procedures for foundations on fills
procedures for foundations on fills
(OP)
I like to know the procedures to make foundations on filled
soil. How to determine the bearing capacity and other soil parameters for the design of foundation.
soil. How to determine the bearing capacity and other soil parameters for the design of foundation.





RE: procedures for foundations on fills
Considerations When Building on Landfills
Prepared by:
Tom MacDougall
In general, poorly consolidated fills have a significant time component to its behaviour. Floating foundations (with the need to equilibrate weights and uplift) may be convenient.
More frequently and if feasible, deep foundations are better. Always consider then the further settlement of the fill loading through friction the piles.
Intercalation of permanent jacks may help to keep the main structure as intended upon variable settlements, but this is not be going nor cheap nor it is very clear how to adapt ordinary structures and foundations to these contraptions.
Don't forget to check a pair of books on foundations.
RE: procedures for foundations on fills
In general, the issues are:
1) Make sure the fill was placed over competent material (this is done by a geotechnical investigation)
2) Determine the character and properties of the fill (lab testing for classification, in-place density testing for compaction, plate bearing tests if appropriate for indications of bearing capacity)
3) Evaluate these concurrently with respect to your building loads
RE: procedures for foundations on fills
If the soil is cohesive, samples should undergo an unconfined compression strength test. From the unconfined compression strength the bearing capacity can be calculated.
If the fill soil was not placed under field control, it should not be used to support structure foundations without first taking soil borings and performing tests (as recommended by Ron above) to determine the allowable bearing capacity.
RE: procedures for foundations on fills
For cohesionless soils, settlement is in the main immediate while for cohesive soils, the consolidation characteristics will provide a guide for the determination of the settlement monitoring program - long term settlement.
A note of caution though, soil science is not an exact science. Theory always gives conservative results.
For a fill, settlement results from both the fill material (duration dependent on fill material), depth/thickness of fill, thickness and depth of underlying clay layer - from a sub soil investigation survey.
The choice of foundation type will depend on the type of facility proposed and loads in service.
NB Hydraulically placed, well graded granular fills can support light structures - for which a pad foundation may be proposed. For critical facilities however, for which settlement is a key consideration, then a pile foundation is the answer. Even for piles, ongoing settlement gives rise to negative skin friction.
Frequently though, it is often the practice that fill grounds serve only to provide a working platform subjected to minimum service loads - roads, walkways etc.
kay
RE: procedures for foundations on fills
RE: procedures for foundations on fills
To consturct the foundation on fill it has been always a
challenge..... but one can constuct a safe structure on it.
my filling is that first of all you should do some SPT test and get the idia of bearing capacity of soil ... second generally in fill material some oxidizing materials will always be present so it makes the water, acidic, presented in soil mass... which can destorts the foundation material. to design the foundation is as usual.. what procedure is following as a standard. but you should always consider secondary consolidation while designing. also if you are going to place precast pile so my suggestion is that use epoxy coating on plies before installing.
i think i gave reply from my best level.
byebye friend
RE: procedures for foundations on fills
RE: procedures for foundations on fills
Cheers
RE: procedures for foundations on fills
RE: procedures for foundations on fills
Regarding collapse potential... We have only seen it in granular soils. And, the collapse potential test (ASTM D5333) has shown that at whatever moisture content 95% of D1557 is achieved, the collapse potential is slight.