3 Sided culvert 12+ m span

[Mixtli]

Hi there,
This culvert has an overburden of 2m and therefore the wheel loading from ONT truck has to be spread by using a pyramid which base is B=b+1.75H on each direction.

Now, S6-14, 6.12.6 states the following: "When distributed wheel loads from two or more wheels overlap, the total load of those wheels shall be uniformly distributed over the smallest rectangle that includes their individual areas...". A colleague and me have been debating as how to interpret this part, I included an image that is self explanatory, so the question is: is it w in X, or w1 in Y?

Thanks a lot

M.

 

[bridgebuster]

Go to the attached. It's a Caltrans example. On Page 6-31 & 6-32 it shows how to compute the loads for overlapping wheels. The AASHTO method can't be that much different from the spec you're following.

 

[Mixtli]

Hey bridgebuster, thanks a lot,
this manual is from 1992, and the calculation of traffic pressure is the whole tandem load divided by it's area, as X on my post.
Any chance the way of designing has changed for any reason since 1992?

Cheers

T.

 

[bridgebuster]

You're welcome Mixtli. The AASHTO LRFD spec has a procedure for determining the size of the rectangle due to the live load on buried structures. The procedure in the Standard Specs is more straight forward but I imagine the resulting areas are similar.

 

[robyengIT]

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