2021-04-16

## What does the term well graded mean in regards to grain size distribution?

A well graded soil is a soil that contains particles of a wide range of sizes and has a good representation of all sizes from the No. 4 to No. 200 sieves. A well graded gravel is classified as GW while a well graded sand is classified as SW.

What is meant by a well graded curve in sieve analysis?

Well means good and gradation means distribution of particles. That is good distribution of particles that says, all the particles of different sizes are present in this soil. Hence this curve is said to be representing a poorly graded soil.

### What is particle size analysis used for?

Particle size analysis is used to characterize the size distribution of particles in a sample. This analysis can also be used to measure the particle size of solid materials, suspensions, emulsions, and aerosols.

What is the purpose of a particle size distribution curve?

The particle-size distribution curves can be used for comparing different soils. Also, three basic soil parameters can be determined from these curves, and they can be used to classify granular soils. Them parameters are: Effective size.

## Which sand is better well graded or uniformly graded?

Well graded coarse-grained soil contains a good representation of all particle sizes from largest to smallest, with #12 percent fines. Poorly graded coarse-grained soil is uniformly graded, i.e., most of the coarse- grained particles are about the same size, with # 12 percent fines.

Why is D10 called the effective size?

The effective size of a given sample of sand is the particle size where 10% of the particles in that sample (by weight) are smaller, while 90% are larger. Usually this is denoted as the D10. The size distribution is represented by the Uniformity Coefficient, which enables you to see how well graded your sand sample is.

### What is CU value?

The uniformity coefficient (Cu) is defined as the ratio of D60 to D10. A value of Cu greater than 4 to 6 classifies the soil as well graded. When Cu is less than 4, it is classified as poorly graded or uniformly graded soil.

What is d90 particle size?

Thus, d10 = 83 µm, d50 = 330 µm, and d90 = 1600 µm means that 10% of the sample is smaller than 83 µm, 50% is smaller than 330 µm, and 90% is smaller than 1600 µm.

## How is the particle size distribution curve used in soil grading?

The particle size distribution curve is used to define the grading of soil. A soil sample is said to be well graded if it has all sizes of materials present in it. Poorly graded soil is a soil sample in which most of the particles are approximately of the same size.

Which is an example of a particle size distribution?

As an example, the particle-size distribution curves for two soils are shown in Figure 2. The particle-size distribution curve for soil A is the combination of the sieve analysis results presented in Table 2 and the results of the hydrometer analysis for the finer fraction.

### What is the difference between well graded sand and GW soil?

A well graded soil is a soil that contains particles of a wide range of sizes and has a good representation of all sizes from the No. 4 to No. 200 sieves. A well graded gravel is classified as GW while a well graded sand is classified as SW. Poorly Graded

What kind of soil has small particle sizes?

If more than 50% of the soil material has particle sizes greater than 0.075 mm that soil is called a coarse grained soil. Similarly if more than 50% of the soil material has particle sizes less than 0.075 mm that soil is fine grained soil.

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