Shear Design of Laterally loaded piles

[GRADSTRUCT]

Hi All,

This may be more to do with Geotechnical Engineering than Structural, I thought I would still ask here since my Geotechnical knowledge in this area is quite limited.

I have a laterally loaded pile which is in the vicinity of an adjacent rail line where the natural ground level is about 5m lower and therefore I ignored this top 5m length and calculated the socket depth required from this level (total depth = 5 + 2 ~ 7m). On site they found that there is rock from about 3m off the top and they have requested we look into alternate designs that wouldn't require them drilling down 7m (about 5m into rock).

I was thinking of having a couple of grouted anchor rods drilled to this depth which would take out the large moment in the pile through tension in the rods. But how would I resolve the shear force at the top of the pile.

I suppose I should check if the soil to the side of the pile can take the lateral loads? and check the deflection of the pile? and explore the load-deflection effect? Has anyone done something similar? I would really appreciate if anyone could explain this to me.

thanks a lot

 

[HTURKAK]

@GRADSTRUCT (Structural);

The title of the thread (Shear Design of Laterally loaded piles ). As far as i understand , the problem is drilling down the rock around socket depth 4.0 m .

I assume the retaining wall will have an effective depth (5+3+1) =9.0 m foundation will be composed of tangent piles ( drilled shafts ) . The diameter below the ground level should be in the range of D=1500 mm and above , conventional RC retaining wall . The tip deflection will be still a problem for rail line with this set up..

I would go with gravity retaining wall (counterfort retaining wall ) rather than piling .

My opinion only.


According to the grace of God which is given
unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. . . .
I Corinthians 3:10

 

[Lomarandil]

As HTURKAK hinted, sensitivity to deflection will significantly affect your approach (since the shear capacity of the soil/rock almost always governs over the shear capacity of the structural element, and shear capacity of the soil/rock is based on how far the pile can move while serviceable).

Please provide some more detail about this pile. Is it in fact a retaining wall structure, supporting a large monopole tower, or supporting something less sensitive?

 

[CuriousBearcat]

GRADSTRUCT: I have done something similar - do you have the Structural Engineering Handbook by Gaylord & Gaylord? They have an entire chapter on laterally loaded piles that I have found useful. With some changes, it can be implemented for your purpose. The specifics would depend on your project and layout.

-Just a curious engineer