Fundamental hydraulic property of soils The property of a soil that permits water to flow or percolate through its pore network under a hydraulic gradient is called:

Introduction / Context:
Flow of water through soils governs settlement rates, consolidation, dewatering, and stability. The material parameter that describes the ease of flow through a saturated soil is central to seepage analysis and filter design.

Given Data / Assumptions:

• Consider Darcy’s law conditions (laminar flow).
• Fully saturated soil matrix unless otherwise noted.
• Hydraulic gradient drives flow.

Concept / Approach:

Permeability (hydraulic conductivity, k) characterizes how readily water passes through soils. It depends on grain size, void ratio, soil fabric, and fluid properties. Moisture content is simply the mass ratio of water to dry soil; capillarity is an unsaturated effect causing upward water movement, not the bulk flow property.

Step-by-Step Solution:

Verification / Alternative check:

Laboratory tests (constant or falling head) measure k directly, confirming it is the parameter of interest for percolation.

Why Other Options Are Wrong:

Moisture content is a state parameter, not a flow property; capillarity is a suction-driven rise phenomenon; “none” is incorrect; shrinkage limit is an Atterberg limit for clays.

Common Pitfalls:

Equating capillary rise height with permeability; ignoring temperature dependence of k through fluid viscosity.

Final Answer:

Permeability