Nearly completed high-rise collapses in Shanghai 4

[GalileoG]

HONG KONG (Reuters) – A 13-storey residential building under construction in Shanghai collapsed Saturday, killing one worker and highlighting the dangers of shoddy building in fast-urbanising China.

The building, in the outskirts of the city, collapsed at around 6 a.m. (6 p.m. ET) with one construction worker killed, the official Xinhua news agency reported.

The block of high-rise residential flats was shown toppled onto its side in a muddy construction site, in footage from Hong Kong's Cable Television. Exposed pilings stood in the remains of the building's foundations.

It appeared to be almost complete with fitted windows and a finished, tiled facade. Other similar-looking blocks in the same property development were still standing nearby.

Shoddy construction and the use of sub-standard materials is a concern in China's construction sector as the country scrambles to build out cities and finish massive infrastructure projects to keep pace with fast economic growth.

Construction-related accidents last year included the collapse of a steel arch on a new railway bridge, which killed at least seven and a crane which fell on a kindergarten killing five.

The collapse of dozens of schools during last year's Sichuan earthquake, sometimes when buildings around them withstood the tremor, also led to a wave of public outrage about corrupt officials and construction firms.

Source:

http://news.yahoo.com/s/nm/20090627/wl_nm/us_china_building

Pictures:

http://img2.cache.netease.com/cnews/2009/6/27/2009062713100745a4b.jpg

http://img4.cache.netease.com/photo/0001/2009-06-27/5CQIQQA700AN0001.jpg

http://img2.cache.netease.com/photo/0001/2009-06-27/5CQLNCTL00AN0001.jpg

http://img2.cache.netease.com/photo/0001/2009-06-27/5CQLNCTL00AN0001.jpg

http://laiba.tianya.cn/laiba/images/10243577/12460615620825065124/A/1/m.jpg

http://hk.apple.nextmedia.com/images/e-paper/20090627/large/RTR_P_N0752.jpg

Clansman

If a builder has built a house for a man and has not made his work sound, and the house which he has built has fallen down and so caused the death of the householder, that builder shall be put to death." Code of Hammurabi, c.2040 B.C.

 

[hokie66]

One worker was killed, several managers will disappear.

 

[Bausk]

Seems like a negligent lack of geotech investigations.
Have any engineering details been published?

 

[PSlem]

Looks like it had cylinder piles. This pic explains it better than the previous ones. Looks like slope failure pushed it over.

 

[Ltdog]

I think that the nearby constructing underground park and rainstorm cause the foundation collapse,then the piles of the building were sheared to destroy and the building was overturned.
Besides I think the construction isnot shoddy.

 

[csd72]

Those piles appear to be unreinforced, I would expect some reinforcement in piles for a building of this size to take wind/seismic forces.

The rest of the building looks fine, how many buildings are capable of falling over and remaining in one piece?

PSlem,

It is unlikely that the building was pushed to failure by the soil as the soil is only very low and the weight of the building will be many times this. I would expect that the soil you see is from a circular rotation failure of the soil resulting from the building toppling over.

As always, these things are never clear cut. It would be interesting to see the results of the investigation.

 

[Ron]

Agree with csd72 on probable failure mode. Not slope push.

Anything we have is purely speculation, but would look at bearing failure on leading edge.

Piles look short...obviously didn't have enough tension capacity for overturning moment.

 

[cooperDBM]

The slope failure of the pile beside the building probably occurred when the building hit the ground from the resulting mini earthquake.

 

[BAretired]

The good thing is there was enough space between this and the next building so that it didn't start a domino action.

BA

 

[hokie66]

I wouldn't have much confidence in the other buildings.

 

[racookpe1978]

No rebar in the broken concrete piles.

No "slab" or floor structure in the lowest building basement: The building entry floor appears to be resting directly on the mud itself.

 

[dik]

I guess they make their buildings like they do their pipe!

 

[msquared48]

They were going to use the buildings to assemble Chinese toys to ship over here.

This is the Chinese version of "rollovers".

It looks like there was no basement - the grade beams appear to have been at grade. Consequently, the building CG was much higher, amplifying any settlements and associated OTM due to gravity loads that never should have occurred.

Mike McCann
MMC Engineering

 

[ishvaaag]

On what seen in the photos above it seems excessive settlement from one side caused tilt and breakup of the unreinforced piles. That the building wouldn't sreak whilst falling says it is better than its foundation. And without seeing more, for such vast settlement one would think as maybe short piles and ... maybe excavation on the far side? It would have been wedge failure.

 

[csd72]

How much trouble are they going to have putting people in those other three buildings?

 

[Ltdog]

All?
The pile adopt the high-strength prestressed pipe pile.
attached for you information

 

[Ltdog]

All?
The pile adopt the high-strength prestressed pipe pile.
attached for you information

 

[ishvaaag]

All works togeter. Surely the entire suppression or collapse of the farside of piles was not an hypothesis. Hence no surprise failing under forces much higher than those envisaged.

 

[rb1957]

for whatever reason, maybe this is a case of "just-in-time" collapse ? (before anyone got hurt)

 

[racookpe1978]

The wet dirt "uphill" from the failed building is still sliding "downhill" with a classic "half-moon" scarf near the road.

They were lucky it fell into an empty lot with no people, and not backwards into the roadway.