INVESTIGATION ON CONCRETE MICROSTRUCTURAL EVOLUTION AND SLOPE STABILITY BASED ON COUPLED FRACTAL FLUID–STRUCTURE MODEL

Abstract

Slope instability is a common type of damage in embankment dams. Analyzing its microstructural changes during water transport is beneficial to identify the critical damage point in more detail. To this end, we closely link both diffused water molecule and damaged concrete. On the basis of the original research on fractal theory, the fractal permeability model for the pore system is established. At the same time, considering the pore structure characteristics of concrete, the models for fluid–solid coupling inside and outside the embankment are established in this work. The simulated results and experimental data agree well, thus verifying the correctness of the proposed models. The changes of concrete pore structures under different water pressure and different initial porosities are simulated by numerical methods. The results show that: (1) with the increase of the safety factor, the slope of the embankment begins to be damaged at the critical point and then completely destabilized; (2) with the increase of the pressure head, the change of the fractal dimension of the embankment’s porosity from the top to the bottom changes from linear to nonlinear. (3) The initial porosity of concrete is proportional to the evolution of concrete pore structure. From a technical point of view, this study can contribute the effective technical guidance for related professional practitioners in the analysis of embankment slope stability from a microscopic point of view.