It is found that retardation coefficient, R d, of 85 Sr in unsaturated loess medium is not constant and increases with water content, θ , according to analyzing and fitting to the results obtained from the field tracer migration and laboratory simulation tests.

To simulate the strain localization in the failure process of geomaterials,a model with embedded localized softening bands incorporating into the idea of strong discontinuities is presented.

Considering the Laplace operator of plastic strains in the double yield functionst,he control equations of the generalized gradient-dependent plasticity model are established to describe both the strain localization characteristics and the basic mechanical characteristics of geomaterials.

As a product of geological history, rock and soil media process their special compositions and fabric structures so that their engineering behavior is very complicated.

The results show,in rock and soil media with thickness of dozens of meters and conductivity of some extent,the attenuation of peak values of NEMP can amount to more than an order an.

Recent development of strain localization of softening geo-materials;

In order to explore the strength and deformation mechanism of the geo-materials, some researches on the deformation and failure process in meso-scope must be performed.