One building, but has 2 or more independent structure 1

[hst22]

Hi, I am currently a third-year Civil Engineering Student from the Philippines.

Our professor gave us a project where we lay out our own 2-storey house floorplans and beam and column, and do a structural analysis on it. My professor challenge me to find out how independent structures of one building were done or constructed and how its analysis should be done as well. I did my research through the internet but it was to no avail. I also messaged different youtube civil engineers, and apparently, I did not get any reply. I do not know where I could find some valuable information. And now, I am really hoping that I could get some help from here. Thank you!

 

[dik]

It's basically very simple. You treat them as two smaller structures. The walls/columns separating them can be independent, that is, two walls/columns and they can be on the same foundation. This is common. This is often used when you have a large building and you need to break it into smaller sections for thermal expansion/contraction reasons. Also if you have a large building, depending on the jurisdiction, you can physically break it into smaller sections with firewalls between the sections. This may allow you to use a less restrictive fire resistance rating. You have to be careful that the integrity of the building envelope is maintained.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[hst22]

Thank you so much! It really helped me a lot as a starting point to further research about this. Thank you again & God bless you!

 

[dik]

You have to consider the individual components to require their own independent lateral resistance. It's very difficult to interconnect these items.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[hst22]

When interconnecting these two independent structures, I was thinking that maybe a cantilever beam will do (i have no basis since it is still difficult to find it) or do they have a different approach on this (perhaps, maybe some type of device that interconnects the two structures while allowing the lateral forces move the structures, independently?(I have seen this being done on mega bridges to interconnect the slabs, a long time ago from a show.)

I hope my question is really making sense. sorry about that

 

[dik]

You don't want to interconnect them if you can avoid it.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[hst22]

I have this floorplan of my classmate (I was permitted to use for this discussion) which our professor corrected (the red pen) in terms of the proper position of the columns and addition of the beam. He told us for our own convenience, to position the column in a grid pattern and this is a standard when considering an earthquake load. So that is how I asked him about the independent structure in one building.

I wanted to ask how do engineers make it possible that one building, with 2 independent structures makes it look like one whole structure from inside the building?
Same as this floorplan, what if I wanted the highlighted part of the floorplan to be an independent structure so that I do not need to align the columns (like how our professor suggested to do, but at the same time as I walk in the house there is no discontinuity? I am sorry if my question feels like a stubborn one

 

[dik]

Unless there is a need to design this as two buildings, it's too small and I would design it a single building. I dont know what the materials of construction are, but it could be designed in wood, concrete, steel, or CFS.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[dik]

The attached is a building I did years ago. The wide part and the narrow part have a joint at mid length. In addition, the corner part has a joint on each side. The analysis treated them as 5 separate buildings.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[hst22]

First,I really wanted to thank you for lending me your help through this forum.

It took me a while before I could reply to this thread, I am honestly not confident of my understanding of some of the concepts. I have to make sure that I could get the gist of it, so I emailed this discussion thread to my professor, and he explained that, as what you said,
I can design two adjacent structures independently (even placing in one footing - a combined footing). Since they're independent, I have to avoid interconnecting them structurally, but rather make sure that there is some shared access (shared hallways) between the two structures.

I also appreciate that you showed me an example of your work and honestly that "joint" kinda confuses me since you said that there were 5 separate buildings and they cannot be interconnected. Though I think it is not a part of the structural aspect, I still have to ask (since I forgot to ask my professor as well). By what that "joint" means?
I hope I am not causing annoyance to your part.

 

[dik]

There are independent columns and beams on each side of the joints with a clear gap between them. This was 40 years back, but I seem to recall a 2" or 3" (about 50mm) gap between all 'buildings'. The main part of the complex had a 40' clear height, and the front part of the building ('ground side' as opposed to the back part being 'air side') had offices over the loading docks. The joint is handled by a properly detailed expansion joint, secured to one side only. Roofing and structure are independent. If you could move one of the components away from the structure and put it in a field; it would be a safe, stable structure, all by itself. All 5 parts can move independently. The building was the largest (plan area) building I've done. Plastic design (a method of analysis, check with your prof) was used for the structure; it was the first time the company I was working for had used plastic design.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[hst22]

I made a rough sketch of your building. If I am understanding it correctly, the red lines are the 50 mm gap between these 5 structurally independent buildings,and this is where the expansion joints were secured properly.
I also checked out the plastic design, and I think that is on our Steel Design (for the Next Semester) however, I will still ask my professor about this.

Also, Sir, you are amazing, it has been 40 years and you are still sharp.

 

[dik]

...a lot less sharp. As memory serves, B1 and B2 had 40' clear height and B3, B4 and B5 had 30' clear height. The lower part in front of B1 and B2 is the roof over the offices, and the loading docks were located under the office space. Just a caution, many engineers don't use plastic design... I like it and have been using it for over 50 years, but it is not everyone's cup of tea.

An interesting part of the framing is the structure between the office and storage. I'd seen structure like the attached used for decorative framing at the Eaton's Center in Toronto (non-load bearing). I used the same approach for picking up roof (very high snow accumulation > 100 psf if memory serves and mech equipment weight and snow accum from it) and floor loads for the framing between.

I should have added the plastic moment for the 2 span cont beam on the bottom is 0.0858*q*l^2 and the elastic moment is 0.125*q*l^2... big savings.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[hst22]

I think I can picture the building now. Also for the plastic design, sorry to say but this is a bit advanced for me, however, if I will be taking steel design for the next semester and learn it someday (I would like to have a full grasp), I hope I could make another discussion with you someday in regard to this, and I think this is one is an interesting method. Still thank you for giving me this idea that I could think of someday

I have another question, although I asked about independent structures, I am wondering why did you opt for 5 structurally independent buildings? Is having a large column (that is the same size of two independent columns)a disadvantage? if so, I would like to know reason behind that? This may give me helpful insights.

Being in a forum, giving help,ideas and insights, You're still sharp, sir.