Classification of Fine Grained Soil as per Indian Standard Classification System

Explanation:

The Indian Standard Classification System for soil categorizes soils based on their properties, particularly their grain size distribution and plasticity. According to this system, the given soil, which is fine-grained, is classified as CI.

Plasticity of Soil:
Plasticity refers to the ability of soil to deform without cracking or breaking. It is an important property used in soil classification. The plasticity of soil is determined by the percentage of water content present in the soil.

Water Content Range:
The given soil is found to be plastic in the water content range of 26-48%. This means that the soil exhibits plastic behavior within this moisture range.

Classification:
Based on the plasticity range, the given soil is classified as CI according to the Indian Standard Classification System. CI stands for Clayey soil with low to medium plasticity.

Significance of CI Classification:
The CI classification indicates that the given soil is predominantly clayey in nature and possesses low to medium plasticity. This information is valuable in various civil engineering applications, including foundation design, slope stability, and construction material selection.

In terms of engineering properties, CI soils typically exhibit high compressibility, low permeability, and significant shrink-swell potential. These characteristics have important implications for construction projects and can influence design decisions.

Conclusion:
The given soil, with its plastic behavior in the water content range of 26-48%, is classified as CI according to the Indian Standard Classification System. This classification helps in understanding the engineering properties and behavior of the soil, which is crucial for planning and executing civil engineering projects.