Vertical Jet Testing (VJT)

• E&H owns and operates a VJT apparatus to quantify the erosion rate of earth materials in terms of shear stress or stream power.
• The VJT apparatus consists of a vertical jet that is placed at some distance from the ground or material to be tested. The jet is fed by a constant head tank to erode the material below. Measurements are taken at a given time interval recording the depth of the eroded hole that is developing.
• Calculations to relate erosion rate to shear stress are conducted using a spreadsheet program prepared by G.J. Hanson and K.R. Cook, as part of the report Apparatus, Test Procedures and Analytical Methods to Measure Soil Erodibiltiy in Situ (Hanson and Cook, 2004).

Engineering - Science - Sustainable Solutions