Malls are usually multiple stories. Couldn’t you do all the plumbing on the first floor to avoid going underground. And then add structural reinforcement at the first floor to prevent higher floors from collapsing / sinking? Yeah for egress you’d have to put the bedrooms along the exterior walls. But I’m sure you could still get plenty of use over the space which does not border an exterior wall both as part of the unit and as part of some shared community area.
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jaybone@lemmy.world 3 months ago
j4k3@lemmy.world 3 months ago
Watch when an old mall is demolished, the structure and the way the heavy equipment is used. You’ll start to see the issue better. It UA usually sketchy business to demolish because of the spans involved. It is more like light bridge construction than it is a typical building. It can’t be demolished incrementally like taking out bites of the structure and working across. The ones I’ve seen drop the roof first and clean up what remains.
Only an engineer can really say one way or another, and every building will be different. However, I’m willing to bet the load bearing structure is specialized and unique to the application. I doubt there is any flexibility for repurposing more than 10-15% outside of the tolerance you see utilized. It is like the question why can’t a Honda Civic perform like a Bugatti. Technically anything is possible if you point your money machine gun at it in a currency downpour, but is it still a Civic when a Bugatti is cheaper?
The smarter option is likely to demolish the light structure of the department store and build a proper apartment building that is then attached back onto the mall corridor.
idiomaddict@lemmy.world 3 months ago
Is a mall on Black Friday ( in the mall heyday) really lighter than a residence of the same footprint? Or is the average weight over time more important than a dozen hours every once in a while?
j4k3@lemmy.world 3 months ago
The more open a floor plan appears, where there are not large support columns, the lower the weight bearing capacity will be in general.
With something like modern skyscrapers that appear to have open floor plans, there is a massive structure somewhere within the design. The structure is usually in the center built around the elevators and stairs, although there are other methods too. This structure is engineered for the specific loads of each floor and the total structure, along with various environmental factors such as weather. Like all structures, this starts with a foundation that is large enough for the designed load with a small margin of safety added. The cost of the foundation is directly related to the weight bearing capacity. No one is building structures with substantial extra unused capacity. Likewise, people like the aesthetics of open indoor spaces. This involves designing a structure with the minimal amount of load bearing capacity so that it does not need support columns throughout for the roof and upper floors. This particular aesthetic constraint means that the total load bearing capacity of department stores is very close to what you see in a typical store. If you start adding a bunch of walls and furniture to subdivide this space, there us absolutely no chance that the structure could handle the load. Even if you would like to add support columns, the foundation is engineered for the load. You can’t reinforce something like this in a cost effective way. The size and depth of the pad, rebar density and structure all must be substantially different. You’re likely to need piles or other features that tie in the structure to deeper bedrock elements of the underlying earth.
idiomaddict@lemmy.world 3 months ago
I guess I’m picturing a mall with lots of support beams in the stores themselves, but not many in the hallways. I wonder if my local mall growing up was originally built for a different purpose. I can’t really picture any other malls, but I’ll keep an eye out when I visit a different one.