Sieve analysis is a method used to determine the grain size distribution of soils that are greater than 0.075 mm in diameter. It is usually performed for sand and gravel but cannot be used as the sole method for determining the grain size distribution of finer soil1.
The procedure involves obtaining a representative oven-dried soil sample and pulverizing it as finely as possible using a mortar and pestle or a mechanical soil pulverizer. A soil sample of about 500 g is obtained and its mass is determined. The sample is then placed on top of a stack of sieves with different mesh sizes, with the largest mesh size at the top and smallest at the bottom. The stack is then placed in a mechanical shaker for 10 minutes12.
The amount of soil retained on each sieve is weighed and recorded. The percentage of soil retained on each sieve is then calculated by dividing the weight of soil retained by the total weight of soil sample taken. A graph of percentage finer versus particle size is then plotted1
Sieve analysis of soil is a method used to determine the particle size distribution of a soil sample. This method is essential in soil mechanics, as the particle size distribution of a soil sample affects its physical and mechanical properties.
The sieve analysis process involves passing a soil sample through a series of sieves with different-sized openings, starting from the largest at the top to the smallest at the bottom. The soil particles are separated based on their size, and the weight of soil retained on each sieve is recorded. The percentage of soil retained on each sieve is calculated, and a particle size distribution curve is plotted.
The following are the steps involved in sieve analysis of soil:
Sampling: A representative soil sample is collected from the site using an appropriate method.
Preparation of sample: The soil sample is air-dried, and any visible debris or organic matter is removed from it. The sample is then broken down into smaller particles to ensure homogeneity.
Weighing of sieves: The sieves are weighed, and their weights are recorded to determine the weight of soil retained on each sieve accurately.
Sieving: The soil sample is poured onto the top sieve with the largest opening, and the stack of sieves is then shaken for a specific period of time. The soil retained on each sieve is collected and weighed.
Calculation: The weight of soil retained on each sieve is calculated and expressed as a percentage of the total weight of the soil sample. The percentage of soil passing through each sieve is also calculated by subtracting the percentage retained on each sieve from 100. The data is then plotted on a particle size distribution curve.
Interpretation: The particle size distribution curve provides valuable information about the soil's physical and mechanical properties, such as its permeability, compressibility, and shear strength. A well-graded soil has a particle size distribution that is evenly distributed, while a poorly-graded soil has a narrow range of particle sizes.
In conclusion, sieve analysis of soil is an important method for determining the particle size distribution of soil samples. This information is essential in designing foundations, retaining structures, and other geotechnical structures
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