The document discusses soil phases and their relationships. Soils can exist in two or three phases depending on their water content. A dry soil contains solid particles and air, while a saturated soil contains solid particles and water. A partially saturated soil contains solids, water, and air. The key soil properties discussed are void ratio, porosity, water content, degree of saturation, specific gravity, and unit weight, and their relationships are explained through equations and examples.
The document discusses soil phases and their relationships. Soils can exist in two or three phases depending on their water content. A dry soil contains solid particles and air, while a saturated soil contains solid particles and water. A partially saturated soil contains solids, water, and air. The key soil properties discussed are void ratio, porosity, water content, degree of saturation, specific gravity, and unit weight, and their relationships are explained through equations and examples.
The document discusses soil phases and their relationships. Soils can exist in two or three phases depending on their water content. A dry soil contains solid particles and air, while a saturated soil contains solid particles and water. A partially saturated soil contains solids, water, and air. The key soil properties discussed are void ratio, porosity, water content, degree of saturation, specific gravity, and unit weight, and their relationships are explained through equations and examples.
The document discusses soil phases and their relationships. Soils can exist in two or three phases depending on their water content. A dry soil contains solid particles and air, while a saturated soil contains solid particles and water. A partially saturated soil contains solids, water, and air. The key soil properties discussed are void ratio, porosity, water content, degree of saturation, specific gravity, and unit weight, and their relationships are explained through equations and examples.
Download as PPTX, PDF, TXT or read online from Scribd
Download as pptx, pdf, or txt
You are on page 1/ 30
SOIL PHASE
Soil Composition & Phase
• Soil Composition: – Solids – Water – Air
• Soil Phases: – Dry – Saturated – * Fully Saturated – * Partially Saturated – Submerged SOIL PHASE RELATIONSHIPS Soils can be of either two-phase or three-phase composition. In a completely dry soil there are two phases, namely the solid soil particles and pore air. A fully saturated soil is also two phase, being composed of solid soil particles and pore water. A partially saturated soil is three phase, being composed of solid soil particles, pore water and pore air. Soil Phase
Weight Wt = Ww + Ws Volume Vt = Vv + Vs = Va + Vw + Vs Soil Volume Soil Weight
Wa ≈ 0, equal : T T VOLUME RELATIONSHIP 1. Void ratio = e 0<e<~
0≤n≤1
2. porosity = n (%)
3. e & n WEIGHT & VOLUME RELATIONSHIP
4. Water content= w 0< w<~
5. Degree of Saturation = S 0<S<100%
6. Spesific Gravity = Gs 7. Unit Weight = g RELATION of g ; e ; w ; Gs 1. Spesific Gravity (Gs)
V s = 1,then gs = Ws
Ww = w x Ws Ww = w x Gs x gw
if Ww = w x Gs x gw Then
Vw = w x Gs
V s = 1, then so
2. Unit Weight of Soil (g) 3. Unit Weight of Dry Soil (gd)
Typical Values of Specific Gravity
(Lambe and Whitman, 1979)
(Goodman, 1989) 4. Degree of Saturation (SR)
5. Unit Weight of Saturated Soil (g ) SAT
In a saturated condition, SR =1 (100%)
Relation Between g ; n ; and w To make the relation between g , n dan w , we use the assumption that VT (volume total) = 1
V T = 1, then
Ws and Ww can be defined as:
4. Degree of Saturation (SR)
5. Unit Weight of Saturated Soil (g ) SAT
In a saturated condition, SR =1 (100%)
Relation Between g ; n ; and w To make the relation between g , n dan w , we use the assumption that VT (volume total) = 1
V T = 1, then
Ws and Ww can be defined as:
• In which
We know that:
Then
In saturated condition: Where And so the Degree of Saturation can be defined as: Example 1:
•In its natural state, a moist soil has a total volume of 9344.56 cm3 and a mass 18.11 kg. The oven-dry mass of soil is 15.67 kg. If Gs = 2.67, calculate the moisture content Example 2
Method 1a Example 2
Method 1a Method 1b Method 2: Given : w = 9.8% , g = 19.2 kN/m3, Gs = 2.69 required: gd , e, n, S
V 0.01931 Vw 0.00998 e= V = = 0.51 kN/m 3 S= = 100 = 51.68% VS 0.03789 Vv 0.01931 Example 3 • Field density testing (e.g., sand replacement method) has shown bulk density of a compacted road base to be 2.06 t/m3 with a water content of 11.6%. Specific gravity of the soil grains is 2.69. Calculate the dry density, porosity, void ratio and degree of saturation. Relative Density The relative density is the parameter that compare the volume reduction achieved from compaction to the maximum possible volume reduction The relative density Dr, also called density index is commonly used to indicate the IN SITU denseness or looseness of granular soil.
Volume reduction from compaction of granular soil
Dr can be expressed either in terms of void ratios or dry densities.
28 Remarks
The relative density of a natural soil very strongly affect its
engineering behavior.
The range of values of Dr may vary from a minimum of zero for
very LOOSE soil to a maximum of 100% for a very DENSE soil.
Because of the irregular size and shape of granular particles, it is
not possible to obtain a ZERO volume of voids. (Do you remember well-graded vs. poorly-graded!!)
ASTM test designations D-4253 and D-4254 (2007) provide
procedure for determining maximum and minimum dry unit weights of granular soils. Granular soils are qualitatively described according to their relative densities as shown below
The use of relative density has been restricted to granular soils
because of the difficulty of determining emax in clayey soils. Liquidity Index in fine-grained soils is of similar use as Dr in granular soils.
Greenbacks From Green Roofs: Forging A New Industry in Canada Status Report On Benefits, Barriers and Opportunities For Green Roof and Vertical Garden Technology Diffusion
Greenbacks From Green Roofs: Forging A New Industry in Canada Status Report On Benefits, Barriers and Opportunities For Green Roof and Vertical Garden Technology Diffusion
