Fire Truck Load 1

[ChipB]

I've always used the the worst moment and shear possible listed in the Civil Design book by Seelye (great book if you don't have it!)for my span when designing residential bridges.

i.e. Span=24';M=144 k*ft (H15); M=144.5 k*ft (HS15);
M=192 k*ft (H20); M=192.7 k*ft (HS20);
->use 192.7 for moment on bridge

My thoughts were, a concrete truck has to get across it to pour the footings and do any other concrete work, and, a firetruck must be able to pass over it.

I can't find anything in any of my reference books that states what highway loads these really would be classified as. I don't care if I am overdesigning, I just want to make sure I'm not under designing. Any suggestions or references?

 

[SlideRuleEra]

Take a look at American Association of State Highway & Transportation Officials (AASHTO) H-20 loading. It, and similar AASHTO loadings, are used to design highway bridges.
The H-20 loading is basically 36 kips per axle.

 

[ChipB]

Thanks, I forgot about that book since I'm only doing residential bridges stuff. I haven't looked at AASHTO's bridge specifications in a few years. (Since I took the exam) I'll have to dig it up and add it back to my library.

 

[whymrg]

According to

http://www.sutphen.com/

110' Platform Truck has
Weight = 73,500 lbs,
Wheel base = 252",
Front axle = 21,500 lbs,
Rear axle = 52,000 lbs'
Plus impact.

That's what we used ones for design of structure near fire station. Who knows what they may get in 5 years.

Good luck.

 

[Ron]

Check the axle loads on some of the tankers. They get quite high. There was another thread along these lines some time back. Do a keyword search...you might find additional inf.