Bunding Material: Stone & Rubble Mechanics: Interface Friction Kinetics, Hydraulic Stability, and Energy Dissipation in Rockfill Bund Structures
Stone bunding—comprising stone-pitching, dry rubble bunds, and loose rock check dams—serves as a primary soil and water conservation technique across semi-arid terrains, sloping watersheds, and agricultural catchments. Constructed using locally available angular stones or coarse cobbles laid along elevation contours, stone bunds reduce surface runoff velocity, promote groundwater recharge, retain topsoil sediments, and mitigate severe sheet and gully erosion through porous hydraulic dissipation. The hydraulic performance of a permeable stone bund structure relies on balancing flow deceleration with internal pore discharge. The non-linear flow velocity ($v$) through the interstitial voids of coarse stone media under turbulent flow conditions is modeled using the Forchheimer Non-Darcy Porous Media Flow Equation : $$-\frac{dh}{dx} = a \cdot v + b \cdot v^2 = \frac{\nu}{g \cdot k} \cdot v + \frac{C_F}{g \cdot \sqrt{k}} \cdot v^2$$ Where $\frac{dh}{dx}$ is the hydraulic gradient, $a$...