What are the Liquid Limit (LL) and Plasticity Index (PI) values associated with a soil classified as CH?

A soil classified as CH is recognized as a high-plasticity clay within the Unified Soil Classification System. To correctly characterize CH soils, their Liquid Limit (LL) and Plasticity Index (PI) values are essential.

For CH soils, the Liquid Limit is typically greater than 50, often falling within the range of 60 to 70 or higher, reflecting their high plasticity and moisture retention capabilities. The Plasticity Index, which is calculated as the difference between the Liquid Limit and the Plastic Limit, usually indicates a range from 20 to as high as 45 or more. A higher PI suggests that the soil has significant plasticity, which is characteristic of clays that remain pliable over various moisture contents.

Given these criteria, the option with LL = 63 and PI = 38 aligns with the expected values for CH soils, showcasing their high plasticity characteristics while maintaining cohesion and moisture content suitable for classification in this category.