超小型せん断試験における粘性土の微視的せん断機構

Abstract

By using an Ultra Small Shear Box Test (USSBT) apparatus, which was developed by the author in order to introduce into a scanning electron microscope (SEM), the deformation characteristics of consolidated kaolin clay soils are examined.Micro-shearing process on the clay soil is observd by SEM and recorded by a video tape recorder. Then after, image processing of the particle movement during the shear deformation by USSBT are performed.Since the USSBT apparatus is in high vacuum chamber, the pore water in clay soils should be evaporated and the obtained micro-shearing process becomes to be quite different from that in the atmosphere.In this paper, therefore, a pore water exchange technique is tried by using a polyethylene grycol. As the results, the local discontinuity of the microshearing rate and the developing process of shearing layer are clearly revealed.