Low plastic clay, high porosity but low permeability corresponds to which soil class?

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Multiple Choice

Low plastic clay, high porosity but low permeability corresponds to which soil class?

Explanation:
Fine-grained cohesive soils that are stiff and not very plastic commonly show high porosity but low permeability. Lean clay, a clayey soil with low plasticity, fits this pattern: the clay particles create a dense, tortuous pore structure that holds water in great abundance, yet the spaces between particles are so small that water moves very slowly. The combination of abundant pore space with very slow flow is characteristic of clay, making CL the best match. In contrast, sands would have much higher permeability due to larger gaps, and silts with low plasticity (ML) typically don’t exhibit as low permeability as clays.

Fine-grained cohesive soils that are stiff and not very plastic commonly show high porosity but low permeability. Lean clay, a clayey soil with low plasticity, fits this pattern: the clay particles create a dense, tortuous pore structure that holds water in great abundance, yet the spaces between particles are so small that water moves very slowly. The combination of abundant pore space with very slow flow is characteristic of clay, making CL the best match. In contrast, sands would have much higher permeability due to larger gaps, and silts with low plasticity (ML) typically don’t exhibit as low permeability as clays.

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