APPLICATION OF A STRAIN GAUGE ARRAY TO ESTIMATE SOIL MECHANICAL IMPEDANCE ON–THE–GO

A vertical smooth blade with an array of strain gauges was designed to dynamically measure mechanical impedance of soil at multiple depths. As the blade (tapered cantilevered beam) cuts through the soil, strain gauges detect deformation caused by varying soil resistance. Recorded strain data was used to estimate resistance pressure at different depths that caused the same deformation of the blade with known geometry and material properties. Verification of the analytical solution was performed in the laboratory by applying varying combinations of static loads. Field experiments involved on–the–go measurement of soil resistance coordinated using the global positioning system (GPS). Integrated resistance pressures were compared to cone penetrometer readings obtained from the same area within the field.