Thursday, November 25, 2010

Rapid Building Assembly in China

This is a merry exercise in pre fabricated building and certainly demonstrates what can be done.  Generally it is always better to raise a building on site as quickly as possible.  I am more impressed watching a handful of men raise a concrete slab building one story at a time in a few days for each floor.

The real breakthrough is to build using stress skin panels that also retain design flexibility.  The problem is actually solved, except it is sitting on the shelf still.  That also could go to lock up in a couple of days.

A little design work and these metal frame structures will still be fine.  And in a country that is in a housing boom unlikely to end until every premodern structure has been either converted or torn down, this type of work can assist.

NOVEMBER 12, 2010

Ark Hotel Construction time lapse building 15 stories in 2 days and rapid construction of the Broad Pavillion at the Shanghai expo

Comment from

Rather amusing, to say the least. I think perhaps "raising a building in 2 days" might be better put. As I understand it, all those pre-fabricated components had to be built up externally, and moreover, the whole of the interior - plumbing, electrical, HVAC and so on might have been (probably not) installed in the same 2 days - but more likely followed in the weeks beyond. Maybe not. One thing is for certain, there were at least 10× as many workers working on the building than is average here in the States.

And its probably a good thing that this is done this way. China has pioneered "thinking of how to use LARGE groups of people in parallel", or nearly so. It wouldn't surprise me at all if there were 40 workers, 24 hours a day, per floor. So, working that guestimate backward: 

Estimate construction labor

peop.       peop.       peop.      Persn
Day         frame      interior  finishing                 hours

1             100         100              0                        4800
2             100         200            50                        8400
3              15          300         100                         9960
4                5          200         100                         7320
5                5          100         100                         4920
6                0           50            50                         2400
6                0           25            50                         1800

person-hrs 39600

person-days  4950
 person-wks   990

So... that's a lot of labor, in high concentration. The majority of the real labor-of-construction would appear to be happening in factories elsewhere. To bend metals, to make the "parts", to get things staged to be shipped and off-docked on site. I wonder how it compares to "regular" on-site framing, build-out, and finishing? 

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