Anchorage performance of split-grouted rock bolt in fractured rock slope

To investigate the anchorage performance of split-grouted rock bolt in fractured rock slopes, a computational model was developed that accounts for rock bolt failure modes and the nonlinear mechanical behavior of the anchorage interface. Field pullout tests were conducted on three sets of split-grouted rock bolts, with ultimate strengths of 250.73 kN, 254.45 kN, and 253.66 kN, respectively. The computational model was then used to fit the experimental data, determining a peak shear strength of the anchorage interface as 0.55 MPa with a corresponding shear displacement of 3.31 mm and a residual shear strength of 0.17 MPa. The nonlinear mechanical characteristics of the anchorage interface were incorporated into numerical simulations to examine the effectiveness of split-grouted rock bolts in slopes with varying joint spacing and grouting radius. Results demonstrated that the combined reinforcement of rock bolts and grouting effectively enhanced the integrity of fragmented rock masses, significantly improving slope stability and altering the failure mode of fractured rock slopes. These conclusions provide valuable insights and practical guidance for the engineering design of split-grouted rock bolt reinforcement systems in fractured rock slope stabilization.