5 story basement (office)construction, your experience? 4

[IJR]

Pals

When it is one or two story down the baseline, you excavate a pit and use retaining walls against slides.

When it is 5 story(some 55ft (17metres)) down, economical solution probably will require 55ft(17m) piles all the way down. An alternative would be a wall anchored through the soil.

Both are expensive and I can not imagine the exavation after piling is done

My concern is when either the piles or walls have to be a part of the finished structure. The structure will be fully surrounded by soil when done, except for a few shafts down to the basements.

Please share with us your experience with such construction

Respects
IJR

 

[TLF1]

Havn't any experience with these deep structures, but you must consider uplift from the water table. You did not mention the ground water level either normal or high. Piles could be designed for uplift to counter flotation of the sturcture or counter the uplift with a really heavy structure.

 

[Taro]

The two most common basement excavation shoring methods I have used are:

1. Steel soldier piles with wood lagging and tiebacks.
2. Shotcrete soil nail wall.

Both of these methods require anchoring into the soil behind the wall so you may need to negotiate a temporary easement with the neighboring property owner. If the tiebacks or soil nails are not possible, you could use cross-lot bracing or rakers instead. But these braces are less desireable because they can interfere with the construction of the permanent structure.

 

[IJR]

TLF1

I did not have uplift problem in mind- I had Taro's kind of response in mind, in which retention of soil that deep is more important. Thanks for pointing out though

respects
ijr

 

[eric1037]

Have you considered a diaphragm wall?

http://www.nicholsonconstruction.com/services/walls.html

 

[PEinc]

Diaphragm walls should be a last resort if based only on cost. They are very expensive. There are usually other significant site problems that would be needed to make a diaphragm wall economical or needed. Taro's methods should be the first methods considered.