Soil Phase Relations (Void Ratio, Porosity, Saturation)
The three-phase makeup behind every settlement and bearing calc, made explicit: from the total unit weight, water content, and specific gravity Gs, the dry unit weight gamma_d = gamma/(1 + w), void ratio e = Gs gamma_w/gamma_d - 1, porosity n = e/(1 + e), and saturation S = w Gs/e. A 120 pcf soil at 15% and Gs 2.70 gives gamma_d 104.3 pcf, e 0.62, n 0.38, S 66% - the void ratio a consolidation needs, the saturation that says how much air is left to squeeze out. gamma_w = 62.4 pcf; enter Gs. An engineering aid; the soil test data govern.
Formula and source
gamma_d = gamma/(1 + w/100); e = Gs gamma_w/gamma_d - 1; n = e/(1 + e); S = w Gs/e. (gamma_w = 62.4 pcf)
The soil three-phase relations - dry unit weight, void ratio, porosity, and degree of saturation - as compiled in the Das and NAVFAC geotechnical references, by name.
Audience
This tile is built for trades and the adjacent professions in the Carpentry and Construction group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
Related tools
Posture
Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.