Load Generator

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Automate wind speed, wind design and snow calculations.

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Functions

The following functions assist in the determination of loads due to wind and snow.

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loads.getLoads

Using the below variables, users can get the wind speed, snow loads and wind pressures from ASCE, AS1170, NBCC or Eurocode Design Standards.

Sample input for loads.getLoads

{

"function": "loads.getLoads",

"arguments": {

"site_data": {},

"building_data": {}

}

}

Try loads.getLoads

Relevant components

• The site_data object
• The building_data object

The response will return design wind speed, elevations, topography, wind and snow pressures and confirm the address of the site location under the key wind_speed. In addition to this, if the terrain data is requested (user provides wind_direction and exposure keys) it will also return topography data:

Sample response for loads.getLoads

{

"site_data": {

"country": "United Kingdom",

"lat": 51.501364,

"lng": -0.14189,

"elevation": 6.36,

"formatted_address": "Westminster, London SW1A 1AA, UK"

},

"wind_data": {

"uk_ireland_contour": 21.621648873984707,

"distance_from_shore": {

"0": {

"distance": 233.92573712464545,

"lat": 53.60510578995467,

"lng": -0.1418899999999966

},

"30": {

"distance": 174.5852678317777,

"lat": 52.98168910830151,

"lng": 0.7127760997660391

}

// etc

},

"wind_speed": 21.8

},

"snow_data": {

"snow_region": "zone3",

"snow_load": 0.5

},

"topography": {

"code": "en1991",

"topo_factor": 1,

"comments": "",

"location_of_peak": 1740,

"elevation_of_peak": 26.6097240447998,

"location_of_foot": -1580,

"elevation_of_foot": 0,

"elevation_of_midheight": 13.3048620223999,

"slope": 0.008014977121927652,

"H": 26.6097240447998,

"x": -1740,

"Lu": 3320,

"Ld": 240,

"terrain_type": "Flat",

"elevation_image_base64": "**Base 64 Data**"

},

"snow_pressure": null,

"wind_pressure": {

"pressure_type": "building",

"pressure_unit": "Pa",

"elevation_or_location_unit": "m",

"pressures": [

{

"dirn": "along_L",

"surface": "windward_wall",

"elevation": [3, 6, 9],

"pos_Cpi": [204.49, 204.49, 204.49],

"neg_Cpi": [425.75, 425.75, 425.75]

},

{

"dirn": "along_L",

"surface": "leeward_wall",

"elevation": 21,

"pos_Cpi": -325.11,

"neg_Cpi": -103.85

},

{

"dirn": "along_L",

"surface": "sidewall",

"location": [2, 10, 12.4],

"pos_Cpi": [-619.531865399467, -442.5227609996193, -309.7659326997335],

"neg_Cpi": [-398.27048489965733, -221.26138049980966, -88.50455219992386]

},

{

"surface": "roof",

"zone": "F",

"pos_Cpi": 194.71,

"neg_Cpi": -592.98

},

{

"surface": "roof",

"zone": "G",

"pos_Cpi": 194.71,

"neg_Cpi": -495.63

},

// etc

],

"forces": null

}

}

Here is a sample of the elevation image that is returned when elevation_img: true :

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wind.getPressures

For generating pressure loads with respect to site and building data.

ASCE 7 Freestanding Wall/Solid Signs

Sample input for wind.getPressures

{

"function": "wind.getPressures",

"arguments": {

"design_code": "asce7-16", //asce7-10 or asce7-16

"structure": "freestandingwall", //building, freestandingwall, trusstower

"freestandingwall_dimensions": {

"ground_to_top": 20, //ground to top of wall

"wall_width": 50,

"wall_height": 10,

"ratio_of_solid_area_to_gross": 0.9, // between 0 to 1.0

"length_of_return_corner": 0

},

"wind_parameters": {

"structure_type": "freestandingwall-asce7-16" //freestandingwall or freestandingwall-asce7-16

