Soil Properties

• Oct 18, 2013

• #2

Ron

Structural

Sep 24, 1999

16,336

US

Basic geotechnical engineering....influence of the footing is usually taken to a depth of 2B, with "B" being the footing width, and the influence taken at a 45 deg line from the footing edge downward.

 

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• Oct 19, 2013

• #3

BigH

Geotechnical

Dec 1, 2002

6,012

TJ

I certainly, though, wouldn't dig out a couple of footing widths just to put in compacted engineered fill - unless it was required due to the natural ground not being suitable.

 

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• Nov 20, 2013

• #4

dBasement

Geotechnical

Mar 18, 2008

37

CA

Absolutely you would. If the soil underlying the proposed foundation has insufficient strength or bearing properties that deems it unacceptable for supporting the foundation, it needs to be dug out and replaced with structural fill, that means you dig out as well as down (per above).

 

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• Nov 21, 2013

• #5

BigH

Geotechnical

Dec 1, 2002

6,012

TJ

I hope that dBasement understood that I would not dig out good bearing soil just to put it on engineered fill. Of course, if the soil is poor, one could remove and replace. 2x might not be large enough for strip footings that normally have pressure bulbs to depths of 3.5 to 4x footing width. One might consider the use of digging out partially and using geogrids (see paper by Braja Das and Adel Hanna on Model tests for shallow strip foundation on granular soil in ASCE Special Publication No. 16, Special Topics in Foundations (1988).

 

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