Abstract: The disturbance factor D of the Hoek-Brown (HB) criterion reflects the degree of rock damage caused by blasting and excavation. In general, the value of D is used for the whole rock mass which is different from the real blasting project where the rock mass is divided into undisturbed and blast damaged zones with different mechanical parameters. In this research, a new parallel layer model is adopted for simulating blast damaged zone to study the effect of disturbance factor D on the factor of safety (FOS) of rock mass slopes. Slope stability analysis is carried out not only to analyze the effect of blast damaged zone on FOS of a slope, but also to analyze the three types of changes of D values in the blast damaged zone (convex, linear, concave) for a given slope. Analysis results show that the values of FOS of a slope decrease with the increase of T (thickness of damaged zone) value, and FOS tends to be more conservative when D changes with convex curve.

Key words: rock mass slope, stability analysis, disturbance factor D, Hoek-Brown, thickness T of damage zone