Just wondering if anyone has heard/read about limiting the amount of crushed boulders being put into a rockfill embankment/dam - with special emphasis, perhaps, on expected settlements when inundated or subjected to high intensity seismic. We are talking the crushing of 400 to 700 mm boulders and then remixing back into the natural alluvium. I am fully aware that many embankments and dams are of crushed/blasted rock. But, someone on a job of which I am aware says that no more than 17% can be of crushed boulders. Weird - not 15%, not 20% but 17%

Thanks if you can help.