Prices Fork Laboratory

This off-campus laboratory located about three miles from the Virginia Tech Campus at the Price’s Fork Research Station. This laboratory houses the Instrumented Retaining Wall Facility, the In Situ Test Instrument Calibration Chamber, and two drill rigs.

The Instrumented Retaining Wall Facility has been developed to study both the factors that control the magnitudes of earth pressures induced by compaction and the influences that wall movements have on earth pressures. The wall, which is 7 feet high and 10 feet long, is instrumented with load cells and pressure cells so that the normal loads, shear loads, and normal pressure distribution on the wall can be measured.

The In Situ Test Instrument Calibration Chamber allows the evaluation of in situ test instruments under carefully controlled conditions. The chamber accommodates a soil specimen 5 feet in diameter by 5 feet tall. The chamber consists of a steel cylinder, with bottom and top plates that are bolted onto the cylinder. The soil specimen is contained within a cylindrical flexible liner, and confining pressure may be applied using either water or air in the annulus between the sample and the cylinder walls. Vertical stress is applied independently through air pressure bags which act on the free-floating base plate beneath the sample. Stresses of up to 100 pounds per square inch can be applied to the test specimen. The cone is inserted through a centrally located hole using a 5 ton, constant rate of displacement, hydraulic ram.

There are two drilling rigs with the necessary equipment for employing a variety of sampling and in situ testing techniques. Our Mobile B-80 drill rig is mounted on a four-wheel-drive Ford F‑700 chassis and is capable of drilling to depths exceeding 300 feet in soil. Our Sprague-Henwood, skid-mounted drill rig is designed for taking core samples of rock. This rig is portable and is ideally suited for remote applications. Our inventory of in situ and ancillary test equipment includes the following:

  • 5 – 4.2 cm2 cone penetrometers (developed at Virginia Tech)
  • 10 cm2 standard cone penetrometer (Fugro)
  • 2 – 10 cm2 piezocone (Hogentogler)
  • 15 cm2 standard cone penetrometer (Hogentogler)
  • 2 Marchetti Dilatometers
  • 4 in O.D. Cambridge Self-Boring Pressuremeter
  • 3 in O.D. 9-arm Cambridge Self-boring Pressuremeter
  • 12 channel signal enhancement seismograph (EG&G Geometrics)
  • Magnetometer (EG&G Geometrics)

Geosynthetic pullout device. This test device consists of a 3 x 5 foot plan dimension by 1-foot high soil volume. Dual hydraulic rams can apply up to 20,000 pounds of horizontal pullout force at less than 0.04 inches per minute displacement rate.