Grain, Soil and Water Pressure: Capillarity & Suction Pressure Flashcards
1
Q
What is capillary action in soil?
A
The upward movement of water due to suction in narrow pores.
2
Q
How does capillary action vary between sand and clay?
A
Soil Type Capillary Rise
Sand 20–30 cm
Clay Up to 20 m
3
Q
What happens to effective stress above the groundwater table
A
Capillarity creates negative pore pressure (suction), increasing soil strength.
4
Q
Why does clay remain wet above the groundwater table?
A
Due to strong capillary suction, clay holds water even above the phreatic level.
