sheet pile design

[2rainman]

Would someone be able to estimate unit costs for a sheet pile design i have? This is a permanent retaining structure on a lake where i would backfill behind the wall with gravel and construct a concrete walkway over the gravel (walkway is for pedestrians so not load bearing). The calculations were done with assumptions about piles driven in sand with granular backfill. I designed a 14' total height sheet pile with 6' depth of penetration. wall length is about 450 linear feet. i calculated the maximum moment to be about 5 kip-ft and then a section modulus around 2.05 cubic inches. Was afraid the section modulus was too low (sheet pile might face problems with bending?) so i increased it to 10 cubic inches (the thickness of the wall would also increase which would improve resistance against rusting). Based on this i chose a SZ-15 section (I am using cold rolled sheet pile). Would anyone know approximate unit costs for the sheet pile and maybe delivery costs? I'm finding $40/linear ft in places but wanted to make sure. Also, does anyone have recommendations about type of gravel i would use and then maybe unit costs for that?

 

[cvg]

contact
skyline steel

http://www.skylinesteel.com/

LB Foster

http://www.lbfoster.com/

 

[DaveAtkins]

That number is way too low. I would use a ballpark figure of between $700/LF and $1,400/LF.

The walls I design, with 50' long sheets, waler, and tie rods or soil anchors generally cost between $2,500/LF and $5,000/LF.

DaveAtkins

 

[cvg]

agree with Dave
I have $600 per linear foot ($50 per square foot), 12 foot long piles, no anchors, installed in the dry. Price does not include general conditions, overhead, bonds, insurance, profit or taxes. you should get a budgetary quote from a supplier or a contractor. price also does not include cutting piles to length, driven to final elevation.

 

[PEinc]

2rainman, check your design. An 8' high (exposed height above dredge line) cantilevered wall with only 6' of embedment, along a lake, sounds like it might not be sufficient. Also, if you have pedestrians along the wall, you could possibly also have vehicles, like ambulances or fire trucks. Consider designing for some vehicle live load behind the wall. Any free-draining gravel backfill should suffice.

http://www.PeirceEngineering.com

 

[oldestguy]

Agree with PEinc. Are you allowing for possible future dredging in front? Consider tie backs to dead men, etc. to save on pile length and for more security.

 

[Okiryu]

PEinc or OG, perhaps this is a simple question but, given this is a lake site and the foundation soils are sand, and although good drainage material will be placed behind the wall, do hydrostatic pressures still need to be considered behind the sheet pile? Just noted that PEinc mentioned "Any free-draining gravel backfill should suffice", so I was wondering about how do you consider hydrostatic pressures in this case.

 

[PEinc]

Does the water level in the lake vary significantly? If so, over what time period?
If the lake level does not vary except over a long time period, the water on both sides of the wall should be fairly even and there would be little or no unbalanced (lagged) hydrostatic pressure. However, if you are installing the SSP and then backfilling behind the SSP, it is wise (cheap insurance) to backfill with permeable soils or clean crushed stone.

http://files.engineering.com/getfil...-4dda-bc72-422f6880df1b&file=Jet_Filter_1.pdf

http://www.PeirceEngineering.com