Large fill alternatives 1

[Sox05]

What products are there that can be be used as fill for a large railroad project? The fills are as much as 30'. The soils are not good. The client needs to do this during the wet season. We are utilizing cement soil treatment, but it is proving to be expensive.

 

[civilperson]

What is not good about the soils that are available for borrow? Almost any soil with low organics can be made into a structural fill.

 

[Sox05]

The soil is mostly silt. the original geotech report was concerned that there would be significant settlement and shifting. another report says that the soil can be used for fill. I put the soil info in the question as FYI. If someone knows of something, but it requires strong soils to begin with, this is probably not a solution.

 

[civilperson]

Silt in a structural fill can be "strong soil". A specification of placing in 6" level lifts at 1% over optimum moisture with compactive effort to achieve 92-95% of a modified proctor will give a good fill with usable values of the magnitude you need.

 

[VAD]

The key here is wet season construction.

Lime is often used to aid the drying process. Usually 2 to 3 percent. With a fill height of 30 ft - not sure what the fill slopes are-, on ehas to be concerned about slope sloughs. On can try intermediate layers of gravel to aid in pore water presure dissipation of the fill is wet and no use of additives are required . Availability of granular material and cost comes in the picture as well. However,you noted that use of strong soils is not a solution.

The use of 6 inch fills while specified is hardly ever done or realistic. Try at least 500 mm lifts. The use of vibratory compactors and with hauling equipment, 95% Standard Proctor is readily achieveable these days. Getting closer to the top of the fill below the subballast, one my want to use non-woven fabric and better material for the top say 0.5m.

The above are not cast in stone and much depends on the nature of the fill. The term silt can also be a soil which has gravel sizes but has more silt sizes. It is often difficult without a gradation or look at the material, hence you are the judge. Look at the Proctor curve for moisture sensitivity of the material.

 

[Sox05]

Specs read 6'lifts
The client has on site borrow area
The cost is being driven up by using lime or cement used for soil stabilization because, of the time of year this work is going to happen.
I had hoped to investigate a product that could be placed while not being concerned with the rain. If the cost of the fill plus the cost of soil treatment was the same or more than placing another product, the client might consider it, just to make the schedule.

 

[civilperson]

Low weight foam block fills have been used to minimize consolidation/settlement of fills of great depth. Railroad loading is probably greater than highway loading so direct application needs analysis of the differences. Cost is quite low compared with imported fill, (not competitive with on-site borrow).

 

[Sox05]

Civilperson

Do you know where to look for a productline, a company a ....? I emailed the styrofoam industry and have not heard back. i even emailed the tire recycle assoc. i would like to come up with an alternative that is not so weather dependent.

 

[LCruiser]

"Specs read 6' lifts" - I presume you mean 6" lifts...

You are concerned with the substrate and not the fill material itself I would guess though. What, specifically, do the insitu materials show?

You can excavate and embed the foam material (some types are poured in place) for a completely neutral embankment.

 

[Sox05]

yes that was a typo it should have been 6"

i'm not really concerned with the material just the cost of the fill and placing the fill. i offered as a solution, not do the work for 3 months and pay the contractor accel. thinking that it might actually save money. That was not thought of highly. so then i figured find something that can be worked during the winter months, that would not be impacted as much by rain.

 

[eric1037]

You should probably consider traditional granular fill. If it is relatively clean sand, then it won't be nearly as difficult to use as the on-site silts.

If you want to investigate styrofoam backfill, check out this link:

http://www.geosynthetic-institute.org/products/gf.htm

However, the stuff is relatively expensive compared to traditional fill.

 

[civilperson]

Fifteen states have used "geofoam" fills including the Big Dig in Boston and I-15 in Utah. Two brands are Beaver Plastics, ("GeoFoam"), and FalconFoam, ("Geofoam"). In 24 inch thick blocks the volume cost is competitive with imported aggregates.

 

[LCruiser]

I wouldn't recommend something based on the Big Dig experience - especially in terms of cost effectiveness...

 

[civilperson]

LCruiser
Steel and concrete were both used in the Big Dig and I bet you are still using both materials in your designs.

 

[fattdad]

I'd consider placing the on-site soils and after reaching design grades, installing settlement plates to monitor for post-construction settlement.

f-d

¡papá gordo ain’t no madre flaca!

 

[jacare]

A small company called MineSeal, LLC mfgs and installs a polyurethane foam sealant to close hazardous mine openings and construction cavities. Their product is not in foam blocks, but rather, the material comes in portable boxes (1 cu yd) or in bulk (buckets & barrels). I know their material has been used by construction and mining companies & government agencies. The boxed materials are mixed manually in the field and the bulk material is applied mechanically. They have a website:

http://www.mine-seal.com