Effect of cyclic wave loading on scouring stability of geotube dams

Cyclic wave loading on geotube dams creates a cyclic flow in seams between geotubes regime distinct from the uni-directional flow that has been previously studied. A new laboratory apparatus was used to investigate the effects of hydraulic conditions on the core sand of geotube dams with seams between tubes. With this apparatus, a series of tests was conducted. Various maximum pressure heads (0.25, 0.3, 0.35, and 0.4 m), periods of cyclic wave loading (6, 7, 8, and 10 s) and particle porosities (34%, 35%, 40%, and 45%) were used in this test series. In the test series, the erosion development process of sand was analyzed. The results also indicate that the sand in the dam core can still perform satisfactorily after being scoured into the seam and extending a certain length. This critical length was found to be a function of the sand porosity, cycle period and maximum pressure head.