anglular rock size and angle of internal friction relationship

[foreng]

Looking for some information that relates compacted angular rock grain size and angle of internal friction?

Trying to determine the steepest allowable fill slope for a temporary quarry access road? Fill is approx 11 m high with additional depth for surcharge included. The quarry has a varied gradation of rock on site. Client would like to target 1H:1V if possible.

From the tables I have I'm leaning towards 1.2H:1V. Stockpiles on site are at an angle of repose of around 1H:1V.

 

[dgillette]

Compacted hard angular shot rock could easily be 40 degrees, or more.

I would be hesitant to use 1:1 slopes.

 

[Delijosi]

1:1 slope suggests angle of repose of 45 deg. This is high. For phi of 38 to 42, I would suggest slope 1V:1.5H.

 

[foreng]

thanks for the advice