},

"snow_parameters": false // not available for freestandingwall and truss towers

}

}

ASCE 7 Building

Sample input for wind.getPressures

{

"function": "wind.getPressures",

"arguments": {

"design_code": "asce7-16", //asce7-10 or asce7-16

"structure": "building", //building, freestandingwall, trusstower

"roof_profile": "hip", //gable, hip, monoslope, pitched, troughed, open-monoslope

"building_dimensions": {

"length": 12.4,

"width": 10,

"mean_roof_height": 21,

"roof_angle": 12

},

// "wind_parameters" can be an object or false if not considered

"wind_parameters": {

"structure_type": "mwfrs", // mwfrs or cladding

"enclosure": "enclosed", //enclosed, partially_enclosed, open, partially-open

"wind_blockage": "obstructed", // clear or obstructed

// FOR CLADDING

"wall_cladding_area": 1, //wall-cladding-area

"roof_cladding_area": 1, // roof-cladding-area

"cladding_type": "permeable", // permeable or impermeable

"structure_level": [

{ "floor_level": "2", "floor_elevation": 3 },

{ "floor_level": "3", "floor_elevation": 6 },

{ "floor_level": "roof", "floor_elevation": 9 }

]

},

// "snow_parameters" can be an object or false if not considered

"snow_parameters": {

"terrain_category": "B", // B, C, D, above-treeline, alaska-no-trees

"exposure_condition_roof": "sheltered", // fully-exposed, partially-exposed, sheltered

"thermal_condition": "structure-above-freezing", // unheated-open, structure-below-freezing, greenhouse, all-structures, structure-above-freezing

"sloped_roof_surface_condition": "slippery", // slippery, all-other

"unbalanced_snow_load": true, // true or false if unbalanced snow load is considered

"snow_load_case": [

{

"snow_case_type": "symmetric_gable", // symmetric_gable , asymmetric_gable, lower_roof

"W": 20 //horizontal dist from eav to ridge of symmetric gable

},

{

"snow_case_type": "asymmetric_gable",

"Wu": 22, // horizontal dist from eav to ridge on upwind side of gable roof

"Wd": 18, // horizontal dist from eav to ridge on downwind side of gable roof

"theta_u": 13, // roof angle on upwind side of gable roof

"theta_d": 16 // roof angle on downwind side of gable roof

},

{

"snow_case_type": "lower_roof",

"lu": 8, // length of upper roof (upwind)

"hr": 3, // height difference between upper and lower roof

"ld": 6 // length of lower roof (downwind)

}

]

}

}

}

ASCE 7 Truss Tower

Sample input for wind.getPressures

{

"function": "wind.getPressures",

"arguments": {

"design_code": "asce7-16",

"structure": "trusstower", //building, freestandingwall, trusstower

"trusstower_dimensions": {

"ground_to_top": "80", //ground to top of truss tower

"ground_to_centroid": "33",

"ratio_of_solid_area_to_gross": "0.23", // between 0 to 1.0

"tower_cross_section": "square", //square or triangle

"member_section": "round", //round or flat

"tower_length": "20", //dimension of one side for square or triangle

"truss_type": "cross", //warren cross pratt howe

"base_column_height": "10", //column/pedestal height

"top_base_ratio": "0.6" //ratio of top dimension to bottom dimension

},

"wind_parameters": {

"structure_type": "trusstower-asce7-16", //trusstower or trusstower-asce7-16

"structure_level": [

{

"node_level": "2",

"node_elevation": 10

},

{

"node_level": "3",

"node_elevation": 20

},

{

"node_level": "roof",

"node_elevation": 30

}

]

