Calculate Wall Bracing - Part 4 - Design Bracing Systems - Nominal Bracing - Wind Direction 1
Summary
TLDRIn this fourth installment of the 'Buildsum' series, the focus shifts to designing bracing systems for walls. The video explains the concept of 'nominal bracing,' which relies on internal lining materials like Gyprock. It outlines rules for using nominal bracing, such as its capacity to resist only 50% of the total racking force and exclusion of panels smaller than 450mm. Using the example of a house, the video demonstrates how to calculate the resistance provided by nominal bracing for both single and double-sided walls, ultimately determining the total resistance needed in Wind Direction 1. The video promises to address Wind Direction 2 in the next episode.
Takeaways
- 🏗️ The video discusses the design of bracing systems for walls, focusing on 'nominal bracing' as the initial topic.
- 📝 Nominal bracing is made up of internal lining materials such as Gyprock or villaboard, which play a crucial role in wall stability.
- ⚠️ There are limitations to using nominal bracing; it can only resist up to 50% of the total racking force in any direction.
- 📏 A panel size less than 450mm cannot be considered for nominal bracing calculations, emphasizing the importance of panel dimensions.
- 📚 The Timber Framing Code provides specific capacities for nominal wall bracing: 0.45 kN/m for single-sided walls and 0.75 kN/m for double-sided walls.
- 📐 The process involves calculating the total length of walls that contribute to bracing and multiplying by the bracing capacity to determine resistance.
- 🏡 In the example house, the total bracing capacity for single-sided walls is calculated by adding the lengths of the walls and multiplying by 0.45 kN/m.
- 🔢 For double-sided walls, the calculation is similar but uses the 0.75 kN/m capacity, resulting in a combined resistance from nominal bracing for Wind Direction 1.
- 📉 After calculating the resistance provided by nominal bracing, the video concludes that additional resistance is required beyond what nominal bracing can provide.
- 🌪 The video script also mentions that the next part of the series will address Wind Direction 2, indicating a continuation of the topic.
- 📺 The presenter encourages viewers to subscribe or follow on social media for more informative videos on similar topics.
Q & A
What is the main topic of this video?
-The main topic of this video is the design and calculation of wall bracing systems, specifically focusing on nominal bracing.
What is the purpose of calculating the racking force on a wall?
-The purpose of calculating the racking force on a wall is to determine the force that will act on the wall due to wind pressure, which is essential for designing the bracing to resist that force.
What is the wind direction that resulted in the highest racking force in the example provided?
-Wind Direction 1 resulted in the highest racking force of 47.908 kN in the example provided.
What is the maximum percentage of the total racking force that nominal bracing can resist?
-Nominal bracing can resist up to 50 percent of the total racking force in any direction.
Why can't a panel size less than 450mm be considered in the nominal bracing calculations?
-A panel size less than 450mm cannot be considered in the nominal bracing calculations because it is too small to contribute effectively to the overall bracing capacity.
What are the bracing capacities per meter for single-sided and double-sided walls according to the Timber Framing Code?
-According to the Timber Framing Code, the bracing capacity for single-sided walls is 0.45 kN per meter, and for double-sided walls, it is 0.75 kN per meter.
How is the total bracing capacity of nominal bracing calculated for single-sided walls in the example house?
-The total bracing capacity for single-sided walls is calculated by adding the lengths of the walls (16.2m) and multiplying by the bracing capacity per meter (0.45 kN/m), resulting in 7.424 kN.
What is the total resistance from nominal bracing in Wind Direction 1 for the example house?
-The total resistance from nominal bracing in Wind Direction 1 for the example house is 21.150 kN.
What is the remaining racking force that needs to be resisted after accounting for the nominal bracing in Wind Direction 1?
-After accounting for the nominal bracing, the remaining racking force that needs to be resisted in Wind Direction 1 is 26.758 kN.
What is the next step after calculating the nominal bracing for Wind Direction 1?
-The next step, as mentioned in the video, is to calculate the bracing for Wind Direction 2.
Outlines
🏗️ Designing Wall Bracing Systems
This paragraph introduces the process of designing wall bracing systems, focusing on 'Nominal bracing.' The speaker explains that the internal lining of a wall, such as Gyprock or Villaboard, constitutes the nominal bracing. It is highlighted that nominal bracing can only resist up to 50% of the total racking force in any direction, and panels smaller than 450mm are not considered in calculations. The capacity of nominal wall bracing is given as 0.45 kN per meter for single-sided walls and 0.75 kN per meter for double-sided walls. The example of a house is used to calculate the resistance provided by the nominal bracing in Wind Direction 1, with the total length of walls and their respective capacities being factored into the calculation.
🔢 Calculating Required Bracing Force
In this paragraph, the speaker continues the discussion on wall bracing by calculating the remaining force that needs to be resisted after accounting for the nominal bracing's contribution. The calculation shows that after subtracting the resistance provided by the nominal bracing (21.150 kN) from the total racking force in Wind Direction 1 (47.908 kN), there is still a requirement for an additional 26.758 kN of resistance. The speaker reassures that the 50% rule does not apply in this case since the required force is less than half of the total racking force. The paragraph concludes with a teaser for the next video, which will address Wind Direction 2, and an invitation for viewers to subscribe or follow for more content.
