关键词: 饱和破碎泥岩, 级配, Talbol幂指数, 粒度分布分形维数, 轴向应力

Abstract: By the compacting test on saturated crushed mudstone with different gradations, the curves of axial displacement and grain size distribution with variable axial stress are obtained; and the influence of Talbol exponent on the compaction deformation and grain size distribution is analyzed. In the end, the relationship between compression modulus and axial stress is established. The experimental results indicate that the compacting process of saturated crushed mudstone can be divided into two stages: the rapid deformation stage (0-4 MPa) and the slow deformation stage (after 4 MPa). And about 80% of the deformation occurs in the first stage. Axial displacement, compression modulus and fractal dimension can be fitted by the exponential functions of axial stress respectively. Under same axial stress, the axial displacement increases and the fractal dimension decreases with the Talbol power exponent increasing. After the axial stress exceeds 8 MPa, the fractal dimensions of samples with different grain size distributions are very close. In addition, with the further increase of the axial stress, the fractal dimension difference between samples with different gradations will continue to decrease; and finally, the fractal dimension will tend to be consistent. In the initial stage of loading, the compaction deformation of samples mainly results from movement of rock particles, and in the late loading, the compaction deformation mainly results from rock particles crushing.

Key words: saturated crushed mudstone, gradation, Talbol power exponent, fractal dimension of grain size distribution, axial stress