Foundation on FIlled up soil

[Balageotech]

Dear Experts!!!

I have a situation,

The project land is 4.0m lower than Road level, and the Hard rock is exist at 3.0m below existing ground level.

As the land is low lying, the project team decided to fill-up the land around 4.0 to 4.5m with engineering fill to match the road level.

As this is industrial plant, the Maximum column load expected to be in the range of 400 to 500 tons.

Can I rest my foundation on filled up soil(engineering fill) if I can achieve 99% Modified proctor density compaction?

Regards
Bala

 

[hokie66]

You need to obtain this advice from a geotechnical engineer in your area. Factors involved include the subgrade as well as the fill material. Settlement of the fill material as well as the subgrade need to be evaluated, and compaction of the fill is only one parameter in that evaluation.

 

[SuperSandman]

I agree with hokie66.

The fill can be designed to exhibit low settlement. What soils do the insitu subgrade comprise of?

 

[Balageotech]

This is Uniformly graded .

 

[fattdad]

yes.

f-d

ípapß gordo ainÆt no madre flaca!

 

[BigH]

Personally, I would have filled up a bit above the road level - say 500 mm to 1000 mm. Engineered fill can be of many types of materials and it would be nice to know exactly what the fill materials are made of and the underlying strata, i.e., the soil above the "hard rock". Once the fill was/is in place, I would do a site investigation to determine the properties (strength and settlement) - not just that it has been placed to 99% modified Proctor - unless of course you have run undrained triaxial tests and consolidation tests if the fill material is clayey/silty in nature. If the engineered fill was crushed sand and gravel (like we would have in Ontario), then placed to that compaction, I would safely assume 350 kPa allowable bearing (but you would have to be comfortable with it) subject to suitable underlying soil above the hard rock. if the fill is sand (such as river sand), I would do some site investigation works to get the properties you need.

 

[Balageotech]

Thank you all for your valuable time and Suggestions...

 

[cvg]

why not relax your compaction requirements a bit and just use piles to the shallow bedrock layer. might be cheaper than a mat or spread footings

 

[Balageotech]

Yes.. I understand that part too. Let me check it out the options..

Thanks

 

[Ron]

Yes...if the fill is granular and placed in layers of 300mm to 500mm and each layer is compacted to the level you noted.

Expect elastic settlement of the foundation; however.

 

[Mercycity]

I am suggesting that instead of filling to road level, take advantage of rock at 3m, use piles to support the building and that 4m height your planning to fill, why not change the design to be a basement for parking or for storage. In such a way you will be relax in your calculation and the buildings will have more space. That is my advice.