Wing sounding

Probe tip of a wing probe

The wing sounding is a test method with the help of which the shear strength of a water-saturated, undrained as well as cohesive and organic soil can be examined. The method is used in road construction and earthworks . Basically, the experiment indicates how much resistance the ground opposes to the turning movement of a rod equipped with wings (wing probe). The higher the shear strength of the floor, the higher the measured resistance.

The first preforms of the wing probe were developed and patented by Degebo in 1929 , but the actual development only took place elsewhere after the Second World War.

Wing shear test

The experiment is carried out on site (in situ), for this purpose the probe is pressed into the ground. The overlap should be ≥ 30 cm. It is then turned at a constant angular speed (30 ° / min) until the floor breaks. The maximum torque determined in this way enables the shear resistance to be calculated using the following formula: (with a plate dimension of H = 2 D)

${\ displaystyle \ tau _ {FL} = {\ frac {6 \ cdot M} {7 \ cdot \ pi \ cdot d ^ {3}}} \ quad}$

${\ displaystyle \ tau _ {FL} \ quad}$	= Shear resistance [MN / m²]
${\ displaystyle M \ quad}$	= Torque [MNm]
${\ displaystyle d \ quad}$	= Dimension of the wing [m]

Norms and standards

DIN 4094 - subsoil - field investigation
- DIN 4094 - Part 4: Wing shear tests
DIN 4096 - subsoil - wing sounding - dimensions of the device, mode of operation, evaluation (until 2002)

Individual evidence

↑ Konrad Simmer: Soil Mechanics and Earth Static Calculations . Vieweg + Teubner Verlag, Wiesbaden 1994, ISBN 3-519-45231-6 , pp. 78 .

[1] Konrad Simmer: Soil Mechanics and Earth Static Calculations . Vieweg + Teubner Verlag, Wiesbaden 1994, ISBN 3-519-45231-6 , pp. 78 .