Kununurra Diversion Dam in the Kimberley Region of Western Australia was constructed in the early 1960s and has experienced seepage though both abutments since first filling. The central concrete gravity section and the adjacent zoned embankment are founded on rock; however, the embankments gradually lift off rock and are founded on Alluvium as they move away from the river. Analyses show that the coarse-grained Alluvium beneath the dam footprint is anticipated to be liquefiable and the fine-grained Alluvium will be prone to cyclic shear failure during a large earthquake. Remedial works comprising weighting berms, ground improvement and seepage control have been implemented to mitigate risks identified at the dam.
Mark Orr, Fabio Canzian, Michael Smith and Ming Lai
Keywords:
stone columns, liquefaction, backward erosion piping, dam, cut off trench, weighting berm
Publisher: DFI and PFSF