ANALYSIS OF CLAY MINERALS IN COLLAPSIBLE LOESS WITH SEM-EDS

The main reason of the occurrence of collapsibility of loess under pressure soaked by water is the loss of the cementation within its specific pore system, which leading to the deformation caused by the relative sliding among practices. The main cement in loess is the clay minerals attaching to the surface of the skeletal debris particles. There are a variety of clay minerals in loess. Due to their different hydraulic properties, the impact on the collapsible loess are also different. So the composition and its proportion of clay mineral, to some extent, can reflect the collapsibility of loess. Based on the spectrum analysis of main mineral elements at different depths in Yan'an, element mass conservation equations have been directly obtained. Then it is converted into an optimization problem. The main clay mineral contents of the loess are calculated by the means of simplex evolutionary method of standard linear programming. Moreover, a feasibility study of the method is carried out by comparing the calculating results with chemistry analysis result. The results show that the method meets request of precision and is proved to be an effective way of measuring clay mineral contents of loess. The acquisition of data is convenient and the quantitative analysis at fixed point under SEM platform can be realized.