Correct option is B
In the plasticity chart, soils that plot above the A-line and have a liquid limit greater than 50% are classified as highly compressible clays (CH). This classification is based on the Unified Soil Classification System (USCS).
Important Key Points:
1. Plasticity Chart:
· A graph used in soil mechanics to classify fine-grained soils based on their liquid limit (LL) and plasticity index (PI).
· The A-line divides clays and silts:
· Soils above the A-line are clays.
· Soils below the A-line are silts.
2. Liquid Limit (LL):
· Indicates the water content at which soil changes from a plastic state to a liquid state.
· For clays with LL > 50%, they are classified as highly compressible clays (CH).
3. Soil Classification:
· Clays above the A-line with LL > 50%: Highly compressible clays (CH).
· Clays above the A-line with LL < 50%: Lower compressible clays (CL).
· Silts below the A-line with LL > 50%: Highly compressible silts (MH).
· Silts below the A-line with LL < 50%: Lower compressible silts (ML).