Abstract:

The influence of the dip and inclination of joint and the ratio of soil thickness to rock thickness on the stability of jointed rock slope with overlying soil is researched in the present paper. The Mohr-Coulomb and Ubiquitous-Joint constitutive models and strength reduction method are used. Results of numerical simulation reveal that: for consequent-joint slope, when the consequent angle of joint is approximately equal to the internal friction angle of the rock, the safety factor is small and the damage area is large; while for anti-dip rock slope, the safety factor is large when the joint intersects vertically with the potential damage fracture of the slope. The effect of the dip of joint on slope stability reduces with the slope angle increasing. When the dip of joint is larger than the slope angle, slope angle is the main factor affecting the slope stability. When the thickness of soil layer is less than 4 meters, the slope safety factor increases with the thickness of soil layer increasing, and vise versa. When the thickness of the overlying soil is small, the slope toe should be the focus of support work, while the air side of the overlying soil should be supported as the key position when the thickness of the overlying soil is close to or larger than half of the slope height.

Key words: jointed rock slope, overlying soil, Ubiquitous-Joint mode, strength reduction method, stability, failure mode, numerical analysis