A clay whose shear strength is decreased to a fraction of its former value by remolding is called

A clay whose shear strength is decreased to a fraction of its former value by remolding is called

• A. A stiff clay
• B. A dry clay
• C. A sensitive soil
• D. A high-plasticity clay

Answer: (C)

The idea being tested is soil sensitivity—the drop in shear strength that occurs when a soil is disturbed or remolded. Some clays have a natural fabric and bonding that give higher strength in undisturbed state; when you remold them, that fabric breaks and the shear strength falls dramatically, often to only a fraction of what it was. So a clay that loses most of its strength on remolding is called a sensitive soil. This differs from a stiff clay (rigidity), a dry clay (moisture content issue), or a high-plasticity clay (related to Atterberg limits, not remolded strength).

The idea being tested is soil sensitivity—the drop in shear strength that occurs when a soil is disturbed or remolded. Some clays have a natural fabric and bonding that give higher strength in undisturbed state; when you remold them, that fabric breaks and the shear strength falls dramatically, often to only a fraction of what it was. So a clay that loses most of its strength on remolding is called a sensitive soil. This differs from a stiff clay (rigidity), a dry clay (moisture content issue), or a high-plasticity clay (related to Atterberg limits, not remolded strength).