Disturbance range characterization and reinforcement design method of concealed bedding slope

The concealed bedding slopes exhibit sudden and extensive failure characteristics, harboring significant safety hazards. It is crucial to employ rapid and accurate methods to determine excavation disturbance ranges and reinforcement forces to prevent such slope disasters. This paper first analyzes the failure characteristics of slope excavation to reveal the mechanism of slope failure. Secondly, a novel method is proposed to calculate excavation disturbance ranges and solve for active reinforcement forces. Thirdly, the rationality of this method is validated through numerical simulation experiments. Finally, the method is applied to engineering. The results are as follows:(1) Excavation induces plastic shear failure of structural planes first, and the strength of the structural plane will be reduced, resulting in extrusion shear deformation of the rock mass at the foot of the slope under greater unidirectional load along the structural plane, forming a shear sliding surface. (2) From both strength and deformation perspectives, a method for calculating disturbance ranges in excavated slopes is proposed. This method determines key indicators for analyzing two disturbance range factors: ultimate height and disturbance thickness. The disturbance range is divided into shear plastic zones and traction sliding zones. (3) An active reinforcement design method is proposed considering the timing, scope, and force of reinforcement. The disturbance thickness is used to determine the reinforcement range, while the ultimate height is used to determine the timing of reinforcement. Active reinforcement forces are calculated based on the equilibrium of forces and deformation amounts. (4) A comparison with the Finite Element Method (FEM) shows that during excavation, the disturbance ranges and reinforcement forces calculated using this method are slightly larger than those obtained from the FEM. The calculations are fast, and as the excavation height approaches the limit slope height, the disturbance thickness and horizontal deformations closely match the FEM results, ensuring safety. It can provide monitoring, early warning and reinforcement guidance for bedding slope construction.