Temporary Sheet Piling Problem

[RustyDuster]

Hey Everybody,

A little background about the project: I'm currently working on temporary sheet piling for staging construction of a new culvert. The depth of excavation is 28' (1.5H:1V slope) so our plan was to use one or two rows of a whaler type system. Recently, we've received soil boring reports for the area. Needless to say, this area has some extremely poor soil. It's basically all fat clay (Cohesion = 370 psf). From just doing a quick check from the 1985 Steel Sheet Piling Design Manual (p. 40) on stability, I've come to the conclusion that this tall of a wall will fail miserably.

Actually, from what I've calculated I can only handle about 10.5' of the excavation before failure will begin.

Since this is a temporary case, does anyone have any ideas about how to resolve this? Any ideas that I can test out would be greatly appreciated. I'm currently using the Sheet Piling Wall 911 program to confirm what I'm finding out in my own calculations.

Thanks,

Matt

 

[FixedEarth]

With 2 level anchors or struts, you will need to use the Peck trapezoidal earth pressures instead of a triangular pressure distribution. The critical check will be when you excavate to install the 2nd support. Try Soil Structure Sheet pile program.