Fixing Road and Pad Built on Loam Soil

[mechanicalchad]

I have inherited a site that has a gravel road and pad built over a layer of loam top soil. The area is prone to being muddy after very short rainfalls, and I have been looking at options to improve this. This problem is compounded by the previous thought that adding more gravel would fix the muddiness problem and so I have about 2 feet of gravel overtop of a 12" loam layer. There is also very little drainage. Aggregate that was put down was a 3/4" crush.

I'm looking for ideas on what is the most cost effective way of fixing this problem. I think I probably have to strip the aggregate back, remove the loam, and grade and pack the clay with a good cross slope, and then put the aggregate back. I'm guessing the aggregate probably has loam mixed in with it now, and so I'm wondering of ways that I can still use this aggregate, maybe clean it up somehow. 2 feet is a lot of aggregate (in some cases its even more), and so I would like to re-use if possible.

If I can re-use it, I would like to put a geotextile and geogrid down, and only use 12" of aggregate so I can double the size of my pad. If I build more pad though, I don't want to use poor quality gravel and extend my problem into new areas.

Any ideas are very appreciated.

Thanks,
Chad

 

[oldestguy]

First things first. What is your climate? Equatorial? Sub-Artic? What is the road used for? Is it one lane or more? What kind of traffic. autos only? Maybe a truck or two daily and how heavy? What is the lay of the ground, flat, swampy, hilly with rock exposed? Do you have an idea where the ground water table might be as to depth below ground surface? To clarify, what is your definition of "loam"? Geotechnically speaking loam generally means a mix of fine sand, silt and clay. However, technically we avoid the use of that word, due to so many possible meanings. Some areas call dark organic topsoil Loam. What do you mean by "pad" specifically (concrete slab x inches thick?), carrying what load?. What is happening to your gravel layer? How was it placed, trucks driving backwards dumping as they went? etc? Spread by what? do you have access to what road construction equipment or a contractor with a good variety of equipment? What trade name geogrid and weight are you thinking of? Is there a source of Portland cement in the area? The more you can say about this, the easier and better the replies.