Calculate Wall Bracing - Part 3 - Calculate the Area of Elevation and Calculate the Racking Force.

Summary

In this third installment of the 'Buildsum' series, the focus is on calculating wall bracing, specifically determining the end elevation and the racking force exerted by wind loads on a building. The video explains how to calculate areas for both wind directions, considering roof pitch and building dimensions, and then uses these to determine the racking forces for each wind direction. With a clear demonstration of the process, the video prepares viewers for the next step: incorporating sufficient bracing to resist these forces.

Takeaways

• 🏗️ The video is part of a series on calculating wall bracing, focusing on determining end elevation and calculating racking force due to wind loads.
• 📐 The process starts by examining wind direction one, which impacts the long side of the building, and only half of the wall elevation needs to be calculated.
• ⚠️ Eaves are not considered unless they extend more than a meter beyond the wall, simplifying the calculation.
• 📏 The building's dimensions, such as length, width, and wall height, are essential for calculating the area of the wall and roof affected by wind.
• 📐 The area of the wall is calculated by multiplying the building's length by half the wall height, while the roof area requires additional geometric considerations.
• 📐 For the roof, the area is determined by creating a rectangle from the triangle formed by cutting off the eave and using trigonometric functions related to the roof pitch.
• 🔢 The total area for wind direction one is calculated to be 43.553 square meters, combining both wall and roof areas.
• 🌪️ The racking force is calculated by multiplying the wind pressure by the total area of the elevation, resulting in forces for different wind directions.
• 🌪️ Wind direction one has a wind pressure of 1.1 kiloPascals, leading to a racking force of 47.908 kiloPascals acting on the building.
• 🌪️ Wind direction two, with a higher wind pressure of 1.2 kiloPascals, results in a racking force of 20.254 kiloPascals on the building.
• 🛠️ The next step, as hinted in the video, is to ensure the building has adequate bracing to resist the calculated racking forces.

Q & A

What is the main topic of the video?

The main topic of the video is calculating wall bracing and determining the racking force due to wind loads on a building.

What is the significance of wind direction in the context of this video?

Wind direction is significant because it affects how the wind loads are applied to the building, and the video specifically discusses wind direction one, which is the wind blowing onto the long side of the building.

What is the process for determining the area to be calculated for wind loads?

The process involves calculating only half of the wall elevation and not considering the eaves unless they extend more than a meter past the outside of the wall.

What is the roof pitch mentioned in the video?

The roof pitch mentioned in the video is 30 degrees.

How is the half span of the building calculated in the video?

The half span is calculated by using the building's length and the roof pitch, which gives a half span of 3.635 meters.

What is the formula used to calculate the area of the wall in the video?

The formula used is the length of the building multiplied by half the wall height.

How does the presenter simplify the calculation of the roof area?

The presenter simplifies the calculation by creating a rectangle from the triangular roof area by cutting it off and sticking it next to the wall area.

What is the calculated area of the roof for wind direction one?

The calculated area of the roof for wind direction one is 23.519 square meters.

How is the total elevation area for wind direction one calculated?

The total elevation area for wind direction one is calculated by adding the area of the wall and the area of the roof, resulting in 43.553 square meters.

What is the wind pressure for wind direction one mentioned in the video?

The wind pressure for wind direction one is 1.1 kiloPascals.

How is the racking force due to wind direction one calculated?

The racking force is calculated by multiplying the wind pressure by the total elevation area, resulting in a force of 47.908 kiloPascals.

Outlines

00:00

🏗️ Calculating Wall Bracing and Racking Force

This video segment focuses on the third part of a series on calculating wall bracing. The host explains how to determine the end elevation and calculate the racking force due to wind loads on a building. They discuss wind direction one, which impacts the long side of the building, and emphasize that only half of the wall elevation needs to be calculated. The video provides a diagram and notes on the calculation process, including the exclusion of eaves unless they extend more than a meter past the wall. The roof pitch of 30 degrees and the building dimensions are used to calculate the wall and roof areas, which are then combined to determine the total area for wind direction one. The process is repeated for wind direction two, and the areas are used to calculate the racking force for both wind directions, with wind direction one having a pressure of 1.1 kiloPascals and wind direction two having a pressure of 1.2 kiloPascals.

05:04

📢 Engaging with Buildsum's Content

In this brief segment, the host encourages viewers to engage with their content by subscribing to their YouTube channel or following them on Facebook. This call to action ensures that viewers stay updated with more informative videos on similar topics, highlighting the importance of continuous learning and engagement in the field of construction and engineering.

Keywords

💡Wall Bracing

Wall bracing refers to the structural elements used to provide lateral support to a building, preventing it from racking or collapsing under lateral loads such as wind. In the video's context, the process of calculating wall bracing is the main focus, with the presenter explaining how to determine the necessary bracing to resist the racking forces caused by wind.

💡End Elevation

End elevation in architecture and construction is the vertical dimension of a building when viewed from one end. The script discusses determining the end elevation to calculate the area that will be affected by wind loads, which is essential for understanding the forces that need to be resisted by the wall bracing.

💡Racking Force

Racking force is the lateral force that can cause a structure to deform or collapse in a diagonal pattern, resembling the racking of a stack of playing cards. The video explains how to calculate this force for different wind directions, which is critical for designing adequate wall bracing.

💡Wind Loads

Wind loads are the forces exerted on structures by wind, which can cause lateral pressure and movement. The script details how to calculate the racking force based on wind direction and pressure, which is a key step in determining the required wall bracing.

