Trajectory Analysis and Risk Evaluation of Dangerous Rock Mass Instability of an Overhang Slope, Southwest of China

Table 6

Reference values of different geological slope sections [35, 36].

Slope section of lithology	Rn	Rt	Coefficient of rolling friction
The bedrock is exposed, the strong weathering sandstone, the rock quality is hard	0.53	0.99	0.4
The bedrock is exposed and strongly weathered mudstone	0.3	0.86	0.48
Weeds and shrubs covered by dense gravel piles, hard soil slope	0.25	0.84	0.58
Gravel soil and blocks of stone piled up	0.28	0.85	0.4
Loose gravel slope, soft soil slope	0.2	0.61	0.54