Building Ultra Tall on London's Clay

[mulattokid]

^ He is right again...I have visted both ans got them the wrong way round. Re Salisbury: " And brilliant it was; for a start, the water meadows where Bishop Poore decided to build his new cathedral had very little in the way of firm ground to support the weight of the structure. It is estimated that the massive tower rests on only 4 feet of gravel foundation. "

http://www.britainexpress.com/counti...-Cathedral.htm

[mulattokid]

Originally Posted by dronkula

I, probably incorrectly, always through that Dubai was kinda built on sand?

" It is a foolish man that builds his house on sand " The Good book (somewhere)

[RoryT]

Originally Posted by gothicform

you have misremebered the cathedral i think. that is winchester cathedral which was at the beginning of the 20th century collapsing. investigations by architects found it was built on foundations only 6 feet deep with a reed mat under it that kept it floating above a swamp!



in other words, one man laid the foundations for the cathedral underwater. a huge achievement that made him one of the most famous people in the country being awarded a personal pension, either by the king or parliament, i cant remember which whilst becoming a member of the royal victorian order and being a commoner was unheard of. i believe that walker died of spanish flu at the end of ww1.

Originally Posted by MercuryRise

now thats a pub quiz fact.

Fook me, im not coming to your pub quiz

[Bulldozer]

Another example of a building with foundation problems is the Leaning tower of pizza (or now that Professor Burland from Imperial college London has helped them sort it out after years of trying, the not so leaning tower). Professor Burlands one of the worlds top experts on Geotechnics.

When you dig holes in the ground allsorts of thing happen to it. If you dig abig hole the ground can swell up in the middle of the hole as the long term squashing effect of all the material excavated is removed the ground rebounds. Putting a huge heavy building on clay can have longterm consolidation effectively squeezing the material out from under it, if its soft material.

Piles transfer the load by both skin friction and end loads (unless debonded by sleeving them on the shaft which is done round the tube tunnels to avoid loading the tunnel walls).

Also Londons a giant dish with clay, sand & gravel, water and Chalk in at differing levels. (may be other layers as well my geologies getting sketchy now after a few years).

[mulattokid]

Originally Posted by Bulldozer

Also Londons a giant dish with clay, sand & gravel, water and Chalk in at differing levels. (may be other layers as well my geologies getting sketchy now after a few years).

That is why distant earthquakes are amplified in London like that one recently. The whole dish of mud wobbles like a jelly.

[RoryT]

and you can get liquefaction!

this Geography degree im doing is working

[mulattokid]

True,but you can get liquifaction anywhere...even a cracked watermain or sewer can cause that.

[RoryT]

so you dont need ground movement for liquefaction to happen?

[mulattokid]

Yes you do; vigorous shaking, but Its more common on sandy soil rather than clay.

http://en.wikipedia.org/wiki/Soil_liquefaction