Building geometry 10

[hoshang]

Hi all,
Please find the attached image.
Do you think the proposed geometry acceptable regarding center of mass and center of rigidity considerations? FYI the red circle is the center of mass.

 

[BAretired]

As I told you before, I can't open your file of 27 Dec. 23 21:26. Can the west stair be moved south to the unused space in the south west corner? Can the Septic Tank be moved elsewhere? Can the east stair and elevator be moved south to make room for two additional parking spaces in the north east corner? These are questions which I prefer to leave to the architect.

The crossed lines locate the center of the rectangular part of the building. They have no other significance. The red circle does not appear to be anywhere near the center of mass. The center of mass appears to be at or near the blue circle.

 

[rb1957]

I guess the planning requirement for the parking spaces doesn't say they need to accessible, at least not without resorting to "chinese wood block puzzle" movements !?

I assume the purple lines (1.17m apart) represent the access ? on the top edge ? How does the top car get into it's spot ?

TLDR (sorry) ... is the purple circle the ground reaction (based on your soil pressures) ? If the soil pressure is uniform, won't this be at the centroid (where the diagonals cross) ? ... further to the "NE" (up and to the right). The red circle is the center of mass of the building ?? And you want these two to align ... wow, that'll take an enormous redesign ! You've clearly got a lot to move to do this.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[hoshang]

As I told you before, I can't open your file of 27 Dec. 23 21:26. Can the west stair be moved south to the unused space in the south west corner? Can the Septic Tank be moved elsewhere? Can the east stair and elevator be moved south to make room for two additional parking spaces in the north east corner? These are questions which I prefer to leave to the architect.

If you could open my file, you will find out that these options alterations can't be done.

The red circle does not appear to be anywhere near the center of mass. The center of mass appears to be at or near the blue circle.

As I told you before, I used AutoCAD tools to find the center of mass. I selected the slab only (and not the columns, beams, core walls).

I assume the purple lines (1.17m apart) represent the access ? on the top edge ? How does the top car get into it's spot ?

TLDR (sorry) ... is the purple circle the ground reaction (based on your soil pressures) ? If the soil pressure is uniform, won't this be at the centroid (where the diagonals cross) ? ... further to the "NE" (up and to the right). The red circle is the center of mass of the building ?? And you want these two to align ... wow, that'll take an enormous redesign ! You've clearly got a lot to move to do this.

Can you elaborate more on these?

 

[BAretired]

If you could open my file, you will find out that these options alterations can't be done.

Okay...that is as I suspected. Looks like you're stuck with an extremely poor parking arrangement.

As I told you before, I used AutoCAD tools to find the center of mass. I selected the slab only (and not the columns, beams, core walls).

That is what you told me, but I suspect you did it incorrectly. See below.

 

[hoshang]

but I suspect you did it incorrectly. See below.

Appreciate your cooperation. Now your point is clear. I should check it with AutoCAD.
These are the plans and sections:

The left stair is 3 flights.

 

[ChorasDen]

BAretired is being very helpful here, kudos to him/her. However, simply looking at the layout without even delving into it with any depth of analysis. I agree that the center of mass should be where BA notes. Unless there is some extreme mass at the bottom of the structure, it makes no sense that the center of mass would be locate in the lower triangular section.

Center of mass compared to center of rigidity is really only important for seismic analysis. What code are you referencing, and is this a check that is important to you?

 

[BAretired]

I don't know where the property lines are, but I'm wondering if the basement areas could be extended to accommodate more parking. I see no way to significantly improve the parking layout with the present basement configuration.

 

[hoshang]

I don't know where the property lines are, but I'm wondering if the basement areas could be extended to accommodate more parking.

Please find the attached image:

The hatched area is the new construction area. There's no way to extend the basement area.

 

[dik]

[ul]
[li]Is it possible to move the elevator 'back' to create a better traffic 'pattern' for accessing spots?[/li]
[li]Can the columns be relocated slightly to improve traffic flow?[/li]
[li]Can 'transfer beams' be used?[/li]
[/ul][ul]
[/ul]
It may increase the floor to floor for a storey, but may be less costly, or greatly improve parking. With employment at RJC, I worked with Ted Seaburg (sp) and learned how to layout parking spaces (decades back). For the latter problem about transfer girders, As an extreme, I used two 6'x9' transfer beams, full building length, to transfer the loads from a multistorey shearwall structure to a supporting structure at the lower level so the lower level could be used for parking. The apartment shearwall spacing was not an efficient spacing for parking stall width or the space below

Moving the lift back can likely allow you to provide a parking space in front of the lift. As it stands, if you have 7 parking spaces, you have 476 sq.ft. per parking space. In a well designed parking garage, this area reduces to about 300 sq.ft. per space including isles, ramps, inlets and outlets..

