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Foundation Sinking

07/05/2010 3:36 AM

In one of the factory building under construction the machinery Foundation sunk by 7-8Mm.The consultant and Contractor blame each other.An external consultant who took a sizable fee was not of much help.The theory advocated by the external consultant is water from a pond nearly 700M has seeped through and caused the sinking.Though I am an electrical engineer ,I find it difficult to swallow this theory,The reason I feel could be poor compacting. There are other foundations which remain unaffected.How do we check the entire thing and what is the best method to rectify.

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Anonymous Poster
#1

Re: Foundation Sinking

07/05/2010 11:20 PM

It looks like your consultant and external consultant are shortchanging you. with out knowing the soil condition and soil chemistery its foolish to design foundations it seems form your statement they have assumed the soil conditions and chemistery with out conducting or asking for the tests.

crm

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#2

Re: Foundation Sinking

07/05/2010 11:48 PM

The most effective solution is to hire a concrete leveling company who will bore down through your foundation and pressure pump what is effectively a grout mix that will further compact your existing sub-grade, then- after the "final compaction is completed- it will raise your foundation to its "correct" level.

The advantage is that the grout mix does compact your existing sub-grade the way it should have been done to start.

After you solve your problem, have the ORIGINAL consultant show you their records of the ground test that was done at THAT location and review the specifications to see what level of compaction they specified. If they have not records, or did not specify a defined level of compaction, they pay for the pumped grout repair (and the second consultant).

If they have the records to show that they did their job at the start, then go to the contractor and have them produce the records of the compaction test they performed to verify that that ground was packed to spec. Again, if they have no records, they pay for the repair (and the second consultant).

If everyone has their ducks in a row, then the second consultant might be right so you are stuck with a fluke of nature, but at least the foundation should have no more problems because of the pressure lift.

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#4
In reply to #2

Re: Foundation Sinking

07/06/2010 1:08 PM

Thanks a lot Energygod.Each one of them had maintained record but all cooked up.I think the best solution is what u have stated.Some have suggested sand piling.What's your view?Also how do we check other foundations that are near by but have not yet sunk.

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#5
In reply to #4

Re: Foundation Sinking

07/06/2010 2:05 PM

My experience with the "grout" injection has been very positive. No experience with sand.

Regarding other foundations- if they have not sunk NOW, they are likely OK. You could try some artificial loading with whatever "heavy" stuff you might have around, but that fact that the problem foundation sank when all others did not suggests a site specific issue.

Hope all works out well.

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#3

Re: Foundation Sinking

07/06/2010 6:25 AM

enerygod answered the question. "sandjacking & mudjacking which is better for your situation?

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Anonymous Poster
#6

Re: Foundation Sinking

07/09/2010 10:14 AM

Hi,from construction point of view,soil investigations was to be done before strat of construction,soil bearing,organics contents,underground conditions like burrongs,cavities etc,etc..earth tremmors etc,etc ..etc..but again it can be a reason for soil sinking from a cause of severe moisture variations like introduction of deep/shallow wells from the nearby vicities,nearby introductions of dams(ponds) which alters soils moistures in high magnitudes(increase of moisture facilitates soil particles lubrications hence lowering shear forces of the soils, etc)... so still I cant go much against second consultants conclusions if at all all soil tests undertaking were done before construction...bearing into mind that internal water flows can be triggered after disturbance of soils as it happens during construction plus machines vibrations(mixers etc)...and if is so,then there is nobody exactly to blame!! it should be a mutual responsibility on the issue!!!

Arold Tanzania..

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#7

Re: Foundation Sinking

07/10/2010 7:31 AM

Thanks a lot to all of u. regards

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