What factors does the coefficient of permeability (k) depend on?

• A. Soil particle size, shape, structure, void ratio
• B. Degree of saturation, void connectivity
• C. All of the above
• D. Only soil particle size and shape

Answer: (C)

The coefficient of permeability (k) is a critical factor in geotechnical engineering, particularly regarding the movement of water through soil. It reflects how easily fluid can flow through the soil and is influenced by multiple factors.

One primary aspect is the soil particle size, which affects the pore sizes and spaces between the particles. Larger particles generally allow for easier water flow compared to finer particles, which can create more restrictive pathways.

The shape of the particles is also significant, as irregularly shaped particles can create more complex flow paths that may hinder permeability compared to more rounded particles. The structure of the soil, including how particles aggregate and the presence of clays, can influence the connectivity of voids, determining how water moves through the soil.

Additionally, the void ratio—essentially the amount of void space compared to the solid material—plays a crucial role. A higher void ratio typically means more space for water to flow, impacting the overall permeability.

Degree of saturation also affects the permeability, as fully saturated soils tend to have higher permeability than soils that contain air voids. The connectivity of voids—how well the voids are interconnected—further dictates the ease with which water can navigate through the material.

Given that k is influenced by all these factors