Slope stability

[soiledup]

A client of mine is looking at placing single residential unit on the crest of a slope. An approximation is that the slope has 1-1.5m head deposit covering slightly weathered granite. There is no granite exposure to map joints, is orientated coring the cheapest / quickest way of measuring fracture sets to assess slability of the rock?

Any advice greatfully recieved because as usual the client doesn't want great expense,,,

Kind regards

Soiledup

 

[exploengineer]

Cheapest would be to strip it off and map the joint sets. If you are not familiar with this process, you can buy some software called Wipjoint. Available at Wipware. But, I would actually drill and strip. Bewteen the two, you would be able to create a great model and take away the guess work.

I specialize in explosives engineering/blasting and I'm a geologic engineer. So, I'm exposed to this type off project daily. If the granite is competant, strip of the dirt, rip the weathered material, blast the foundation and go. You may need some foundation anchors/rock bolts to be on the safe side.

Sorry about the rambling.



Frank Lucca M.I.Exp.E.

http://www.terradinamica.com

 

[epongra2]

I assume that the local grading codes won't allow the striping of overburden over the site. If possible, get a backhoe out to the site and dig a number of test trenches. This will allow for direct observation and mapping of the geologic structure, depths of weathering, continuity and roughness of joints, etc.