Fully softned shear strength

[geoPhD]

I'm currently interested in testing Fully Softened Shear Strength (FSS) on Low and High Plasticity clays and further using FSS parameters to analyze slope stability.

My source of information is limited to Tim Stark's work on Torsional Ring Shear ( ASTM 7608-10) and Steven Wright's report (FHWA-TX/-07/0-5202-3). As far as I know we can test FSS using torsional, direct shear and triaxial testing procedures.

My questions are:

- Does anybody know the sample preparation steps required for testing?

- Since the FSS failure envelope is a curve and normal stress-dependent, what value of friction angle should we use for modeling?

 

[fattdad]

prepare a slurry at the liquid limit and normally consolidate in the DDS. Shear and use peak strength for FSS. CGPR (Virginia Tech) held a workshop and this is the closest approach to replicating the TSS results. Most labs have the DDS.

There are labs that can do TSS and as an undisturbed sample is not needed, shipping is no issue.

f-d

¡papá gordo ain’t no madre flaca!