Geo-Trends Review

See Hoek's practical engineering Manual p. 116 and 117.  https://www.rocscience.com/documents/hoek/corner/Practical-Rock-Engineering-Full-Text.pdf This is for the plane failure, but you would solve it for a wedge along the intersection plane using the apparent dip and strike.

This could easily happen in a clay if the clay is not fully saturated. Remember phi is equal to zero because, the increment of pressure goes into pore pressure, but if you are not fully saturated this will not happen.

You should look at your clay properties to assess all relevant conditions such as permeability, gradation (is it pure clay or does it contain silt and/or sand) degree of consolidation (OCR), and as the previous responder noted, degree of saturation.  If the test is run at a rate that permits drainage of excess pore pressures, you will see friction.  If your sample is very dense and dilating under shear, you may also see a frictional behavior. You should also check your shear device to assure that there is no frictional contact between the upper and lower portions of the shear box and that the load is centered over the sample without contacting the shear box.  Sometimes it's the little things that matter. 

Hi Mohamed,

I do not know if you're still searching for laterally loaded barrettes. If so, please let me know, I could be able to help.

Regards,

hi mohamad ,

i have a paper about this and case study if you're still searching you can reply. 

Thank you all for your kind replies

I have found a case study for laterally loaded barrette, but yes, if you can thankfully share what you have, i would be greatful. 

Hi Azaiez, I can send it to you using the messaging option of GeoWorld, as it is best not to share it publically (for copyright reasons). I sent you a contact request

Hi Dimitrios 

Thank you for your kidness, i have just accepted the request.

Just sent. Let me know you got this.

You may perform point load tests on the rock material and u can correlate it with Ucs value.   The angle of repose can be consider in calculating allowable bearing capacity.The Angle of Repose because Rock Triaxial instruments are rarely available in the local industry. Further reading is recommended on intermediate Geo-Materials ”IGM

Bowles (fifth edition, p279) suggests that you can make calculation of the bearing capacity of the ground, according to the same equations that are derived for soil materials, when you have value of RQD<25. Make the best estimation of the parameters of the ground (fi and C), for the given stress state.

Regards

Hi,

All the above recommendations are great. I would advise you to consider the rock formation as a cohesionless soil with 0 cohesion and fi above 35 degrees. You can improve the design by considering it to be an intermediate Geo-Material, as one of the respondents above has commented. You can solve this problem with the "ALLPILE" program, it has a special provision for this kind of material.

Regards,

hi it is very difficalt to estimate the rock bearing capacity in UCS if its RQD value is zero hence the very important thing is that geotecnicall oberve the geological formation/orentation of the rock, discontiniuty, fault and other gaps  of the area/pit/ and identify weather it is suitable or saviere then we can considers as soil or weatherd rock and calculate the bearing capacity using the adopted formmulas 

Cut-off walls are a classic choice for somethign like this, but option (b) is likely to be more economic. It depends on the project requirements, and the risk level you are willing to take. However, the (d) is a necessity in either case.