Hey emmgjld, those values you show there are building code "defaults"? So one might consider them conservative for your situation in CO? That is interesting that you have actual stated forces to use in design in risk situations..... We don't have those in OR.
See photo of a road fill that became part of the debris flow. This was a catastrophic event, not failure through incremental erosion which then led to failure. Debris flow came from higher up the gulley and blew out this...
I backed in phi and c using Hoek's method but obviously the bedding planes (as a discontinuity) are not the same as the other joint sets since they definitely control failure on the one side of the creek. There is not one plane that is the controlling plane but a whole section of 1" to 6"...
Perhaps there are two ways to think of the problem:
1) If you trust the design of the berm to be adequate, you could just make sure that the new foundation could support at least the strength lost by the excavated soil plus the pressure of the soil on the berm side of the foundation. I would...
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...
That link didn't work for me.... I really don't think testing on any type of disturbed sample will get me anything. Once the material is disturbed it can't be reassembled into its original shape to be meaningful. Any testing at that point would return a minimum phi and i already pretty much...
Here is the link to the publication. It has a treatment for various types of rock fabric (Chapter 6).http://geotechnicalinfo.com/usace_rock_foundations.pdf
Here is the NAV Fac for Rock. See citation.
DEPARTMENT OF THE ARMY EM 1110-1-2908
U.S. Army Corps of Engineers
CECW-EG Washington, DC 20314-1000
Manual
No. 1110-1-2908 30 November 1994
Engineering and Design
ROCK FOUNDATIONS
thread255-253888
Looking to perform a preliminary (recon level) slope stability analysis for a through-fill held up by a wall on top of a ridge of moderately weathered fractured basalt. Fractures would be 4-inches to 12-inches wide, closed, with more weathering along the fractures than within...
