Abstract:

The initial moisture content has important influences in collapsibility of loess. The collapsible deformation characteristics is studied in laboratory under a set of man-made samples with different moisture contents. And the microstructure of the samples are tested by using SEM technique, furthermore the microstructure of samples is analyzed by the quantitative method and fractal theory. The results are shown in the followings as：1)the initial moisture content obviously effects the collapsible deformation of loess in west of Liaoning. The collapsible deformation increases with the initial moisture content and increment of collapsible deformation is getting small under a certain pressure. 2)The relation between vertical stress and vertical strain for samples with different moisture contents can be all described by a hyperbola function. 3)The microstructure of loess samples is getting dense, the average number of pore of samples obviously increases and the pore area decreases after the sample is collapsed. The collapse is a process that small pore increases, fractal dimension decreases, and complexity of the pore increases.

Key words: collapsible deformation, fractal dimension of pore shape, quantitative analysis of pore, microstructure