Numerical Simulation Research On Swelling Rock Slope Creep

With relatively low intensity, swelling rock has a comparatively obvious creep property. Meanwhile, since containing expansive mineral composition, swelling rock has the feature of swelling and softening after absorbing water. And its creep property will be more evident after absorbing water. This paper uses FLAC3D to conduct a creep numerical simulation research on two kinds of swelling rocks:one contains low moisture content (7.415%), the other high moisture content (23.35%). Under the condition of different rainfall infiltration depth and different surface saturated layer thickness, this paper makes a numerical simulation on the softening creep of swelling rock slope whose moisture content is 7.415%. The following results were obtained:It will accord with the engineering real condition better to consider creep effect on the stability of swelling rock slope.The swelling rock slope with low moisture content (7.415%) presents integral movement trend under the effect of creep and is in a stable state; the increment of shear strain area will be formed from toe to the top of the slope under the creep effect of swelling rock slope with high moisture content (23.35%), causing partial slide acceleration.The swelling rock slope creeping under the condition of rainfall infiltration and natural excavation is mainly shear failure and it also has the possibility of tension failure on the top. Rainfall infiltration on swelling rock slope will cause shear stress redistribution and the shear stress in slope will increase and shear failure will occur more easily near slope surface with the increase of infiltration depth.When the rainfall infiltration depth is 2 m and 7 m (the depth of saturated zone is 0.5 m), the slope creep displacement increases with the growth of infiltration depth. And the creep rate rises with the increase of infiltration depth during the stable stage. However, no landslide occurs. When the rainfall infiltration depth is 3 m (the depth of saturated zone is 1 m), the surface belt slide would take place very quickly, which shows that the thickness of saturated layer has a great impact on the stability of swelling rock slope.