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SOIL CLASSIFICATION - Ms Ikmalzatul. CE 1203 : Geotechnical Properties and Construction Methods TWO KINDS of Soil...  Two kinds of soil in this world…

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Presentation on theme: "SOIL CLASSIFICATION - Ms Ikmalzatul. CE 1203 : Geotechnical Properties and Construction Methods TWO KINDS of Soil...  Two kinds of soil in this world…"— Presentation transcript:

1 SOIL CLASSIFICATION - Ms Ikmalzatul

2 CE 1203 : Geotechnical Properties and Construction Methods TWO KINDS of Soil...  Two kinds of soil in this world… COARSE FINE

3 CE 1203 : Geotechnical Properties and Construction Methods Fine-Grained vs. Coarse-Grained Soils U.S. Standard Sieve - No. 200  inches  mm

4 CE 1203 : Geotechnical Properties and Construction Methods Sieve Analysis ( Mechanical Analysis)  This procedure is suitable for coarse grained soils  e.g. No.10 sieve …. has 10 apertures per linear inch

5 CE 1203 : Geotechnical Properties and Construction Methods Hydrometer Analysis  Also called Sedimentation Analysis  Stoke’s Law

6 CE 1203 : Geotechnical Properties and Construction Methods Grain Size Distribution Curves

7 CE 1203 : Geotechnical Properties and Construction Methods Soil Plasticity Plasticity is a property that enables a soil to undergo deformation without breaking. Clays for instance are moulded into earthen pots when its plastic state. This property is characteristic on fined grained soils only, in the presence of water. When water is replaced by some other liquid, say kerosene, the clay will behave as a granular mass.

8 CE 1203 : Geotechnical Properties and Construction Methods Plasticity is due to clay minerals in the soils and is exhibited only over a specific range of moisture content. Excessive water turns the soil into a suspension (liquid state). With gradual decrease in the water content, the soil passes into a plastic state, then into a semi-solid (or semi-plastic) state and finally into a solid state.

9 CE 1203 : Geotechnical Properties and Construction Methods WA T ER CO NT EN T DE CR EA S IN G Liquid limit Plastic limit Shrinkage limit Solid SOLID STATE MOISTURE CONTENT SOLID STATE SEMI SOLID STATE PLASTIC STATE LIQUID STATE VOLUMEVOLUME Plastic state Semi-solid state

10 CE 1203 : Geotechnical Properties and Construction Methods The water content at which these changes of state occur called limits or indices. Albert Atterberg, Swedish Soil Scientist ( )…..series of tests for evaluating soil plasticity. He defined these limits as follows: the liquid limit (LL) is the water content at which a soil passes from liquid to plastic state; the plastic limit (PL) is the water content at which a soil passes from plastic to semi-solid state; and the shrinkage limit (SL) is the water content at which a soil passes from semi solid state.

11 CE 1203 : Geotechnical Properties and Construction Methods Further classification within fine- grained soils (i.e. soil that passes #200 sieve) is done based on soil plasticity. Arthur Casagrande adopted these tests for geotechnical engineering purposes

12 CE 1203 : Geotechnical Properties and Construction Methods  Consistency of fine-grained soil varies in proportion to the water content Atterberg Limits Shrinkage limit Plastic limit Liquid limit solid semi-solid plastic liquid Plasticity Index (cheese) (pea soup) (pea nut butter) (hard candy)

13 CE 1203 : Geotechnical Properties and Construction Methods Liquid Limit (LL or w L )  Empirical Definition  The moisture content at which a 2 mm-wide groove in a soil pat will close for a distance of 0.5 in when dropped 25 times in a standard brass cup falling 1 cm each time at a rate of 2 drops/sec in a standard liquid limit device

14 CE 1203 : Geotechnical Properties and Construction Methods Engineering Characterization of Soils Soil Properties that Control its Engineering Behavior Particle Size Particle/Grain Size Distribution Particle Shape Soil Plasticity fine-grainedcoarse-grained

15 CE 1203 : Geotechnical Properties and Construction Methods Clay Morphology Scanning Electron Microscope (SEM) Shows that clay particles consist of stacks of plate-like layers

16 CE 1203 : Geotechnical Properties and Construction Methods Soil Consistency Limits Albert Atterberg ( ) Swedish Soil Scientist ….. Developed series of tests for evaluating consistency limits of soil (1911) Arthur Casagrande ( ) …… Adopted these tests for geotechnical engineering purposes

17 CE 1203 : Geotechnical Properties and Construction Methods Arthur Casagrande ( ) Joined Karl Terzaghi at MIT in 1926 as his graduate student Research project funded by Bureau of Public Roads After completion of Ph.D at MIT Casagrande initiated Geotechnical Engineering Program at Harvard Soil Plasticity and Soil Classification (1932)

18 CE 1203 : Geotechnical Properties and Construction Methods Casagrande Apparatus

19 CE 1203 : Geotechnical Properties and Construction Methods Casagrande Apparatus

20 CE 1203 : Geotechnical Properties and Construction Methods Casagrande Apparatus

21 CE 1203 : Geotechnical Properties and Construction Methods Liquid Limit Determination

22 CE 1203 : Geotechnical Properties and Construction Methods  The moisture content at which a thread of soil just begins to crack and crumble when rolled to a diameter of 1/8 inches Plastic Limit (PL, w P )

23 CE 1203 : Geotechnical Properties and Construction Methods Plastic Limit (PL, w P )

24 CE 1203 : Geotechnical Properties and Construction Methods Plasticity Index ( PI, I P )  PI = LL – PL or I P =w L -w P Note: These are water contents, but the percentage sign is not typically shown.

25 CE 1203 : Geotechnical Properties and Construction Methods Plasticity Chart

26 CE 1203 : Geotechnical Properties and Construction Methods USCS Classification Chart

27 CE 1203 : Geotechnical Properties and Construction Methods USCS Classification Chart

28 CE 1203 : Geotechnical Properties and Construction Methods Plasticity Chart

29 THE END


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