LAB MANUAL 3SieveAnalysis

# LAB MANUAL 3SieveAnalysis - CIVE 310 Soil Mechanics Sieve...

This preview shows pages 1–4. Sign up to view the full content.

22 CIVE 310 Soil Mechanics Sieve Analysis Section Assigned Due Monday Before Lab: Read this Handout

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
23 SIEVE ANALYSIS Grain Size Analysis In order to classify a soil for engineering purposes, one needs to know the distribution of the size of grains in a given soil mass. There are 3 methods used to determine the grain size distribution of soils. 1) Sieve analysis - for soils consisting primarily of particles > 0.074 mm (soils with grain sizes mostly > #200 sieve) 2) Hydrometer analysis - for soils consisting primarily of particles < 0.074 mm (soils with grain sizes mostly < #200 sieve) 3) Combined analysis - perform both sieve and hydrometer analysis on mixed soils Why do we need to do a grain size analysis? 1) For basic information - needed for soil classification 2) For quality assurance in: a) aggregate production plants b) for fill materials c) for sand filters d) for concrete production A grain size distribution is a statistical distribution. Quantities of the same sizes found in a random lab soil sample will generally be found in the field. The American Society for Testing and Materials specifies standard procedures for tests. ASTM D 422 is the test specification number for the grain size distribution tests. Specification ASTM D 421 provides the standard practices for the dry preparation of soil samples. A random sample can be selected by quartering or splitting (Figure 1). Sieving the Sample 1) Hand Sieving a) could use wire-mesh screens placed in frames b) usually use very large opening sizes down to about 25 &m in size
24 c) could also use standard 8"-diameter, 2"-deep sieves which are portable and easily used by hand 2) Mechanical Sieving a) use a Ro- Tap machine with a stack of sieves (Figure 2) b) seven sieves and a pan at the bottom (Figure 3) What do we do with the data we obtain? The results of mechanical analyses are generally presented on semilogarithmic plots known as particle-size distribution curves . From these curves we can determine 3 basic soil parameters: 1) The effective particle sizes (i.e. - D 10 = 10% finer diameter) 2) The Coefficient of Uniformity 3) The Coefficient of Curvature (or Gradation) A construction of these calculations can be found in Example 1. Coefficient of Uniformity

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/03/2008 for the course CIVE 310 taught by Professor Iforget during the Spring '08 term at Drexel.

### Page1 / 14

LAB MANUAL 3SieveAnalysis - CIVE 310 Soil Mechanics Sieve...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online