By utilizing an improved direct shear creep apparatus

exploration to the rheological characteristics of soft clayey soil affected by mineral composition and its content in soil is performed; and rheological characteristics of three sets of soft clay samples with different contents of kaoline and bentonite

respectively

are tested under the same test conditions. The test results show that mineral composition and its content are two important factors on rheological behavior of soil; the viscosity coefficient of the soft clay reduces as the increase of the clayey mineral content; i.e. that rheological strain resistance decreases with the increase of the clayey mineral content. It is concluded that clayey mineral affects soil rheology characteristics by the way of water bounded mineral particle surface; furthermore

firmly bound water is a key factor and loosely bound water is only a secondary factor. The test results make a contribution to understanding of the origins of soil rheology and are of guiding significance for improvement and perfection on existing computing theories of rheology deformation of soft soil.