Mindmap
Keywords
💡Wall Bracing
💡Racking Force
💡Nominal Bracing
💡Gyprock
💡Villaboard
💡Timber Framing Code
💡Bracing Capacity
💡Wind Direction
💡Internal Lining
💡50% Rule
Highlights
Introduction to designing bracing systems for walls in part 4 of the series on calculating wall bracing.
Explanation of 'Nominal bracing' and its significance in wall design.
Recalling the calculated pressure applied to the wall from previous discussions.
Detailing the racking force calculations for Wind Direction 1 and Wind Direction 2.
Limitation that nominal bracing can only resist 50% of the total racking force in any direction.
Rule about not considering panels less than 450mm for nominal bracing calculations.
Distribution of nominal bracing should be even throughout the building.
Capacity of nominal wall bracing for single-sided and double-sided walls as per the Timber Framing Code.
Method to calculate the length of walls for bracing capacity assessment.
Example calculation for single-sided walls using the bracing capacity per meter.
Calculation of total bracing capacity for double-sided walls and the process involved.
Summation of resistance from nominal bracing for Wind Direction 1.
Analysis of the remaining resistance required after accounting for nominal bracing.
Confirmation that the calculated nominal bracing does not exceed the 50% rule.
Upcoming discussion on Wind Direction 2 in the next video.
Invitation to subscribe to the YouTube channel and follow on Facebook for more content.
Transcripts
Gday and welcome back to Buildsum and this is part 4 in the series on
calculating wall bracing and now we're going to start looking at designing the
bracing systems and the first thing we can look at as far as that's concerned
is what we call Nominal bracing okay so just to recap so previously we worked
out the, the pressure that it's going to be applied to our wall and we know that
Wind Direction 1 had an area elevation of 43.553
square metres which gave us a total racking force of 47.908 kN
okay that's the force that is going to act on that wall and for wind
direction too we had 20.254 kN acting in Wind
Direction 2 so now we're going to look at actually designing the bracing to
resist that force and the first thing we have to consider is what we called
nominal bracing okay so nominal bracing is basically made up of what our
internal lining is so for using Gyprock, villaboard
or any type of lining boards our internal lining makes up our nominal
bracing so a couple of rules around that we can only use nominal bracing to
resist 50 percent of the total racking force in any direction and if
there's a panel size that's less than 450mm we can't consider it okay so if
you go to a section of wall let's left and less than 450mm long you can't
include that in your calculations okay and it should be evenly distributed
throughout the building okay other well that should be pretty normal
okay so the tables in the Timber Framing Code say that the capacity of nominal
wall bracing for single sided walls is 0.45 kN per meter and for
walls sheeted on both sides its 0.75 kN per meter so basically what
we have to do is work out the length of those walls in the building
then times it by the bracing capacity that will give us how much resistance
the nominal bracing is going to give us let's do that with our example house so
Wind Direction 1 is down the bottom here the wind's blowing against
the long side the house so that all the walls at 90 degrees to the Wind
Direction alright will be resisting that so yeah 90 degrees or the same
direction as the actual wind direction, I guess, now there the walls that are
actually resist it, Because the wall the wind will blow against this wall and
these walls will help resist the load if you know what I mean so the first time
we can look at is walls with one side sheeted only so they are your external
walls because in this case there's a cavity and then the brickwork okay so
I've got the two external walls and then I've got these two ones here near the
near the door so we just work out the length of those walls so Wall 1 which
is starting on the left-hand side the long wall, 7m long, Wall 2, which
is next to the door it's 1.1m long
Wall 3, 1.1m long and the Wall 4, 7m long so we just add them up
there's me a total length of 16.2m and we times that by
our bracing capacity per metre which was 0.45 for single-sided walls so that
gives us a total bracing capacity of 7.424 kN for
the single sided walls so then we have to do the double sided walls so here
we've got a double sided walls highlighted so all these walls on this
side of the building pretty much the same length so I'm just going to work
them out all together okay so 4 walls, 2.5mlong there then we've got
this wall here so one wall at 3.5m long there and then these two, so two
walls at 2.4m long gives us 4.8 so again times, 4 x 2.5 gives you 10
1 x 3.5 gives you 3.5, 2 x 2.4 gives you 4.8, a total length of 18.3m
18.3 times our bracing capacity for
double-sided walls for two sides 0.75 gives us 13.725kN so we add those two amounts together we
get a total resistance from our nominal bracing in wind direction one of
21.150kN so we can go back over. so we've worked at a
nominal bracing of 21.150 so we required
47.908 minus the
21.150 it's less than a half so we do not have to worry about the 50%
rule so we still require 26.758kN of
resistance in when Wind Direction 1 all right so that's Wind Direction 1
done in the next video I'll have a look at Wind Direction 2
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 don't miss out on
more great videos
関連動画をさらに表示
Calculate Wall Bracing - Part 5 - Design Bracing Systems - Nominal Bracing - Wind Direction 2
Calculate Wall Bracing - Part 3 - Calculate the Area of Elevation and Calculate the Racking Force.
Calculate Wall Bracing - Part 7 - Design Bracing Systems - Walls
Calculate Wall Bracing - Part 6 - Design Bracing Systems - Walls
Calculate Wall Bracing - Part 8 - Distribution and Spacing
Calculate Wall Bracing - Part 1- Getting started
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