Analysis of Changes in the Micromorphology of Sandstone Joint Surface under Dry-Wet Cycling

Abstract EN

Changes in the micromorphology of joint surface under dry-wet cycling have a direct effect on the mechanical properties of the jointed rock masses, which in turn affects the deformation stability of the bank slope of a reservoir.

In this study, we design and carry out a test that aims to quantity the effects of repeated rise and fall of a reservoir on the properties of a jointed rock masses.

The results are as follows: first, the roughness, local gradient, and undulation of the joint surface gradually decreased under repeated dry-wet cycling.

In addition, the height parameters and texture parameters showed a steep decrease followed by a slow decline.

The deterioration was particularly obvious over the first 5 dry-wet cycles.

Second, the roughness coefficient of the joint surface, the compressive strength of the face wall, and the basic friction angle were gradually reduced under dry-wet cycling.

The shear strength of the jointed rock masses (obtained both quantitatively and experimentally) showed a deteriorating trend controlled by the deterioration of the micromorphology, the strength of the face wall, and the frictional properties of the joint surface.

Finally, the dry-wet cycling process determined trends of changes in the microstructure parameters and mechanical properties of the joint surface.

Our research results provide a good basis for the analysis of the deterioration and failure of rock masses within the hydrofluctuation belt of a bank slope.