H20 Truck Loading 1

[scanf1027]

I am designing a below grade concrete culvert. My question may be dumb, but the way the IBC states to distribute the load seems unconservative. Also, IBC refers to AASHTO, but I thought AASHTO specified a 32 kip pt load.
Essentially I'm modeling a 1' wide strip of my box culvert structure (walls and slabs). The truck path is in the direction of the top slab span. The IBC states to take the stated loads and spread over a 10' width. The lane load is 640 lb/ft in the direction of lane and a 26 kip/18 kip point load for shear/moment, respectively. I get a uniform lane load of 64 lb/ft and for the concentrated load (for moment) a point load of 1.8 kips. This seems unconservative. Any suggestions? I've attached a section of the culvert.

Thanks

 

[bridgebuster]

If you are designing what is technically a culvert - clear span less than 20' - you shouldn't use the lane load. Use the 16K wheel load with the required distribution and impact factors. Even if your span is longer you should still use the wheel load.

Check the CalTrans site; they used to have a culvert design example.

 

[dicksewerrat]

What are the dimensions of the box? Have the boxes built by reputable pipe manufacturer and delivered to site. They will build to your spec. H20 or what ever you say. Seal with open cell poly rope and hydrophilic grout.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[hmcrae]

I would assume your state DOT would have a standard for box culverts? TxDOT has a standard for almost every box you could need, although a modified standard is sometime used.