Automated Down-Hole Testing System for Drilled Shaft Slurry

Proper performance of slurries used to stabilize drilled shaft excavations is achieved by ensuring that the density, viscosity, and sand content stay within empirically defined limits set by past experience, research findings, or manufacturer recommendations. When slurry properties fall outside these limits, the excavation walls can collapse or material can become entrapped within the shaft concrete, or both. Therefore, it is imperative that the slurry be periodically tested starting prior to its introduction into the excavation. Because all measurements are performed manually, slurry testing is time-consuming. However, with the overwhelming advances in digital devices, it is not unreasonable to assume that slurry property tests are equally applicable to this trend. This paper introduces a prototype down-hole slurry testing system that was shown to be surprisingly easy and fast to use despite the experimental nature of the design. One of the demonstration shafts sampled at six different depths was tested in less than 10 min. In contrast, conventional, manually performed testing can take more than an hour to perform the same number of tests.