Underground Parking 3

[JAE]

I've got a potential project where there will be two-stories of underground parking below a 5 story bulding.

I'm pretty sure I'd like to have cast-in-place concrete perimeter walls for this two-story basement. However, the walls will extend out to the property line, or perhaps out to the street curb line under the sidewalk and I was wondering:

What would be some feasible, economical ways to construct this in-place without digging a huge hole beyond the garage footprint? I know how to design the walls in-place - what I'm looking for is constructability means and methods. I've done concrete soldier piers before, but only for a single, 16' deep excavation. Sheet Piling?
Dig down and tie-back as you go?

And with those methods, what I'm curious about is waterproofing. For my soldier pier project, we added drainboard between the piers and cast an integral wall across the pier faces, draining the wall to a perimeter pipe under the wall. We then used a "negative" integral waterproofing on the inside face of the wall.

I'm just not as confident with a two-story condition, though.

 

[JAE]

Thanks for the link. One question - How can you ensure that the sheet pile, in and of itself, will prohibit water from seeping through the seams? The link seems to address this in one of the publications, but I would still worry about leakage and rusting/deterioration long-term.

 

[SlideRuleEra]

JAE - Steel piling (H piles & Sheet Piles) last a lot longer that many people believe. See "NBS Monograph 58, Corrosion of Steel Pilings in Soils" at the bottom of this page of my website

http://www.slideruleera.net/Steel-Piling.html

My experiences in working on 40 to 60 year old bridges and power plants agrees with that.

http://www.SlideRuleEra.net