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoshang]

Hi dik,
Appreciate your help. Would you show these recommendations on the image?

Is it possible to move the elevator 'back' to create a better traffic 'pattern' for accessing spots?
Can the columns be relocated slightly to improve traffic flow?
Can 'transfer beams' be used?

 

[dik]

Maybe something like (don't know clearances required).

and it may require relocating columns slightly. Can you park cars against the North wall? or have/make clearance to park one between the stairshaft wall and the north wall, and park two cars in the remaining space, where one is currently parked. The parking layout is terrible and could possibly be improved. Are there parking experts you can contact? I know Ted, at RJC, would often consult with others on parking garage layouts to minimise the vehicle space requirements.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoshang]

Maybe something like (don't know clearances required).

It seems not appropriate (not consistent with Typical floor plan and violates 20% of total area opening requirement).

 

[dik]

20% for natural ventilation? I would not have a parkade in the basement without forced ventilation.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoshang]

20% for natural ventilation? I would not have a parkade in the basement without forced ventilation.

Your lift location will conflict with the opening in the Typical floor plan where 20% opening is a requirement (please have a look at attachments in my previous posts).

 

[dik]

That's required for the basement (parkade) too? With exhaust fumes, that could be dangerous. I haven't done a parkade in decades, but in some jurisdictions having 20% or 25% perimeter openings allows you to use natural ventilation, but not for an enclosed parkade. I don't know what the current requirements are. For upper floors, does that pose any issues for fire resistance?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[ThomasH]

Going back to the first question, I agree with others that the center of mass seems wrong. And the reason for the concern, I assume it is the seismic design?

As for the parking layout, I would go so far as to say it is useless. You can't have that number of cars in the basement and make it work. Where I work I have colleagues that works with this type of questions. You can input a layout with cars into a software and test if you can get any car out of the basement independently of all the others. But I don't think anybody needs software to see that in this case it won't work.

My first thought is to not assume that the car must be parked parallel to the grid lines. Rotating some of the cars might help you. But I still think you need to loose at least one car.
Another thing is that the cars seem to be about 4.7 m long, the gap between the front of the hydraulic ramp and the column is 3.7 m. Depending of the design of the hydraulic ramp, will there be a problem to get a car in there?
Dik had an idea to move the ramp upwards towards the facade that you didn't like due to opening requirements. But now you have an opening in the lower (inclined) facade, what is the difference? And I can't quite see the columns as impossible to move.

Maybe you have nothing to do with the parking and you only interest is the location of the mass?

 

[dik]

In the last 50 years, I've been involved with about 50 parkades, including the design layout. This is one of the worst configurations I've seen. My suggestions were not to design it, but to offer some things to consider in the re-design. The two environments have to be separated; there is no reason to have the basement (parkade) connected to the rest of the building and many reasons not to. I've never been involved where the entire building space is part of a multipically connected floor space.

I just thought of it, but that large opening may have a significant effect on the seismic design. This is in particular if the area is high seismic. There are lots of things that don't seem to 'add up'.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[rb1957]

your post from 29th Dec (@ 22:23) confuses me (but then I don't read building plans much) ...

It looks like your plan views show each floor in succession ... two underground parking (how accessed ?), then ground level (some lucky guy gets street level parking ... or is this the lift, access to lower floors ?, which makes the block puzzle for cars much worse ??), then an empty floor (??) then a typical residential floor with three apartments (15 apartments in total ? so 15 cars required ??) ... what's the vacant square in the middle of the residential floor ? (if services, I'd've expected this would go down to the basement, or maybe street level ?) I don't understand the side elevation ?

Is the problem that the residential floors overhang the basement (foundation) ? So when you evenly load the residential floors and if you evenly load the basement then you have a mismatch ?

Where is this ? The apartments look very small ??

Maybe you're trying to do too much with this small parcel of land ?

Maybe have more parking at street level, or is this allocated for shopping ?


"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[dik]

Thanks rb... more things that don't 'add up'.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[dik]

Part of the project with the transfer beams included an underground loading dock. I located the columns supporting the loads over the loading dock using turning curves I developed for a tractor semi-trailer. I mocked up the columns in plywood and located them on a parking lot and hired a truck and driver to see that the locations worked. That was incorporated into the real layout. This was for the Cornwall Centre in Regina, Canada.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik