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Should I worry about my building?

stacesimone

I live in Asia, on the top (26th) floor of a very thin building (about 400 sq-feet base). When I first moved here they had recently demolished the building to the left of this picture. Now, after having been here a year, they're demolishing the building to the right.

I have no expertise in architecture or engineering, but it seems to me these buildings might have provided some support to mine. There are plenty of buildings as skinny as mine, but I've never seen one standing alone.

Also, with the construction next door, there are tremors from 10am-6pm every day. My roommate doesn't mind them, but they make me and my cat very nervous. Am I being silly, or are there any signs of instability I can look out for?

Thank you all for reading.

 
Jun 18, 16 12:09 am
∑ π ∓ √ ∞

life insurance.

Jun 18, 16 9:08 am  · 
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curtkram

The neighboring buildings probably did not provide any support
You'd probably be happier if you didn't worry about it. However, if you want to worry, I'm pretty sure there have been cases where demolishing a building damaged the foundations of adjacent buildings.
For the time being it's ok for a building to shake a bit. We try to avoid that because it's uncomfortable for the occupants, but a steel structure can sway quite a bit before it gets damaged

Jun 18, 16 9:22 am  · 
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geezertect

With a 400 SF footprint, how do you fit in an elevator shaft and a couple of stairs?

I think you're pulling our chain.

Jun 18, 16 9:23 am  · 
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It's Asia - different codes. I'm guessing a pretty tiny 2000lb capacity elevator, and only one stair.

And probably a miscalc between SF and Square meters
Jun 18, 16 11:19 am  · 
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It has to be more than 400 sq.ft. but it doesn't look to be sq. meters either. 400 sq.meters would be a little over 4300 sq.ft.

The base would have to be structurally connected all the way to the ground. I don't have the plans for this building but I would be awfully concerned about its shear resistance / lateral force resistance and would have to scrutinize the rebar detailing. 

Jun 18, 16 3:29 pm  · 
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The neighboring buildings probably did not provide any support 
You'd probably be happier if you didn't worry about it. However, if you want to worry, I'm pretty sure there have been cases where demolishing a building damaged the foundations of adjacent buildings. 
For the time being it's ok for a building to shake a bit. We try to avoid that because it's uncomfortable for the occupants, but a steel structure can sway quite a bit before it gets damaged

They both provided some level of support. I can't ascertain how much from just these two photos. It looks like but I can't tell for sure, the building on the right might be supporting part of this building. It might be the way the photo are. With zero-lot line buildings, you do consider the adjacent abutting structures in the structural design. I am not sure but it appears to be a bit uncomfortable without appropriate lateral force resistance. There would need to be some checking on that for adequacy by architects and/or structural engineers licensed to practice in that area.

Jun 18, 16 3:48 pm  · 
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Non Sequitur

The buildings were not adding any support since you don't brace that way. The sway, if any, is highly due to wind load and is always present. I would bet the OP only started noticing it because they convinced themselves the demo was a contributing force and now they can't "un-notice" it anymore.

I see a similar false pattern recognition thing in my city. There is plenty of blasting for underground construction and people are claiming that cracks, which were most certainly always present, formed due to the construction eventhough they are several blocks away from the nearest sensors. I.e. They beleive the blasts are damaging their buildings so they go hunting for "evidence". 

Jun 18, 16 3:59 pm  · 
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When an adjacent building is removed on a zero lot line scenario can disturb soil supporting the foundation which can cause problem. Personally, I would recommend an assessment by a qualified professional. Disturbed soil condition can compromise the structural stability.

Remember, those buildings acts like retaining walls to the soil under the building. Removal of the building on the left side can destabilize and disturb the soil on the left side of the tall narrow building. 

I am not saying the soil had been disturbed to excessive level. Only a professional assessment by a qualified professional can ascertain that. 

I'm not there. I'm not a geotech engineer, either. 

Jun 18, 16 4:44 pm  · 
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N.TW

All we can say on this forum is hopefully the agencies, architects and engineers responsible for the demolitions have done the appropriate research and analysis to preserve the health/safety/welfare of everyone impacted by the project.

In the U.S. today it would be hard for me to imagine anything safety-wise could really be at risk in this type of situation. I can't speak for where you live in Asia.

As for my reading of the structural questions: would adjacent buildings have some effect on the lateral resistance of the structure? Probably on some level. But I don't see how the structure's integrity would depend on those adjacent buildings, unless they are physically, mechanically connected somehow. Plus we have no idea, from your photos, of the foundation systems of your building, and the soils design for this thing. We can only speculate on this very complex question.

If it would make you feel better, one approach might be to find out when your building was built, and research the seismic design standards for that time period. I think you would find that the tremors from blasting are nowhere near the level of shaking that building should withstand.

Although the construction might be annoying, I don't think it's worth being nervous about.

Jun 18, 16 5:02 pm  · 
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N.TW

:-)

I agree. We can only provide unqualified responses because there is not enough information, fact data, supporting professional documents and so forth.

All we can give is a gut feeling response.

Jun 18, 16 5:12 pm  · 
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no_form
"Personally, I would recommend an assessment by a qualified professional". RWCB. Glad you finally admitted that that is not what you are.
Jun 18, 16 5:50 pm  · 
 · 
∑ π ∓ √ ∞

Rikki, please, provide us with sketches, or it didn't happen. Show us how buildings work, please?

Jun 18, 16 6:32 pm  · 
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no_form,

I do not practice in Asia. I don't have the licenses in those countries. You are not a qualified professional. Most of the people on this forum are also not qualified professionals. They do not possess the required license(s) for that jurisdiction.

I am not interested in going to wherever the fuck this project is located at in Asia to assess this project properly. You can't do it from just photos. If I had to do it, first thing is find every documentation about the building and neighboring buildings and the documents regarding the demolition of the one building adjacent to the tall building. If necessary or prudent, a soil analysis and study for any form of settlement issue of the building. That's just the tip of the iceberg involved.

Since I am not doing that, I am not interested in investing that kind of time and expense. 

I recommend someone that is qualified in the applicable disciplines WITH the required license(s) as maybe required in that jurisdiction. 

There are two key engineering disciplines that would be initially applicable, geotech/soil type and engineering discipline and structural engineering discipline. With the two individual photos, I don't have enough information to say if there is a structural problem. 

curtkram, N.S., me, and N.TW all have valid points. NONE of us can be certain unless we have substantially more information than what is given. I'm only proposing a middle of the road prudence of assessing the structure. I wouldn't ignore the concerns raised but I wouldn't worry/panic, either. 

None of us has enough information to really answer the OP's question as it was written.

Jun 18, 16 6:51 pm  · 
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Rikki, please, provide us with sketches, or it didn't happen. Show us how buildings work, please?

No. Not on this thread.

Jun 18, 16 6:56 pm  · 
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no_form
"You can't do it from just photos." You mean like counting cmu blocks in a theater?
Jun 18, 16 7:02 pm  · 
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no_form,

The theater has nothing to do with this topic. The reason you can't properly assess such a project only on the photos is because the photos are not after the demolition of an adjacent building. Soil analysis can not be done without taking soil sample(s) from the site. There are things that need to be assessed involving on site stuff. 

Additionally, some of the records are not available in digital form except from the original architects/engineers. There are things that needs or involves on-site investigation.

Jun 18, 16 7:35 pm  · 
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Wilma Buttfit

Is it a kangaroo building? Does it have a big tail?

Jun 18, 16 7:40 pm  · 
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Non Sequitur
Maybe the adjacent building were the kangaroo babies and now that they've left the pouch via demolition, the mommy kangaroo is sad and cold, hence the sway.
Jun 18, 16 7:44 pm  · 
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LOL!

Jun 18, 16 7:46 pm  · 
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no_form
Hey Balkins, how many high rises have you engineered? How many structural engineering courses have you had? Are you a PE? Do you know how to read structural drawings? Have you ever read a soils report?

Remember when one guy on here wanted advice on a 1/2 mile long bridge spanning a river in Africa? Remember how your response was about calculating what size boards to use to buy a decorative wood bridges for a suburban backyard?

You know nothing. You're a fucking knob. Do something else with your life.
Jun 18, 16 7:57 pm  · 
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Without structural knowledge of your building, and a general location of "Asia", you must be not seriously real. I have no professional or other opinion on this question!

 

But, thank you for keeping the question alive.

Jun 18, 16 8:29 pm  · 
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.

Jun 18, 16 8:36 pm  · 
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stacesimone is the original poster.

Jun 18, 16 8:38 pm  · 
 · 
∑ π ∓ √ ∞

No_form asks the correct questions.

Jun 18, 16 10:11 pm  · 
 · 
∑ π ∓ √ ∞

Rikki, could you talk about, in detail, what it takes to bribe local officials?

Jun 18, 16 10:12 pm  · 
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nope.

Jun 18, 16 10:41 pm  · 
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Schoon

Non Sequitur nailed it. 

Rick:

With zero-lot line buildings, you do consider the adjacent abutting structures in the structural design. I am not sure but it appears to be a bit uncomfortable without appropriate lateral force resistance. There would need to be some checking on that for adequacy by architects and/or structural engineers licensed to practice in that area.

Structural engineers never design new construction to depend on existing buildings for "lateral force resistance." 

If your answer to a question would be "I don't know, ask a professional" then perhaps it's better to say nothing. 

Jun 19, 16 2:28 pm  · 
 · 
∑ π ∓ √ ∞

Schoon, thank you, that's what I was trying to get Rikki to demonstrate. New buildings need an independent footing/foundation. If anything, it's my understanding that the new construction, many times will have footings below adjacent existing footings, and the engineer will likely need to underpin the existing adjacent construction.

Jun 19, 16 2:42 pm  · 
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Schoon,

You can't design a zero-lot line building without considering the impact on other buildings. Ever heard of buildings pounding into other buildings under seismic load? Don't assume this building was properly engineered in the first place. China had a number of cases just in the last 5-10 years of high rise buildings just falling over. 

Zero-lot line buildings means the building may share common wall(s).

Jun 19, 16 2:51 pm  · 
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Schoon and b3ta,

Don't assume that is universal everywhere. In addition, there is a laws of physics (scientific laws) where removing removing an abutting building may impact soil conditions along the perimeter walls of a building. This is because the walls and foundation of building adjacent to the tall building may function to some extent as a retaining wall retaining the structural soil under the tall building. Remove the retaining wall and the structural soil may begin falling out due to erosion and gravity. 

Don't tell me engineers never fuck up. We have seen a number of instances of high rise buildings falling over in the past 15 years in China. 

Jun 19, 16 3:01 pm  · 
 · 
∑ π ∓ √ ∞

Wrong.

That would be party walls.

Zero lot line walls, and footings/foundations sit entirely on the property owner's side of the lot line, and footings cannot cross that lot line.

Party walls are built for the benefit of either party, and are typically subject to some kind of covenant. 

You cannot, for instance bear your floor/structure/roof on another's wall. 

Your new building must remain independent of the existing adjacent construction/structure.

Jun 19, 16 3:10 pm  · 
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∑ π ∓ √ ∞

Hence, underpinning. What soil? 

Diagram your nonsense.

If you can't draw it, it never happened.

Jun 19, 16 3:13 pm  · 
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I'm going to propose to the city that I can use neighboring building as structure. Balkins can't be wrong, right?

Oh wait...
Jun 19, 16 3:24 pm  · 
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Schoon

Rick,

I can assure you just from looking at the pictures that any apparent connection between those buildings is not structural.

Demolition is not a fast-and-loose process.  Professional engineers take measures to protect against the issues you are mentioning.  If you would like to assume the engineers doing the demo are incompetent or corrupt, you are welcome to, but calling for an independent structural engineer to verify the demo is safe may be edging on paranoia.

Also, thank you for letting us know that the laws of physics are, in fact, scientific.

Jun 19, 16 3:25 pm  · 
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Guys,

The tall building in the center looks like it was built in the 1960s or 70s. The other buildings were built earlier.... 1930s to 1950s. 

Also, don't assume the laws and practices are the same as they are in the U.S. This tall building isn't in the U.S., right?

Don't assume the engineers or the contractor did their job correctly. Remember those Chinese high rise buildings falling over in the past 15 years?

Jun 19, 16 3:38 pm  · 
 · 
∑ π ∓ √ ∞

Which Chinese building collapses?

Jun 19, 16 3:45 pm  · 
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Remember: https://www.google.com/#q=Chinese+buildings+falling+over

That Chinese apartment buildings falling over?

Albeit, it may be a small percentage of cases but it still happens. It is true buildings falling over is a small percentage of cases but they do exist.

Jun 19, 16 4:28 pm  · 
 · 
∑ π ∓ √ ∞

Now, does the situation you posted, one example I might add, look anything like the OP example?

I'm still waiting your diagram of hypothetical issues? Or is that more of your double speak?

Jun 19, 16 4:43 pm  · 
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Do you know how much your building weighs?

Jun 19, 16 6:53 pm  · 
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William Wynne,

This isn't my building. I'm not the original poster of this thread. I couldn't say exactly how much this building weighs aside from a lot. 

Any building I design, I could estimate weight to some degree from all the material and equipment systems throughout the building.

Jun 19, 16 6:58 pm  · 
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snooker-doodle-dandy

Rick, Go back to designing  opium dens....   These buildings are designed to handle earthquakes, so no way is it attached to the adjacent buildings.  There is a big fat  relief joint between it and the adjacent buildings.  That is why they are feeling the building sway back and fort with a trimmer. The footing is most likely a structural floating slab and again is separated from the adjacent buildings.  Not your residential  spread footing ,  Dude you have gone overboard on this one.

Jun 19, 16 7:27 pm  · 
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When snook says "Dude, chill." you know you've gone too far.

Jun 19, 16 8:25 pm  · 
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∑ π ∓ √ ∞

Rikki, is everything about you? Where in William's query, was he asking you a damn thing? You're a classic, text-book, narcissist.

Jun 19, 16 8:28 pm  · 
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poop876

Rick, you don't practice anywhere!

Jun 19, 16 9:58 pm  · 
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b3ta,

Reasonable presumption given how all of you are replying to me and how this forum tends to do the gang up on individuals thing like classic, text-book, street punk gangs. 

 

 

snooker, relief joints... ROFLMFAO. You either have significant massive sheer walls or have statically stable walls equivalent to the walls of machu picchu. I see virtually zero relief joints. Maybe an inch or so.... possible 

You need extreme static stability in order for the walls to not sway into adjacent structures. You need more than just a few inches. In wind, a 26 story building may sway as much as ~6". At the 5th floor (50-ft elevation), the building may sway +/- 1.125 inches give or take a little. In a massive earthquake on the order of Magnitude 7.0 to 8.0+ may cause this building to sway a lot more. As it is, the lack of any apparent gap between these buildings don't allow for much movement for earthquakes let alone load combinations of high winds and very large earthquakes. 

Jun 19, 16 10:28 pm  · 
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Once again Rick, you have no clue what you are talking about. You can't even get a small theater in Astpria right.
Jun 19, 16 10:44 pm  · 
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Astoria. Point still stands.
Jun 19, 16 10:45 pm  · 
 · 
∑ π ∓ √ ∞

Rikki, I like Stephen Lauf, he may hate me, and I him, but at least he has a body of work, can back his comments up, with a body of work, and doesn't complain - well, he seems to think people willingly giving their time should be paid for (fuck if I know) - but I digress. He doesn't pontify the way you do, and you have zero to show, no sketches of what you are talking about, just empty rhetoric, and seriously off the mark ideas. This dumb profession works in visuals, if you can't produce a drawing, or at least a napkin sketch of your thinking, you're nothing but a nattering nabob.

Jun 19, 16 11:09 pm  · 
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.

Jun 19, 16 11:25 pm  · 
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Rikki, I like Stephen Lauf, he may hate me, and I him, but at least he has a body of work, can back his comments up, with a body of work, and doesn't complain - well, he seems to think people willingly giving their time should be paid for (fuck if I know) - but I digress. He doesn't pontify the way you do, and you have zero to show, no sketches of what you are talking about, just empty rhetoric, and seriously off the mark ideas. This dumb profession works in visuals, if you can't produce a drawing, or at least a napkin sketch of your thinking, you're nothing but a nattering nabob.

b3tadine,

If you want a sketch, then bring yourself over. I'm not going to spend all that extra time to scan sketches and then upload it for something as non-consequential as an internet forum discussion thread.

I don't have any simple, seemless means of putting sketches up on the internet that doesn't require me to spend more than 60 seconds of additional time beyond the time to sketch it. I'm not interested in spending a bunch of time just to digitize (scan the images or otherwise) and upload it. The PC that I have does not have touch screen monitors that I can sketch on-screen. 

Jun 19, 16 11:52 pm  · 
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