Soil Mechanic
2/26/2013
SOIL MECHANICS 1 KAEA 2132 - Phase diagram & phase relationship -
Soil-Aggregate Basic Relationship
Dr. Meldi Suhatril
Department of Civil Engineering, Faculty of Engineering, University of Malaya.
Review : o Soil is inherently multiphase material
(Generally consists of three phases)
i. Solid phase ii. Liquid phase iii. Gaseous phase
3 – Phase system:
AIR WATER
Vv
Va Vw Vs
Wa= 0 Ww Ws
=
o It can also be TWO PHASE material
i. With solid + Gaseous (DRY STATE) ii. With solid + Liquid (SATURATED STATE)
SOLIDS
V = Vs + Vw + Va
W = Ws + Ww + Wa
Partially Saturated Soil
1
2/26/2013
2 – Phase system:
AIR WATER
Volumetric ratios
Vv=Vw
Vv=Va
Wa
Ww W Ws
Volumetric ratios commonly used in soil mechanics are:
i. Void ratio,
V
Vs
SOLIDS
Ws Vs
SOLIDS
e
ii. Porosity, n iii. Degree of Saturation, Sr iv. Air Content, ac v. Air void ratio or Percentage air voids, na
Dry soil
Saturated soil
Void ratio e is defined as the ratio of volume of voids to the volume of solids
e=0 e>1
absence of voids (solid material) Vv >> Vs in the soil mass
e = Vv /Vs
• Volume of voids Vv refers to that portion of the volume of the soil not occupied by solid grains Since the relationship between Volume of air Va and Volume of water Vw usually changes with ground water conditions as well as imposed loads, it is convenient to designate all the volume not occupied by solid grains as void space Volume of voids Vv
•
Soil type Void ratio e Uniform sand, loose Mixed-grain sand, 0.85 dense 0.43 Soft glacial clay 1.20 Soft highly organic 3.00 clay 5.20 Soft Bentonite
2
2/26/2013
• In nature, even though the individual void spaces are larger in coarse-grained soils, the void ratios of fine-grained soils are generally higher that those of coarse-grained soils. The ratios of volume of voids Vv to total volume V is defined as Porosity n.
• Porosity n of soil cannot exceed 100% 0 <
SOIL MECHANICS 1 KAEA 2132 - Phase diagram & phase relationship -
Soil-Aggregate Basic Relationship
Dr. Meldi Suhatril
Department of Civil Engineering, Faculty of Engineering, University of Malaya.
Review : o Soil is inherently multiphase material
(Generally consists of three phases)
i. Solid phase ii. Liquid phase iii. Gaseous phase
3 – Phase system:
AIR WATER
Vv
Va Vw Vs
Wa= 0 Ww Ws
=
o It can also be TWO PHASE material
i. With solid + Gaseous (DRY STATE) ii. With solid + Liquid (SATURATED STATE)
SOLIDS
V = Vs + Vw + Va
W = Ws + Ww + Wa
Partially Saturated Soil
1
2/26/2013
2 – Phase system:
AIR WATER
Volumetric ratios
Vv=Vw
Vv=Va
Wa
Ww W Ws
Volumetric ratios commonly used in soil mechanics are:
i. Void ratio,
V
Vs
SOLIDS
Ws Vs
SOLIDS
e
ii. Porosity, n iii. Degree of Saturation, Sr iv. Air Content, ac v. Air void ratio or Percentage air voids, na
Dry soil
Saturated soil
Void ratio e is defined as the ratio of volume of voids to the volume of solids
e=0 e>1
absence of voids (solid material) Vv >> Vs in the soil mass
e = Vv /Vs
• Volume of voids Vv refers to that portion of the volume of the soil not occupied by solid grains Since the relationship between Volume of air Va and Volume of water Vw usually changes with ground water conditions as well as imposed loads, it is convenient to designate all the volume not occupied by solid grains as void space Volume of voids Vv
•
Soil type Void ratio e Uniform sand, loose Mixed-grain sand, 0.85 dense 0.43 Soft glacial clay 1.20 Soft highly organic 3.00 clay 5.20 Soft Bentonite
2
2/26/2013
• In nature, even though the individual void spaces are larger in coarse-grained soils, the void ratios of fine-grained soils are generally higher that those of coarse-grained soils. The ratios of volume of voids Vv to total volume V is defined as Porosity n.
• Porosity n of soil cannot exceed 100% 0 <