Numerical investigation on influence of dispersed rock particles on bimslope stability

Analysing the stability of bimslopes (i.e. slopes made of bimrock (block-in-matrix rock)) is challenging because bimrock has a complex internal structure. In the study reported here, a stochastic finite-element analysis with the shear-strength-reduction method was conducted to elaborate how dispersed oversized rock particles influence the stability of a vertical bimslope. Numerical models with different rock compositions were generated and analysed to characterise the definiteness and randomness. The factor of safety and the failure zone were used to establish the relationship between slope stability and fractal dimension (FD) of rock-size distribution and rock spatial variability. The numerical results show that the FD and spatial locations of the rock particles influence bimslope stability indirectly, with the key indicator for the skid resistance of a bimslope being the compactness of the rock composition crossing the sliding surface with given volumetric block proportion. This finding also highlights the validity and feasibility of stochastic analysis in outperforming deterministic analysis. Overall, the present findings offer a reference for further understanding of the collapse mechanism and reinforcement measures of existing bimslopes.