},

"snow_parameters": false

}

}

EN 1991

Sample input for wind.getPressures

const bld_args = {

design_code: 'en1991',

structure: 'building',

roof_profile: 'gable', //gable, hip, monoslope, pitched, troughed, open-monoslope

building_dimensions: {

length: 12.4,

width: 10,

ground_to_top: 21,

roof_angle: 12,

},

//"wind_parameters" can be an object or false if not considered

wind_parameters: {

structure_type: 'building', // building or free_roof

// "wind_blockage": "obstructed", // clear or obstructed,

flat_roof_type: 'not-applicable', // not-applicable, sharp-eaves, with-parapet, curved-eaves, mansard-eaves

structure_level: [

{ floor_level: '2', floor_elevation: 3 },

{ floor_level: '3', floor_elevation: 6 },

{ floor_level: 'roof', floor_elevation: 9 },

],

wall_area_en1991: 10, //optional - default value is 10. Ranging from 1 to 10 sqm if wall component/cladding is analyzed

roof_area_en1991: 10, //optional - default value is 10. Ranging from 1 to 10 sqm if roof component/cladding is analyzed

},

// "snow_parameters" can be an object or false if not considered

snow_parameters: false,

};

AS/NZS 1170

Sample input for wind.getPressures

const bld_args = {

design_code: 'as1170',

structure: 'building',

roof_profile: 'gable', //gable, hip, monoslope, pitched, troughed, open-monoslope

building_dimensions: {

length: 12.4,

width: 10,

height: 21,

roof_angle: 12,

mean_roof_height: 22,

},

// "wind_parameters" can be an object or false if not considered

wind_parameters: {

structure_type: 'building', // building, free-roof, cladding

wind_blockage: 'blocked', // empty or blocked

elevated_building: false, //true or false

wind_blockage: '',

wall_condition: '5', // 1 to 9

action_combination_case: '1', // 1 to 8

wall_type: 'impermeable', // permeable or impermeable

ratio_of_opening_to_total_area: '0',

structure_level: [

{ floor_level: '2', floor_elevation: 3 },

{ floor_level: '3', floor_elevation: 6 },

{ floor_level: 'roof', floor_elevation: 9 },

],

// FOR CLADDING

// "wall_cladding_area": 1, //wall-cladding-area

// "roof_cladding_area": 1, // roof-cladding-area

// "cladding_type": "permeable", // permeable or impermeable

},

// "snow_parameters" can be an object or false if not considered

snow_parameters: {

exposure_category_as1170: 'windswept', // sub-alpine, sheltered, semi-sheltered, windswept

unbalanced_snow_load: true, // true/false if unbalanced snow load is considered

snow_load_case: [

{

snow_case_type: 'unbalanced_duopitched',

theta1: 16,

theta2: 18,

},

{

snow_case_type: 'unbalanced_monopitched',

theta: 16,

},

{

snow_case_type: 'drifting_sheltered',

l1: 20,

l2: 20,

hd: 3,

theta1: 17,

theta2: 17,

},

{

snow_case_type: 'drifting_lower_upper',

l1: 20,

l2: 20,

hd: 3,

hr: 5,

theta1: 17,

theta2: 17,

},

{

snow_case_type: 'drifting_projection_obstruction',

h: 3,

theta: 17,

},

{

snow_case_type: 'obstructed_sloping_roof_subalpine_parapet',

hp: 2,

theta: 17,

},

{

snow_case_type: 'obstructed_sloping_roof_subalpine_abutting',

theta: 16,

},

{

snow_case_type: 'drifting_lower_roof_subalpine',

theta1: 20,

theta2: 13,

hd: 2.5,

},

],

},

};

const functions = [

{

function: 'wind.getWindSpeed',

arguments: wind_speed_args, //from above wind.getindSpeed

},

{

function: 'wind.getPressures',

arguments: bld_args,

},

];