💡Eaves

Eaves are the overhanging edges of a roof, extending beyond the walls of a building. The video mentions that eaves do not need to be considered in the calculation unless they extend more than a meter past the wall, indicating that they can have an impact on wind loads but are simplified in this scenario for calculation purposes.

💡Roof Pitch

Roof pitch, also known as the angle of the roof, is a critical measurement in construction that affects how wind interacts with the building. The script uses a 30-degree roof pitch to calculate the area of the roof and its contribution to the overall wind load.

💡Half Span

Half span refers to half the length of the building, used in the script to simplify the calculation of the wall and roof areas affected by wind. It is a method to reduce the complexity of the calculations without significantly affecting the accuracy for the purpose of determining wall bracing requirements.

💡Area Calculation

Area calculation is the process of determining the surface area of a structure or part of it. In the script, the presenter calculates the area of the wall and roof separately for different wind directions to find out the total area subjected to wind loads, which is necessary for calculating the racking force.

💡KiloPascals

KiloPascals (kPa) is a unit of pressure used to measure the force per unit area. The script uses this unit to express the wind pressure exerted on the building's elevation, which is then multiplied by the area to find the total racking force.

💡Wind Direction

Wind direction refers to the direction from which the wind is blowing relative to the building. The script discusses calculating the racking force for two wind directions, emphasizing the importance of considering different wind directions in structural design.

💡Building Length and Width

Building length and width are the dimensions of the building in its longest and shortest orientations, respectively. These measurements are fundamental in the script for calculating the areas of the wall and roof, which are then used to determine the racking force for each wind direction.

Highlights

Introduction to part 3 of the series on calculating wall bracing.

Focus on determining the end elevation and calculating racking force from wind loads.

Explanation of wind direction one affecting the long side of the building.

Diagrammatic representation of calculating only halfway up the wall elevation.

Clarification on not needing to calculate eaves if they don't extend more than a meter past the wall.

Calculation of the wall area using the building's length and half the wall height.

Method to calculate the roof area by transforming the triangle into a rectangle.

Determination of the roof pitch's impact on the calculation using a 30-degree angle.

Combining the wall and roof areas to find the total area for wind direction one.

Process for calculating the wall and roof areas for wind direction two.

Inclusion of the building's width and half the wall height in the calculation for wind direction two.

Use of previous calculations to determine the roof height for wind direction two.

Total area calculation for wind direction two combining roof and wall areas.

Calculation of racking force for wind direction one using wind pressure and elevation area.

Determination of racking force for wind direction two with its specific wind pressure.

Summary of the forces acting on the building's elevation for both wind directions.

Teaser for the next video focusing on incorporating bracing to resist the calculated forces.

Call to action for viewers to subscribe and follow for more informative videos.

Transcripts

G'day and Welcome back to Buildsum and this is part 3 of the series on calculating wall bracing and in this

video we're going to look at determining the end elevation and then calculate the

racking force that our wind loads are going to put in our building okay so we

going to look at wind direction one first which is blowing onto the long side of our

building okay so this is the elevation of our building now the table at the top

of the table there's a little diagram and it points out that you don't have to

look at the whole wall elevation you only have to calculate from halfway up

the wall okay and there's also a little note at the bottom of the page there

somewhere that says that you don't have to worry about the eaves unless they

stick of more than a meter past the outside of your wall you don't have to

calculate the eaves as well so that yellow area there is basically what

we're going to calculate in this little step so a bit of information

so the roof ptch of 30 degrees we know the building length we know the

widths it gives us a half span of 3.635m which you'll see

why in the moment and our wall height in this case was 2.7 so to work

out the elevation of the wall area this half of the wall we're just going to go

the length of the building times by half the wall height which gives us an area

of 20.034 to work out the roof what I do is I instead of trying to work

these out separately I'm going to cut this triangle off and stick

it on over here and make this one rectangle okay so this length here is

the length of the roof - the half span of the building okay so length of the

roof - a half span gives us 11.205 the height of the roof okay because our

pitch is 30 degrees it's TAN 30 times the half span they

gives us the rise of the roof so that gives us 2.099 and if it times those

threw together 11.285 by 2.099it gives us an area of 23.519

for the roof so then we add the roof and the wall together

that gives us a total area of this elevation of 43.553

metres squared okay so we'll stick that in a little memory bank

somewhere we know that area we can then do wind direction too so the short end

of the building similar process we only have to work out half the wall and the

roof don't have to worry about the eaves so same information so to work out the

wall length or width of the building times half the wall height gave us

9.815 to work out the roof I've done the same as what I did

before cut this bit off stick it over here

make it a rectangle so the length of the building minus the half span gives us

the same number 3.635 we already know the height of the

roof from our previous calculation so 2.099 so times them

together we get a total area of our roof of 7.063 square

meters so the roof plus the walls gave us a total area factor wind direction

two of 16.578 square meters so now we know the areas

of our elevations we can calculate the racking force so remembering from the

the previous video that we had a wind direction one had a wind pressure of

1.1 kiloPascals our area of the elevation is 43.553

we times those together and we get a total racking force acting on wind

direction one of 47.908 so that's basically

kiloPascals acting on that area okay and then we do the same for wind direction -

wind direction 2 had a pressure of 1.2 kiloPascals times that by our elevation

there's the area of our elevation 16.878

okay gives us a total racking force on wind direction 2

of 20.254 so now we know what the force is that's

acting on our elevation and the next video we can start to look at getting

enough bracing into our building to actually resist that force G'day I'm

back just let you know that if you like this video you can subscribe to my

youtube channel or you can follow me on Facebook so you

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