Abstract
Flume experiments were conducted to investigate the headcut erosion process in heterogeneous soil stratum. A composite fill was prepared on flume bed composed of coarse sand at bottom and PVC fine particle at top. Adhesive color spray applied on the top surface resisted the surface erosion as well as ensured the headcut development. The effects of hydraulic and geometric condition on headcut migration speed, unaffected by downstream deposition, were analyzed. The experimental result showed the plunge pool morphology remained unchanged with time for a given flow discharge. The migration speed increased with flow discharge and headcut height. Power functions were introduced to correlate the migration speed, flow discharge and headcut height. A conceptual model was introduced to explain details of the headcut migration process. The result of conceptual model reasonably agreed with the experimental data.
