Estimating Bearing Capacity on Highly Fractured Rock
Estimating Bearing Capacity on Highly Fractured Rock
(OP)
During my geotechnical carrier I am always having a problem of estimating an allowable bearing capacity on highly fractured, highly to moderately weathered rock where RQD is 0 and no sample for UCS or Point Load Test. Some times I dwell in British Standard BS8004:1986 to derive the bearing capacity emperically but I have never be confortable with the results which most of the time are conservative. Please if thre is anybody who can assist me in this area i will be very grateful.





RE: Estimating Bearing Capacity on Highly Fractured Rock
Anyway, I've had the same problem for years, until I recently came across a satisfactory operative solution which involves use of a specific published technique. Very good with drillcores with RQD=0.
You should have a previous knowledge of the Hoek & Brown, 2002 method though which is fully explained in the Rocscience site, along with a freeware and scientific handbook.
I'm going and give you the details about the relevant journal paper as soon as I can retrieve them.
RE: Estimating Bearing Capacity on Highly Fractured Rock
Osgoui et al. 2010: An assistant tool for the geological strength index to better characterize poor and very poor rock masses, International Journal of Rock Mechanics & Mining sciences, 47, 2010
Using this 'assistant' method and the Hoek & brown procedure, you can get the Mohr-Coulomb parameters and use them in the usual bearing-capcity formulas.
Or you can get the Hoek-brown parameters and use them in more specific methods.
I'm going to attach one real life example of this procedure.
RE: Estimating Bearing Capacity on Highly Fractured Rock
Thank you for your valuable info. infact i was outdated as i know only Hoek and Bray book for Rock slope engineering but i dont know this other book by Hoek and Brown. I will look how to get it through Amazon.
Best regards,
RE: Estimating Bearing Capacity on Highly Fractured Rock
if you download the free roclab software, you'll get a few reference papers on the HB method.
Somewhere in the web there is even a whole handbook available, whose link I have to retrieve though.
This is the link to the roclab software download:
http://download.rocscience.com/products/RocLab.asp
RE: Estimating Bearing Capacity on Highly Fractured Rock
http://www.rocscience.com/education/hoeks_corner