Evaluation Method for Slope Stability under Multianchor Support.

The multianchor support way is constantly adopted to reinforce the slope with soft layers, improve the mechanical behavior and enhance the load-bearing capacity of rock mass. To implement the optimal design for the anchorage system consisting of pretensioned anchors, the potential sliding planes in actual slope need to be found and the stability of reinforced slope needs to be evaluated. The plastic zone and shear stress rate are commonly used to judge the failure plane in the slope stability analysis. Based on these judgment criteria, the potential sliding planes are only given qualitatively and empirically. According to the ordinary definition of safety factor, the stress-based local factor of safety is proposed to analyze slope stability in this article. A stress-based program is developed to calculate the local factor of safety. Various constitutive models can be used as the yield criteria in this program. As an application, the aforementioned method and program are used to implement the simulation analysis for a cut slope during whole construction in the cases of without support and with staged support after staged excavation. The judgment result is compared with that one based on the plastic zone and shear stress rate. It is shown that the proposed method can provide a quantitative criterion estimating the potential sliding planes. The safety range can be visually demonstrated and the corresponding reinforcement can be reasonably taken. [ABSTRACT FROM AUTHOR]