Correct Answer - Option 1 : fine sands-silt-clay-colloids
Explanation:
The surface tension (force) pulls the water upward till the height hc, at which the weight of water in the column is in equilibrium with the magnitude of the surface tension force.
\({h_c} = \frac{{4T\cos α }}{{{γ _w}d}}\)
where, α = contact angle
T = surface tension
d = diameter of capillary tube
γw = unit weight of water
- As increases in the fineness of the soil, capillary rises also increases means fine-grained soil has more capillary rise as compared to coarse-grained soil.
- So order of capillary rise : Colloids > clay > silt > fine sand
Because of the complex nature of the soil, a theoretical prediction of capillary rise in the soil is not possible. Terzaghi and peck suggested an approximate relationship to find capillary rise in-situ
\({h_c}(cm) = \frac{C}{{e{D_{10}}}}\)
where, C = Empirical constant
e = void ratio
D10 = effective grain size
