Live load differnces

[dicksewerrat]

What is the difference between H-20 traffic load and HS-20 traffic load? The size and weight of the truck?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[bridgebuster]

H-20 is an 8k axle and a 32k axle, spaced at 14'
H-20 adds another 32k axle, with a variable spacing of 14' to 30'.

If you're not designing a bridge, use a 16k wheel load, plus impact if necessary.

 

[dicksewerrat]

OK. Thanks. We are designing liners for pipes under roads. I will continue to use the HS-20 unless they ask for the HS-25.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[dicksewerrat]

We also get a few DOT's that want an HL-93. Isn't that a bridge slab design?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[bridgebuster]

HS-25 is HS-20 +25%.

HL-93 is a bridge loading using the LRFD specs. It's an HS-20 truck + 640plf of uniform load spread over a 10' width. Whether you would apply the lane load in your situation is a matter of DOT policy. I designed some oddball drainage structures recently and we weren't required to use it. I would believe for a pipe under a road the lane load wouldn't be used.

 

[dicksewerrat]

Thanks again. Each DOT I deal with has a different idea for me.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[bridgebuster]

you're quite welcome.