Instrumenting Pencel Pressuremeter Control Unit to Simplify Data Collection, Reduction, and Analysis

The Pencel pressuremeter control unit was instrumented to simplify digital recording, data reduction, and analysis of soil parameters. Digital signals from the instrumentation were collected through a commercially available data acquisition package, known as an automated pressuremeter (APMT), which produced reduced stress–strain data and allowed operators to determine the critical parameters. The instrumented system saved significant time. Data from numerous tests were evaluated for accuracy. Both clays and sands were included in the comparison. A digital pressure transducer was plumbed into the control unit, and a linear potentiometer was connected directly to the piston to produce digital volumes. The digital equipment improved the accuracy of the pressures more than ten-fold and eliminated gear backlash associated with the existing volume counter. The backlash affects the moduli more than the limit pressures, especially those associated with unload–reload loops of stiffer soils. Pressure-versus-time data for each injected volume increment were evaluated to determine when the pressures stabilized. APMT indicated that the pressure stabilized between 10 and 80 s for the sands and clays evaluated. The volume increment stabilization period was defined as the time required for the pressures to stabilize.


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  • Accession Number: 01046314
  • Record Type: Publication
  • ISBN: 9780309104302
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 5:16PM