1. Faculty of Applied Engineering and Urban Planning Civil Engineering Department Soil Mechanics ECGD3303 Grain Size Analysis Lecture 2 Week 1 1 st Quadester 2007/2008 UP Copyrights 2007

2. Content Purposes of Grain Size Analysis Sieve Analysis Hydrometer Analysis Particle Distribution Shape of Soil Particles

3. Purposes of Grain Size Analysis The size distribution is often of critical importance to the way the material performs in use. Concrete StructuresEconomical Filler Examples Roads ConstructionBearing Base AgricultureInfiltration Rate EnvironmentFilters

5. Grain Size Analysis S 1 < d M 1 % S 3 < d < S 2 M 3 % S 2 < d < S 1 M 2 % d < S 3 M 4 %

6. Sieve Analysis

8. Standard Sieves Sieve Opening (mm) Sieve No. 4.7504 2.00010 0.85020 0.42540 0.25060 0.150100 0.075200 See text book (table 2.5)

9. Cohesiveness Soils can also be divided into: cohesive and non-cohesive Non-cohesive means the soil has no shear strength if no confinement. Cohesive soil contains clay minerals and posses plasticity Clay is cohesive and plastic. Sand is non-cohesive and non-plastic.

10. Hydrometer Analysis Based on the principle of sedimentation of soil grains in water and bouncy principle. Stock’s Law V1V1 V2V2 < Bouncy Force F = V ρ g

11. Hydrometer Analysis

12. Questions?! 30:00 min

13. Percent Finer 76.2 mm 4.75 mm 0.075 mm Pan 100 % Finer (Passing) 93 % 62 % 0 % Gravel Sand Silt and Clay 100 – 93 = 7% 93 – 62 = 31% 62 – 0 = 62% Gravel Sand Silt and Clay

14. Example: Sieve Analysis

17. Log-Scale

18. Group Work

19. Particle-Size Distribution Curve

20. 1. Effective Size (D 10 ) 2. Uniformity Coefficient (C u ) 3. Coefficient of Gradation (C z ) 10% FinerHydraulic Conductivity

21. Particle-Size Distribution Curve 1. Effective Size (D 10 ) 2. Uniformity Coefficient (C u ) 3. Coefficient of Gradation (C z ) 10% FinerHydraulic Conductivity

22. Particle-Size Distribution Curve Question What is the C u for a soil with only one grain size?

23. Particle-Size Distribution Curve Uniformity Coefficient (C u ) D Finer Grain size distribution

24. Particle-Size Distribution Curve Criteria for Well-Graded Soil

25. Particle-Size Distribution Curve

26. Questions?! 90:00 min

27. Hydrometer Analysis Stokes’ Law

28. Hydrometer Analysis

29. R L L = 16.29 – 0.164 R

30. 1. Temperature (F T ) 2. Meniscus Correction (F m ) 3. Zero Correction (F z ) F T = - 4.85 + 0.25 T Corrections: Hydrometer Analysis

31. Questions?! 105:00 min

32. Example: Sieve Analysis

33. Rounded Angular

34. Questions?! 120:00 min