NBCC 2015

Sample input for wind.getPressures

const bld_args = {

design_code: 'nbcc2015',

structure: 'building',

roof_profile: 'gable', //gable, hip, monoslope, pitched, troughed, open-monoslope

building_dimensions: {

length: 12.4,

width: 10,

reference_height: 21,

roof_angle: 12,

},

// "wind_parameters" can be an object or false if not considered

wind_parameters: {

structure_type: 'cladding', // mwfrs or cladding

enclosure: 'enclosed', // enclosed, partially_enclosed, open, partially-open

wind_blockage: 'obstructed', // clear or obstructed,

cladding_pressure_type: 'external', // external, external_internal

wall_cladding_area: 10, // wall cladding area

roof_cladding_area: 12, // roof cladding area

structure_level: [

{ floor_level: '2', floor_elevation: 3 },

{ floor_level: '3', floor_elevation: 6 },

{ floor_level: 'roof', floor_elevation: 9 },

],

},

// "snow_parameters" can be an object or false if not considered

snow_parameters: {

sloped_roof_surface_condition: 'slippery', // slippery, all-other//

unbalanced_snow_load: true, //true false

snow_load_case: [

{

snow_case_type: 'multilevel_roof_case1', // "multilevel_roof_case1" "multilevel_roof_case2" "multilevel_roof_case3"

ls: 20,

ws: 13,

h: 13,

hp: 13,

alpha: 13,

sliding: true, // true or false

a: 13,

},

{

snow_case_type: 'areas_adjacent_to_roof_projections',

ls: 20,

ws: 13,

h: 13,

lh10: 13,

},

{

snow_case_type: 'gable_roof',

ls: 20,

ws: 13,

alpha: 13,

},

],

},

};

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Objects

The following objects are required arguments for the above functions.

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site_data

Get wind speed from site location, based on ASCE 7-10, ASCE 7-16, AS/NZS 1170, NBCC and EN 1991.

Common properties for all design codes

Key	Type	Description
design_code	string	Which design code is this based on: as1170, asce7-10, asce7-16, en1991, nbcc2015.
project_address	string	The site location. This will use Google Maps to search the address and select the first option.
wind_direction	string	Wind direction (going to). N, NE, E, SE, S, SW, W, NW.
lat	float	Latitude of site location (used instead of project_address). E.g. 41.878100 for Chicago
lng	float	Longitude of site location (used instead of project_address). E.g. -87.629800 for Chicago

Design code specific properties

Key	Type	Design Code	Description/Options
risk_category	string	ASCE 7	I, II, III, IV
exposure	string	ASCE 7	Required for topography result B, C, D
ari	integer	AS/NZS 1170	Annual Recurrence Interval (in years) 1, 5, 10, 20, 25, 50, 100, 200, 250, 500, 1000, 2000, 2500, 5000, 10000
sls_and_uls	boolean	AS/NZS 1170	true or false
country	string	AS/NZS 1170	australia or new_zealand Required for SLS and ULS wind speeds
design_working_life	string	AS/NZS 1170	construction_equipment, 10_years, 25_years, 50_years, 100_years, less_than_6_months (NZ only) Required for SLS and ULS wind speeds
importance_level	string	AS/NZS 1170	Number between 1, 5 specifying importance level Required for SLS and ULS wind speeds

Design code specific topography properties

Key	Type	Design Code	Description/Options
terrain_category	string	AS/NZS 1170	CAT2, CAT3, CAT4
snow_region	string	AS/NZS 1170	alpine, sub-alpine
snow_terrain_class	integer	AS/NZS 1170	1, 2, 3
ari	string	NBCC 2015	Annual Recurrence Interval: 10_years, 50_years
importance_level	string	NBCC 2015	low, normal, high, post_disaster
limit_state	string	NBCC 2015	SLS, ULS
snow_area_classification	string	NBCC 2015	rural, exposed-north-treeline
country	string	EN 1991	Germany, United Kingdom, France... Required for additional parameters (season_month, wind_direction, terrain_category
season_month	string	EN 1991	For Belgium, France, UK, and Ireland 1 month: January, February, ... 2 months (UK and Ireland only): January-February, March-April, ... 4 months (UK and Ireland only): November-February, December-March, ... 6 months (UK and Ireland only): October-March, April-September, ...
wind_direction	string or integer	EN 1991	The angle of which the wind is going to, referenced from N in clockwise direction. Use Any for worst case For Belgium, Poland, United Kingdom, Ireland, and France: (in degrees). Increments of 30° ranging from 0 - 360 For other countries: N, NE, E, SE, S, SW, W, NW
terrain_category	string	EN 1991	For UK and Ireland: 0 for Sea I or II for Country III or IV for Town For France: 0 II IIIa IIIb IV For Netherlands: 0 II III Other countries: I II III IV
distance_inside_town	float	EN 1991	Required for UK and Ireland. Default value is 20
distance_from_shore	float	EN 1991	Required for UK and Ireland. Can be obtained from server if wind direction is not equal to Any. Default value is 100
displacement_height	float	EN 1991	Required for UK and Ireland. Default value is 0

