What is coefficient of uniformity?

What is coefficient of uniformity?

uniformity coefficient (u-ni-form’-i-ty). A numerical expression of the variety in particle sizes in mixed natural soils, defined as the ratio of the sieve size through which 60% (by weight) of the material passes to the sieve size that allows 10% of the material to pass.

How do you calculate uniformity coefficient?

The size distribution is represented by the Uniformity Coefficient, which enables you to see how well graded your sand sample is. This is done by taking the D60 and dividing by the D10.

What is coefficient of curvature?

The coefficient of curvature is a measure of gradation of particles and given by the following expression: Cc = (D30)2/D60.D10. Where, D60 = Size of the particle corresponding to 60% finer.

Is code for coefficient of uniformity?

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. Uniformly graded soil has identical particles with Cu value approximately equal to 1.

What is CU and CC in sieve analysis?

Cu – Uniformity coefficient. Cu = D60/D10. Cc – Coefficient of curvature.

How is D10 D30 D60 calculated?

The particle diameters defining 10%, 30%, and 60% finer from the grain-size distribution curve are estimated as: D10 = 0.14 mm , D30 = 0.27 mm, and D60 = 0.42 mm.

What is C in geotechnical engineering?

Between the soil particles there are the internal forces that the soil can be offer to resist failure and sliding a long any plane inside it. One of there is cohesive strength (C) and the other is angle of internal friction (φ). But the soil in general called C – φ soil.

What is D10 D50 and D90?

D10: The portion of particles with diameters smaller than this value is 10% D50: The portions of particles with diameters smaller and larger than this value are 50%. Also known as the median diameter. D90: The portion of particles with diameters below this value is 90%.

What is the definition of coefficient of permeability of soil?

The coefficient of permeability (K) is the velocity in meters or centimeters per second of water through soils. Fine-grained soils such as clays might have values of around 10-8meters/sec or lower, or a sand and gravel formation could be 10-4meters/sec or higher.

How is the uniformity coefficient and the coefficient of gradation related?

The uniformity coefficient (Cu) and the coefficient of gradation (Cc) are the measures of soil gradation. These coefficients help to classify the soil as well as graded or poorly graded ones. 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.

How is the uniformity coefficient used to classify soil?

These coefficients help to classify the soil as well as graded or poorly graded ones. 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 does the uniformity coefficient of filter sand mean?

Uniformity coefficient means from a particle-size distribution curve it is, the ratio of the 60 percent grain size to the 10 percent grain size. Uniformity coefficient means the number representing the degree of homogeneity in the distribution of particle sizes of filter sand or other granular material.

How is the uniformity coefficient of a sieve calculated?

Uniformity coefficient ” means a numeric quantity calculated by dividing the size of the sieve opening which will pass sixty percent of a sample by the size of the opening which will pass ten percent of the sample on a weight basis.