Sheet Pile Design as Concrete Stay-in-Place Form 1

[psnyder]

I am designing a project where I will be rehabbing an existing bridge. The existing 25 ft tall concrete abutments and wingwalls are not in too bad condition, but the beams and deck are not good. So, my colleague and I are proposing to save some money and drive scz sheet piling in front of the abutments/wingwalls up to the top of the beam seat and filling the void between the two interfaces with concrete. Additionally, the sheet piles will be braced at the top with angles and bolts through the existing concrete abutments, driven to a depth of about 15 feet for a total length of 40 feet, and either 27in or 33in deep precast box beams will be used.

In doing the design for calculating the required section modulus for the sheet piling, I was wondering if anyone had any suggestions of what specific design manuals and free software (for checking the hand calculations) that may be available, and if anyone had any other suggestions? Thanks for your help.

PAUL S SNYDER, P.E.

 

[FixedEarth]

Book 1: "Engineering Design in Geotechnics", by Fethi Azizi-Chapter 7.
Book 2: "Analytical and Computer Methods in Foundation Engineering" by Joseph Bowles-Chapter 10 or
Book 3: "Foundation Engineering" by A.R. Jumikis- Chapter 6. All three books are very good.
For software of steel sheetpiles, we use

http://www.soilstructure.com/sheetpiledesign.html

You may have surcharges, in which case the attached equations will be needed.

 

[PEinc]

It sounds like you are not designing a normal sheet pile wall. You are designing a concrete form. You need to determine the concrete pressures (a function of the concrete temperature and the rate of pour). You need to design form ties to hold the sheet pile form in place until the concrete hardens, after which, the sheet piling does nothing. Why not just use removeable, rentable, concrete forms instead of an expensive left-in-place steel sheeting?

http://www.PeirceEngineering.com

 

[amec2004]

>>Why not just use removeable, rentable, concrete forms instead of an expensive left-in-place steel sheeting?

I agreed.

Your description is not very clear. Will this sheetpile retain a wide rage of fresh concrete pour, with height >9' of concrete pour or just a small patch ?

If it's jsut a small pour, try to use ply wood forwork, or use Q-Deck if you don't want to do the formwork removal.

I had done a Q-Deck formwork design recently, the 3" depth VicWest HI-Bond can take concrete pour up to 2m.

You can apply temporary exterior diagonal brace and need not to get the embedded option.

Sheetpile seems to be overkilled for pure formwork purpose unless you have over 10' deep pour with a half space range fresh concrete active pressure behind the sheetpile.

anchor bolt design per ACI 318-11 crane beam design

http://www.civilbay.com

 

[bridgebuster]

The management doesn't like posting in mulitple forums. You should Red Flag either this on or the one in the Concrete Formwork forum.

 

[psnyder]

My mistake; as I should have been more specific and indicate that the sheet piles will end up as stay-in-place forms to serve as a component for the new abutment. They will not serve structurally by carrying the vertical load from the beams, as the existing abutment/timber piles will serve for that purpose, but rather more for scour protection and for the adjoining wing walls. The concrete load will govern in this case versus the soil load because the sheet piles will also be driven in front of the existing concrete wing walls as well.

The abutment is approximately 25 feet tall and 32 ft long. If I assume we use a Skyline Steel SCZ 22 - SCZ 30 sheet pile there is a height of 13.39 in. (width = 24.02 in) and we need approximately an extra 6 inches for our hammer for a total of roughly 20 in between the face of the existing abutment and the sheet pile. Therefore, the concrete pour will have the dimensions equal to approximately 25 ft (H) x 32/2 ft (L-24.02 in) x 20/12 ft (W).

Thanks to all so far for your comments. I look forward to further discussion...also, I made a mistake of putting on two forums. How do I remove the thread I started on Concrete Formwork engineering? I should note that I routinely check eng-tips for "engineering tips", but rarely comment. Been a good site thus far for getting pointers.

PAUL S SNYDER, P.E.

 

[psnyder]

I have not gotten any replies to this post, so I am reposting it:


My mistake; as I should have been more specific and indicate that the sheet piles will end up as stay-in-place forms to serve as a component for the new abutment. They will not serve structurally by carrying the vertical load from the beams, as the existing abutment/timber piles will serve for that purpose, but rather more for scour protection and for the adjoining wing walls. The concrete load will govern in this case versus the soil load because the sheet piles will also be driven in front of the existing concrete wing walls as well.

The abutment is approximately 25 feet tall and 32 ft long. If I assume we use a Skyline Steel SCZ 22 - SCZ 30 sheet pile there is a height of 13.39 in. (width = 24.02 in) and we need approximately an extra 6 inches for our hammer for a total of roughly 20 in between the face of the existing abutment and the sheet pile. Therefore, the concrete pour will have the dimensions equal to approximately 25 ft (H) x 32/2 ft (L-24.02 in) x 20/12 ft (W).

Thanks to all so far for your comments. I look forward to further discussion...also, I made a mistake of putting on two forums. How do I remove the thread I started on Concrete Formwork engineering? I should note that I routinely check eng-tips for "engineering tips", but rarely comment. Been a good site thus far for getting pointers.


PAUL S SNYDER, P.E.

 

[PEinc]

The scheme you describe still sounds like overkill to me. If you want to drive sheet piling in front of an existing abutment, you better make sure the sheet piling clears the toes of the existing footings.

http://www.PeirceEngineering.com

 

[psnyder]

Thanks for the response PEinc. I actually just finished my design for the sheetpile, front angle and accompanying anchor bolts, but would still appreciate further responses. Ended up using ACI347 equation for pmax for concrete loading rate (R) > 7ft/hr. SCZ 16 works since the top of the wall will be fully braced.

This design will ultimately save a ton of money versus either constructing new CIP abutments or moving the abutments further back for stub abutments/longer beams. Our surveyors have completed the site survey (top of vertical footer was exposed for each side), and I have existing 1930 bridge plans that show the layout of the footer. We just need to stay at least 6 inches away from the front to account for our hammer. We have done this many times in the past with shorter abutments with great success, but not for taller walls.

PAUL S SNYDER, P.E.

 

[psnyder]

I should reiterate the fact that these 40 ft long sheet pile sections will be driven to 15 ft below the surface leaving approximately 25 ft exposed.

PAUL S SNYDER, P.E.