ODA01: CENTRIFUGE MODELING OF VERTICAL DIFFERENTIAL SETTLEMENT-INDUCED CRACKS IN A LEVEE

A centrifuge test (ODA01) was used as a proof-of-concept test to investigate the effect of vertical differential settlement on crack formation in a model levee. The Yolo loam embankment levee and its foundation were 250 mm and 62.5 mm high in prototype scale, respectively. Viscous pore fluid was used to simulate water behind the levee at a height of 225 mm and the test was conducted at 40g. The foundation of the levee included a moving part (a hydraulic table) and a non-moving part (a jointed wood table). The hydraulic actuators were extended to a maximum height of 25 mm before the start of the test. In the centrifuge, the hydraulic table was lowered to a maximum settlement of 25 mm to simulate the differential settlement of the levee. Hairline, transverse and longitudinal cracks were effectively induced in the levee through this vertical differential settlement. Furthermore, seepage flow was initiated through the cracks. The seepage flow stopped after some time without significant erosion, likely due to swelling of the soil around the crack and lowering of the upstream water level.