Concrete Sleeper Deflection 1

[Mark1991]

Hi All

Doing a design for concrete sleeper retaining walls, pretty comfortable with most of the design

But I am curious what deflection limits you've used for concrete sleepers.

AS 3600 gives a limit of L/250 for concrete elements, but AS 3600 is intended mostly for building structures.
ACI 318 gives a value of L/180 for roof top slabs, likely as deflection isn't as critical for rooftop slabs

I have seen L/125 used (similar to a commercial steel roof) but haven't really found any literature to back it up

Cheers

 

[BAretired]

Are the sleepers cantilevered from a foundation? Provide a cross section.

BA

 

[Mark1991]

Sure, not a cross section but an image of the typical construction. (see below)
very common for residential subdivisions in QLD.

Soldier pile steel post with concrete sleeper lagging.
I'm not worried about steel post deflection, I've got a limit there I'm happy with; just the sleepers between post

http://www.aussieconcreteproducts.c...-and-Galvanised-Steel-Posts-Springfield-2.jpg

 

[BAretired]

It may be common in Queensland but not in my neck of the woods. I wasn't thinking so much about steel post deflection as the high passive pressures that would develop if the soldier piles do not penetrate deep enough below grade.

The piles appear to be pretty closely spaced. Deflection of concrete lagging is purely an aesthetic consideration. L/180 seems reasonable for long term deflection.

BA

 

[Mark1991]

I thought that might be the case, always interesting to see different methods that become common in different regions!

That is also my line of thinking, L/180 keeps the limit to approx 9mm for a 1.6m long sleeper bay and that number sits well with me

Appreciate the reply, helps confirm I'm following the correct train of thought