143-1 In Situ Shear Strength Data Logging and TDR.

Poster Number 2403

See more from this Division: SSSA Division: Soil Physics
See more from this Session: Advancing Measurement Technology in Soil and Environmental Physics: An Original Research Instrumentation Showcase (includes student competition)

Monday, November 4, 2013
Tampa Convention Center, East Exhibit Hall

G. Clarke Topp, David Lapen and Mark Edwards, Agriculture & Agri-Food Canada, Ottawa, ON, Canada
Poster Presentation
  • In Situ Shear Strength Data Logging and TDR_POSTER_80000.pdf (1.0 MB)
  • Abstract:
    Few options exist for convenient field measurement of soil shear strength parameters, especially at different water contents. The Cohron portable sheargraph, a torsional shear device, for in situ measurement of field shear strength (Cohron 1963) records both normal and shear stresses during the shear occurrence. Data retrieval involved digitization of the graphs and soil sampling for gravimetric determination of water content – two tedious and time consuming processes.  Two load cells – one for shear stress and one for normal stress – were installed in lieu of the coil spring on the sheargraph. The soil grouser head was reconfigured to include a TDR transmission line allowing water content measurement just before shear strength determination. This reconfigured Cohron shear logger was used to measure cohesion and friction angle for two soils – sandy loam and clay loam – at two water contents.

    See more from this Division: SSSA Division: Soil Physics
    See more from this Session: Advancing Measurement Technology in Soil and Environmental Physics: An Original Research Instrumentation Showcase (includes student competition)

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