 0

B93

hb =4.6*f*b/(V(bar,zbar)) where: b = building width normal to wind Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B94

RB = (1/hB)-1/(2*hB^2)*(1-e^(-2*hB)) for hB > 0 or: RB = 1 for hB = 0

B95

hd = 15.4*f*d/(V(bar,zbar)) where: d = depth of building parallel to wind Note: the symbol, f, was subsituted for the original symbol, n1, in the equation above.

B96

RL = (1/hL)-1/(2*hL^2)*(1-e^(-2*hL)) for hL > 0 or: RL = 1 for hL = 0

B97

The Resonant Response Factor, R. R = ((1/b)*Rn*Rh*Rb*(0.53+0.47*Rd))^1/2

B98

The Gust Effect Factor, Gf, for a "flexible" building. Gf = 0.925*(1+1.7*Iz(bar)*(gq^2*Q^2+gr^2*R^2))^(1/2)/(1+1.7*gv*Iz(bar))

B99

For a rigid structure, the smaller of the value of either 0.85 or the value as calculated in item #2 is used for the gust effect factor, G.


25 of 33 04/09/2023 19:44:20

FIGURE 6-1: Basic Wind Speed

FIGURE 6-1a: Western Gulf of Mexico Hurricane Coastline

FIGURE 6-1b: Eastern Gulf & Southeastern U.S. Hurricane Coastline

FIGURE 6-1c: Mid and Northern Atlantic Hurricane Coastline

37988564 asce 7 98 code wind loading analysis

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