ASCE 7-16

Sample site_data input

{

"design_code": "asce7-16",

"project_address": "Wacker Avenue, Chicago",

"country": "United States",

"risk_category": "III",

// lat: 41.878100, or lat: 41°52"41.2"N

// lng: -87.629800, or lng: 87°37"47.3"W

"topography": {

"terrain_data": true,

"wind_direction": "N",

"exposure": "B",

"topo_image": true,

}

}

AS/NZS 1170.2

Sample site_data input

{

"design_code": "as1170",

"project_address": "Cabramurra, NSW",

"ari": "200",

"sls_and_uls": true, //requires below information

"country": "australia",

"design_working_life": "25_years",

"importance_level": "3",

"topography": {

"terrain_data": true,

"wind_direction": "E",

"terrain_category": "CAT2",

"topo_image": true,

"country": "United States",

"snow_region": "alpine",

"snow_terrain_class": "1"

}

}

NBCC 2015

Sample site_data input

{

"design_code": "nbcc2015",

"project_address": "Toronto",

"ari": "10_years", //50_years

"importance_level": "low", //normal, high, post_disaster

"limit_state": "SLS", // ULS

"topography": {

"terrain_data": true,

"wind_direction": "N", //NE etc...

"terrain_category": "A", //B

"topo_image": true,

"country": "Canada",

"snow_area_classification": "rural"

}

}

EN 1991

Sample site_data input

{

"design_code": "en1991",

"project_address": "Buckingham Palace",

"topography": {

"terrain_data": true,

"season_month": "January-February",

"wind_direction": "30", //degrees

"topo_image": true,

"country": "United Kingdom",

"season_month": "January-February",

"terrain_category": "I",

"distance_inside_town": 20,

"distance_from_shore": 100,

"displacement_height": 0

}

}

Try loads.getLoads

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building_data

Generate wind pressures or snow loads based on building parameters. These parameters have minor differences between design codes. If you need any assistance, please email us at [email protected].

Options for Structure

structure	Remarks
building	Default value
freestanding_wall	ASCE 7 only
truss_tower	ASCE 7 only

Options for ASCE 7, NBCC 2015

roof_profile	enclosure	wind_blockage
gable	enclosed, partially-enclosed, partially-open
monoslope	enclosed, partially-enclosed, partially-open
hip	enclosed, partially-enclosed, partially-open
pitched	open	For ASCE 7/NBCC 2015: clear, obstructed For AS/NZS 1170: empty, blocked
troughed	open	string
open-monoslope	open	string

structure_type	Description
mwfrs	Main Wind Force Resisting System
cladding	Components and Cladding

Options for AS/NZS 1170 and EN 1991

structure_type	roof_profile
building	gable, monoslope, hip
free_roof	For EN 1991: pitched, open-monoslope For AS/NZS 1170: pitched, open-monoslope, troughed
For AS/NZS 1170: cladding	gable, monoslope, hip, pitched, open-monoslope, troughed

For more info on parameters used for wind or snow load calculation, please refer to our documentation and/or the load generator UI.