Darcy's law v=ki describes water flow through soil.
Darcy's law v=ki with hydraulic conductivity k (10⁻² m/s gravel to 10⁻¹⁰ m/s clay). Tests: constant head (sands), falling head (silts and clays), pumping tests in the field. Seepage under dams is analysed with flow nets. Piping occurs at critical hydraulic gradient i≈1.
Seepage under a sheet pile wall reduces exit gradient.
Permeability controls how fast water flows through soil, which matters for drainage, dams, seepage and pumping of excavations.
Darcy's law v=ki describes water flow through soil.
Permeability controls how fast water flows through soil, which matters for drainage, dams, seepage and pumping of excavations.
The flow velocity through soil is proportional to the hydraulic gradient, with permeability as the constant of proportionality.
Clean gravels and coarse sands, while clays have very low permeability and restrict water flow.
Typical applications include designing a drainage layer behind a retaining wall, estimating the seepage under a dam and predicting how fast a trench fills with groundwater during excavation.
Study "Compaction" first (topic 29 of 112 in Civil & Structural). It covers the groundwork this topic builds on.
Flow net. Quicksand. Filter design.
Seepage under a sheet pile wall reduces exit gradient.
The next topic is "Effective stress", which builds directly on this one.
It is classed as Beginner in Civil & Structural (topic 30 of 112). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
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