Retaining Wall with Log Loader

[egc]

I have review duties for a bio-fuel project in GA. It has a ramp for Volvo log loaders to use (4 wheels, 50k each max load).

Ramp data:

Walls are 14" thick and extend 4' above travel surface to contain the loader(s).

Width: 35' (inside of walls)
Fill Height: 10'
Level Ramp Length: 35'
Sloping Ramp Length: 50'
Soil is Clean Structural Fill

The design engineer is using a 200 psf surcharge and has no barrier impact load included. What is the minimum design criteria that should be used (the AASHTO 250 psf seems low to me) and what about the barrier load from possible contact with a loader wheel?

 

[wmta]

I am not clear about a few things which could effect the surcharge loading to your wall. A surcharge of 250 psf/ft is a normal surcharge for heavy construction loading. But the actual loading of the loader may control. Normally i would expect so shoulder on the travel way and a width for barrier rail. Considering a wheel load 5 of 6 ft from the face of the wall is what i would normal expect. The lateral loading directly to the rail is an extra load that you may want to consider. I would consider ASSHO loading criteria for design of the barrier rail.

 

[Boondog]

Keep in mind the live load is an "equivilent" surcharge load. From what you provide, you have a 200,000 lb vehicle on the ramp. I would equate that load and see what you get. This sounds similar to loading used in mine operations. It may require a reinforced concrete slab to distribute the load and reduce the vertical stress on the wall. Was the designer provided with the 4x50k wheel loads? These load conditions are going to be outside the normal highway loads you typically see. An MSE wall may be a more cost effective alternative to this type of ramp.