Comparing strength values on either side of a gulley.
Comparing strength values on either side of a gulley.
(OP)
I have a dipping siltstone (soft, jointed, bedded rock, R1) which dips into the slope on one side of a creek and out of the slope on the other side. I have back-calculated strength parameters for the natural stable slope on the in-slope dipping side and I am wondering which values would change for the out-slope dipping analysis. Should phi and c both change to weaker values? Which strength parameters should be affected by a change in dip direction?
The one side of the creek is stable and the other side has several failures which shows differences in stability of the natural slopes. Of course one can choose various combinations of phi and c to arrive at whatever FOS is assumed, but in the same formation shouldn't one of the values remain the same as on the other side?
I am modeling initial, pre-failure values and have assumed the stable slope to be at a FOS of 1.1 which I am hoping will give me "minimum" strength values to apply elsewhere. I want to do the same for the out-slope dipping side.
I began by using RocLab to estimate phi and c to apply to a limit equilib. analysis...
Ideas?
The one side of the creek is stable and the other side has several failures which shows differences in stability of the natural slopes. Of course one can choose various combinations of phi and c to arrive at whatever FOS is assumed, but in the same formation shouldn't one of the values remain the same as on the other side?
I am modeling initial, pre-failure values and have assumed the stable slope to be at a FOS of 1.1 which I am hoping will give me "minimum" strength values to apply elsewhere. I want to do the same for the out-slope dipping side.
I began by using RocLab to estimate phi and c to apply to a limit equilib. analysis...
Ideas?
RE: Comparing strength values on either side of a gulley.
I suggest you treat this as a rock slope and analyze it as such. If you don't have experience analyzing rock slopes, get with someone who does and have them teach you.
Good Luck.
Mike Lambert
RE: Comparing strength values on either side of a gulley.
Would you use a structural analysis to do this problem?
To address your other comment, I don't have this specific experience and neither does my peer whom I work with because we don't normally delve into this area. We are surrounded by foresters!