Department: University of Delaware. Department of Civil and Environmental Engineering.
Publisher: ASTM International
Date Issued: 2008
Abstract: Fast and slow ring shear tests were performed in the Bromhead ring shear device to examine the effect of
the displacement rate on the shear strength measured along slickensided discontinuities in Rancho Solano Fat Clay. For
each test, initial drained shearing was performed at a displacement rate of 0.018 mm/min, fast shearing was performed
at a rate of 44.5 mm/min, and drained shearing was recommenced at a displacement rate of 0:018 mm/min. Significant variations in measured post-peak shear strengths were observed, and problems with the pore pressure response in the
soil surrounding the slickensided plane are discussed. As a result of these problems, it was concluded that fast Bromhead ring shear tests may not be suitable for evaluating the effects of fast shearing on the strengths of slickensided surfaces.
Meehan, C. L., Brandon, T. L., and Duncan, J. M. (2008). Measuring Fast" Shear Strengths
Along Slickensided Surfaces in the Bromhead Ring Shear." Geotechnical Testing Journal, ASTM, 31(3), 239-242.
(doi:10.1520/GTJ101325)