What does the symbol 'H' indicate in soil plasticity?

• A. Liquid limit below 50
• B. Liquid limit above 50
• C. Clay with low plasticity
• D. Peat and highly organic soil

Answer: (B)

The symbol 'H' in soil plasticity is used to indicate that a soil has a liquid limit greater than 50. This classification is part of the Unified Soil Classification System (USCS), which is commonly used in geotechnical engineering to describe the plasticity of soil materials.

Soils with a liquid limit above 50 are typically more susceptible to changes in moisture content, making them behave differently under load and affecting their engineering properties. This characteristic is essential for understanding the behavior of soil in construction and foundation design, as it can indicate higher plasticity, potentially leading to issues like swelling or shrinkage.

Recognizing the significance of the liquid limit in the 'H' designation helps engineers and geologists to assess the stability and usability of soils in various construction applications.