This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 30 02 Phases of Soils Relationships *01. Convert from metric units to SI and US units. *02. Compaction checked via the voids ratio. *03. Find the moisture w when the soil is fully saturated. *04. Identify the wrong moisture data. *05. Dry unit weight and degree of saturation. *06. Increasing the saturation of a soil. *07. How much water is required to add to a truck due to evaporation? *08. Find & d , n , S and W w . *09 Use the block diagram to find the degree of saturation. *10. Use the block diagram by setting the solids volume V s to 1 m 3 . *11. Use the block diagram by setting the total volume V to 1 m 3 . *12. Use the block diagram to find the dry weight of a saturated soil. *13. Find the weight of water needed to attain saturation. *14. Identify the wrong piece of data. *15. The apparent cheapest soil is not! *16. How many truckloads for the dam project? *17. How many truckloads are needed for a housing project? **18. Choose the cheapest fill supplier. **19. Use a matrix to find the missing data. **20. Find the voids ratio of “muck” (a highly organic soil). Symbols for the Phases of Soils e & Voids ratio. G S & Specific gravity of the solids of a soil. n & Porosity. S & Degree of saturation. V & Total volume (solids + water + air). V a & Volume of air. V V & Volume of voids (water + air). V S & Volume of solids. V W & Volume of water. w & Water content (also known as the moisture content). W S & Weight of solids. W W & Weight of water. ¡& Unit weight of the soil. ¡ d & Dry unit weight of the soil. ¡ b & Buoyant unit weight of the soil (same as ¡ ’ = ¡ sat ¡ w ). ¡ SAT & Unit weight of a saturated soil. ¡ W & Unit weight of water. 31 Basic Concepts and Formulas for the Phases of Soils. (A) Volu metri c Relat ions hips: 1.  Voids ratio e V S V e V = range s from 0 to infinity. Typical values of sands are: very dense 0.4 to very loose 1.0 Typical values for clays are: firm 0.3 to very soft 1.5. 2 .  Porosity n ( ) 100% V V n V = ranges from 0% to 100%. The porosity provides a measure of the permeability of a soil. The interrelationship of the voids ratio and porosity are given by, 32 1 1 n e e and n n e = = + 3.  Saturation S 100% W V V S x V = ranges from 0% to 100%. (B) Weight Relationships: 4.  Water content w 100% W S W w x W = Values range from 0% to over 500%; also known as moisture content . 5. – Unit weight of a soil & S W S W A W W W V V V V γ + = = + + The unit weight may range from being dry to being saturated. Some engineers use “ bulk density ¡ ” to refer to the ratio of mass of the solids and water contained in a unit volume (in Mg / m 3 ). Note that, . W m g g which is the equivalent of F ma V V γ ρ = = = = 6.  Dry unit weight & d 1 S d W V w γ γ = = + The soil is perfectly dry (its moisture is zero). 33 7.  The unit weight of water & w 3 ( ) 62.4 1 / 1 / 9.81 / W w W w W where g F ma V pcf g ml kg liter kN m γ γ ρ γ = = = = = = = Note that the above is for fresh water. Salt water is 64 pcf, etc. Note that the above is for fresh water....
View
Full Document
 Summer '10
 STAFF
 unit weight, vw

Click to edit the document details