Field Device to Measure Viscosity, Density, and Other Slurry Properties in Drilled Shafts

Proper performance of mineral slurries used to stabilize drilled shaft excavations is maintained by assuring the density, viscosity, pH, and sand content stay within state specified limits. These limits have been set either by past experience, research findings and/or by manufacturer recommended values. However, field slurry testing is time consuming as all measurements are manually performed. With the overwhelming advances in digital down-hole devices, it is not unreasonable to assume that slurry property tests are equally applicable to this trend. The most commonly used test to indicate slurry viscosity is the Marsh Funnel Test which is essentially a timed flow for a fixed volume of slurry to exit a falling head funnel. Using a library of unique pressure versus flow rate responses for a wide range of slurry viscosities, an automated downhole device was designed and tested that incorporated these information to estimate viscosity in the excavation without the need to remove slurry in order to test. Direct measurement of slurry density was also incorporated into the device and the sand content was computed from density and the viscosity where the suspended solids that make up the density stems from both the slurry products and the soil cuttings. The prototype down-hole slurry testing system was shown to be surprisingly easy and fast to use despite the experimental nature of the device. A shaft sampled at 6 different depths was tested in less than 10 minutes. In contrast, conventional, manually performed testing were estimated by contractors to have taken more than an hour to perform the same number of tests.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 265p

Subject/Index Terms

Filing Info

  • Accession Number: 01608683
  • Record Type: Publication
  • Contract Numbers: BDV25 TWO977-09
  • Files: TRIS, ATRI, STATEDOT
  • Created Date: Aug 5 2016 10:13AM