An improved solution to capillary rise of water in soils

Evaluating the rate and maximum height of capillary rise is of prime interest in unsaturated soil mechanics. Antecedent solutions to this problem have dwelled mostly on determining the maximum capillary rise height, overlooking moisture and suction changes in the capillary region. A comprehensive improved solution for the capillary rise of water in soils is presented. Salient features of the formulation including; consideration of initial soil suction (if any) prior to capillary rise, and determination of water content variation in the capillary region are elaborately discussed. Results reveal that suction head variation within the capillary region is non-linear, where the curvature decreases as water rises to higher elevations. The solution is verified and compared with existing solutions, by means of two sets of experimental data available in the literature. The comparison suggests that the improved formulation is more accurate and versatile than previous solutions for capillary rise.