Amount of "Crushed" rockfill in a Rockfill Embankment/Dam

[BigH]

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.

 

[miningman]

Ive seen reference to this value of 17% somewhere else on eng tips but I cant remember the context or details.

 

[GeoPaveTraffic]

Never heard of a limit of crushed rock in a rock fill dam. Last dam that I finished had 100% crushed rock in the rock shells. Additionally most larger earth and rock fill dams constructed in the mid-west US have fairly thin soil cores with large rock shells and the rock shells are essentially 100% crushed rock excavated from the spillway.

Mike Lambert