Anchored Sheet Pile using "Short Sheet Piles"
Anchored Sheet Pile using "Short Sheet Piles"
(OP)
I'm currently designing a tieback system that will utilize a "short" sheet pile wall about 45' away from the main wall. The main wall is adjacent to a commuter railroad. The design criteria recommends to use the USS Steel Sheet Pile manual (which is similar to the more recent pilebuck manual). I'm trying to follow the methodology used in example 4 of the manual.
My tieback anchor is located 1.5' below the top of the sheet pile wall. Passive Pressure is 400psf/ft and active is 35psf/ft (F.S=1.0). For the design of the "short" sheet pile, I found that my point of zero moment occurs at a very shallow elevation (2.25' below top of wall). The anchor force that can mobilized at that depth is much smaller than what is required. Due to the constraints at the site, I cannot move the anchor location any lower than 1.5'. If I make my sheet pile wall deeper, I can mobilize enough passive to match the required anchor demand but end up with a moment at the base of the wall.
Is having a moment at the base of an anchor wall valid? The situation above is almost like a pile undergoing lateral movement since the anchor is relatively close to the top of the wall. Does anyone think doing a Lpile run treating the sheet pile wall as a pile worth it?
thread255-69993
My tieback anchor is located 1.5' below the top of the sheet pile wall. Passive Pressure is 400psf/ft and active is 35psf/ft (F.S=1.0). For the design of the "short" sheet pile, I found that my point of zero moment occurs at a very shallow elevation (2.25' below top of wall). The anchor force that can mobilized at that depth is much smaller than what is required. Due to the constraints at the site, I cannot move the anchor location any lower than 1.5'. If I make my sheet pile wall deeper, I can mobilize enough passive to match the required anchor demand but end up with a moment at the base of the wall.
Is having a moment at the base of an anchor wall valid? The situation above is almost like a pile undergoing lateral movement since the anchor is relatively close to the top of the wall. Does anyone think doing a Lpile run treating the sheet pile wall as a pile worth it?
thread255-69993





RE: Anchored Sheet Pile using "Short Sheet Piles"
RE: Anchored Sheet Pile using "Short Sheet Piles"
Your description of the problem is very confusing. Why are you worrying about the point of zero shear? Why can't you develop enough anchor force with an anchor located 1.5 feet below the top of the sheet pile wall? Is the anchor angled downward? Are you concerned about the anchor pushing back the top of the sheet pile wall? How high are both sheet pile walls? Do you have difficult soils? In my experience, Lpile is not normally used to design sheet pile walls.
The US Steel Sheet Pile Design Manual IS the Pile Buck Design Manual. The Pile Buck Manual just has aditional information.
Other than that, I'm not sure just what your problem really is.
RE: Anchored Sheet Pile using "Short Sheet Piles"
RE: Anchored Sheet Pile using "Short Sheet Piles"
that is what I would have said before reviewing the replies to date