The Influence of Temperature and Shear Contraction/Dilation on the Frictional Characteristics of Kaolin Clay under Different Shear/Drainage Speed

This study aims at exploring the mechanisms influence of the frictional characteristics ofkaolin clay submerged in water. In addition, the critical velocity dominating the sheardisplacement strengthening and weakening will be identified. These two aims are essential tounderstand the fault dynamics and the large landslide initiation and kinematics. We design therotary shear tests under different shear velocity and different drainage conditions. The low tohigh velocity rotary shear apparatus was used to measure the equivalent friction coefficient ofwet kaolin clay under a normal stress of 1 MPa. The shear velocity ranged from 10-6 to 1 m/s.The drainage conditions include radial (conventional tests, relatively undrain) and doubledrainage conditions (relatively drain). The temperature variation during shearing will becontinuously monitored. We anticipated the results can be useful to discover the mechanismsdominating the frictional characteristics (it is believe that the friction variation should relateto the excess pore pressure generation and dissipation) of the clay using monitoredtemperature and shear contraction/dilation. The results could be relevant to the study of largelandslide from creeping tuning into catastrophic failure.