Quickest way to check road base material follwoing rain event
Quickest way to check road base material follwoing rain event
(OP)
Guys
Good Morning. We are working on access roads for a wind project in Oklahoma. The contractor is using a different material than the one specified in spec. Following a rain event, the road surface looks muddy and slush. Is there a quickest way to check road base material like pocket penetrometer for soil to assess the quality of the road base material?
Your suggestions are highly appreciated
Thanks
NT
Good Morning. We are working on access roads for a wind project in Oklahoma. The contractor is using a different material than the one specified in spec. Following a rain event, the road surface looks muddy and slush. Is there a quickest way to check road base material like pocket penetrometer for soil to assess the quality of the road base material?
Your suggestions are highly appreciated
Thanks
NT





RE: Quickest way to check road base material follwoing rain event
RE: Quickest way to check road base material follwoing rain event
RE: Quickest way to check road base material follwoing rain event
Thanks for the input, the road is to be used as an access road for a wind project for turbine deliveries and site construction during the construction of the wind project. During construction the traffic will be heavy with the concrete trucks moving and other wind turbine carrying trucks and construction traffic. later it is to be used only for access.
Based on your experience is there a quick way (like we measure the shear strength of clay using pocket penetrometer), is there a quick check that we can make for the aggregate material.
Thanks
NT
RE: Quickest way to check road base material follwoing rain event
In your case, you may have some weaker subgrade places where a greater thickness may be needed. I'd also be prepared to add base where I see the traffic is deflecting too much and there may be bad rutting.
You may even decide to undercut obviously bad areas and replace that thickness with base, adding above that the "design' thickness base.
If there is going to be a lot of repetitive heavy traffic, you may decide to go a little thicker than the "test" area "design". Repeated loads on some areas (usually silty soils, saturated) will cause a build up of pore pressures, leaving a much weaker subgrade result. Wait until the next day and all is OK, until repeated loads come again.
In some cases the added "repair" base material is a much coarser breaker-run quarry rock to soak up the softer base material.
Before doing the test, see if you can just add a layer of that coarser material to see if that thickness can be used to salvage what yu now have, instead of more of the same (failed base type).
One one job I was on the coarser stuff was reject bricks from a brick yard. However, that got stuck between the duals of the trucks.
Be sure the base roadway is sufficiently wide that shear failures off to the side don't occur.
RE: Quickest way to check road base material follwoing rain event
Oldestguy has good discussion on what you can do - forgetting the contractual arrangements. Without knowing your subgrade, the basecourse material and the like it is not possible to really offer more than general commentary. You could do a benkelman beam test - which is a deflection test - to determine the road base's behaviour under loading and then "top up" with extra granular - but the driving of heavy trucks looking for rutting might be more expedient.
Did you think of adding a geogrid? this might be possible if the road is not behaving good under its current thickness (and this leads back to why the contractor is using non-compliant material). I would consider adding if you will top up with granular.
Is the road going to be used permanently?
RE: Quickest way to check road base material follwoing rain event
RE: Quickest way to check road base material follwoing rain event
RE: Quickest way to check road base material follwoing rain event
I really appreciate your feedback on this issue. This gives me some insight. Another question I had is that the contractor is proposing to use 4" road base material (based on the anticipated traffic volume) and the rut depth considered is 3" as per AASHTO design methodology. Do you think considering 3" rut depth makes sense. What is the practical rut depth considered for soils in Oklahoma Panhandle ? or in general.
if 3" rut depth is normal, what happens to the road with a base material of 4", there is only 1" material left after rut.
Thanks
NT
RE: Quickest way to check road base material follwoing rain event
Richard A. Cornelius, P.E.
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