Micromeasurement of Soil Particle Movement in Geogridsoil Interface Direct Shear Test

Abstract:

Based on crosscorrelation theory,the particle image velocimetry (PIV) technology is applied to reinforcementsoil interface direct shear test,and the soil particle movement near interface during the direct shear test is measured and analyzed from the standpoint of microscopic view.Reinforcementsoil interface direct shear tests were performed under 50 and 87.5 kPa normal stress,respectively.By analyzing the results of a series of tests,several conclusions can be obtained:horizontal and vertical displacement of soil particles increase with shear displacement increasing,but the increasing rate decreases with shear displacement; in the direct shear tests the horizontal displacement is more evident than vertical movement and it attenuates with the distance to geogridsoil interface; the scope of soil particle displacement doesn’t exceed 45 mm,namely,the thickness of shear band is approximately 45 mm,which is 7～9 times of the average grain size of soil particle used in the direct shrear tests.

Key words:particle image velocimetry technology; direct shear test; micromeasurement; shear band